A Beginner's Guide to Growing Strawberries

Photo taken at Farm in Ngobet

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Acknowledgement

The compilation of this manual would not have been possible

without the financial support provided by Lutheran World Relief.
We are particularly grateful to LWR program staff including the
director, who made valuable comments and contribution.
The content of this manual was a consultative process, propelled
by many individuals and organizations, particularly from the
Ministry of Agriculture. We would like to extend my sincere
thanks to all of them.

We are highly indebted to key EcoAgribusiness Limited (EAL)

and Help Self Help Centre (HSHC) staff for helping in the
information research and in consulting farmers on what they might
require. Their kind co-operation, guidance and encouragement
were exemplary.

I would like to express my special gratitude and thanks to all Nyeri

county farmers in advance, who are expected to bear with all the
information presented in this manual.

Authored by;

Joyce K. Kuraru, Agriculture extension and horticulture expert

Peter K .Mwangi, information, communication technology

Youth-net enterprises,
Po Box 15
Naromoru, Nyeri County
youthnet.farm@gmail.com

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The Target User of The Manual.

This manual is meant to be used as a reference by extension

officers, community knowledge workers, producer organizations
and other relevant community organizations. It is detailed not to
miss any aspect necessary in commercial cultivation of strawberry.

While it is not recommended for distribution to farming

population, the manual will be available to any farmers who are
able to utilize it effectively. This category of farmers must
purchase the manual, at a price determined by HSHC/LWR to
avoid wastage. A simplified version of the manual in form of a
brochure is available to all farmers

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Contents
A Beginner's Guide to Growing Strawberries ................................. 1
Acknowledgement ....................................................................... 2
Target Users of the Manual ...................................................... 3
3. Table of Contents ................................................................ 4
4. Introduction .......................................................................... 5
5. Economy of Strawberry ....................................................... 7
7. Strawberry Varieties ................................................................ 9
9.Factors to concider when growing straberry .................. 12
12. Straberry Propagations .................................................. 15
15. Envinmental Conditions ............................................. 16
16. Strawberry Cultivations ................................................... 20
20. Planting Systems ............................................................ 22
22. Creating special Growing Environments ......................... 26
26. Planting Strawberry Under Greenhouse Conditions ........ 27
27.Plastic Culture ................................................................. 28
28. Special Sensivity of Straberry ........................................... 29
29.Strawberry Plant Nutrients .............................................. 32
32. How to Grow Organic Certified Straberry ..................... 36
36. Diseases and Insect Control …………………………………42
42. Strawberry Harvesting ………………………………………43
43. Post Harvesting Handling …………………………………...44
44. Market for Strawberry………………………………………..48
48. Financial Gains and Cost Benefit Analysis …………………50
50. Nutrition Value of Strawberry……………………………….51

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 1. Introduction

Strawberry farming is a multi-billion dollar business around the

world. The fruit is a high value crop for export and local market,
though the export market has not been exploited in Kenya due to
limited supplies. The estimated total strawberry production in
Kenya is 1487 tons while the demand is over 15,000 tons
(Horticulture Validated Report, 2014). It is worth noting that 90
percent of strawberry (fresh and pulp) is imported into Kenya
(Horticulture Crop Development Authority).

Gradually strawberries is emerged, a sought after fruit in the

Kenyan market prompting many farmers interest to venture into
the business and establish strawberry farms with the hopes of
earning from it. Furthermore farmers are leaning towards replacing
the traditional maize and wheat type of farming with more
profitable and climate resilient ways that combines both
sustainability and profitability. The effect of climate change on
rain fed agriculture is making this traditional farming system
increasingly untenable.

The strawberry is the most widely adaptable of the small fruits and
can be grown throughout Kenya. The wide variation in climates
within the Country and the wide adaptation of the strawberry plant
permit production, harvesting and marketing throughout the year.
However, currently in Kenya it is generally cultivated in the
central region. Here, it is increasingly becoming an opportunity
particularly for the youth, for self employment and livelihood
improvement.

Strawberries are easy to grow, require minimal land and thrive

well in a wide range of temperatures ranging from mild to hot.
Strawberries are so versatile – they just need sun, fertile, well-
drained soil and modest amount of water. Avoid areas prone to
frost and soils that have previously grown potatoes, tomatoes
because they have a common disease (verticillium wilt). Also
avoid sites which have been infested with sedge, nut grass, quack
grass, Johnson grass.
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 2. Economy of Strawberry

Strawberry (Fragaria spp.) is a high value crop with great potential

for income generation and employment creation through
cultivation and application in value added products including
yogurt, fresh juice and jam. Strawberry is a delicious fruit taken
fresh in several ways. It also makes excellent ice cream and Jam on
account of its rich aroma, and is also a good source of vitamin C. It
is a soft and a highly perishable fruit, often shipped in frozen
condition in Western countries. The estimated total strawberry
production in Kenya is 1487 tons while the demand is over 15,000
tons (Horticulture Validated Report, 2014). It is worth noting that
90 percent of strawberry (fresh and pulp) is imported into Kenya
(Horticulture Crop Development Authority).

Companies like Trufood, Zesta, Brookside, KCC among others are

importing these strawberries to use in their daily production needs
with outlets such as supermarkets and hotels requesting for more of
them day in day out. The fruits can also contribute to household
nutrition through availability of vitamins. Although a ready market
exists with high demand especially in urban areas, strawberries are
in short supply and highly costly in Kenya’s markets. Besides local
demand substantial markets exist for strawberries in foreign
markets, especially in the European Union. The scarcity is partly
due to limited production, since many prospective farmers have not
been able to engage in full-scale production. Production constraints
include scarcity and high cost of planting materials, lack of
knowledge on appropriate planting and crop management
practices. There is also low awareness on the huge potential of the
crop and available market opportunities.

Strawberry is a high value crop that requires relatively small piece

of land to produce and little amount of water at 25mm/plant/week.
It’s less bulky, has ready market and will provide enormous
income and employment opportunities in the rural context. Unlike
the staple crops grown by small scale farmers, strawberry is a high
value cash crop that can be grown in a small parcel of land and it’s
less labor intensive. Once established, strawberry is harvested 2- 3
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times a week throughout the year for up to three years when a
cycle change is made. From the smallest farm of 50 ft. x100ft (or
1/8 acres a farmer will earn a minimum of USD 14,000 over the
production cycle.

By growing improved strawberry variety, a modest estimate is that

each beneficiary household will earn $8286 per annum or $22.7
per day from the cultivation of a quarter of an acre. For a quarter of
an acre, a farmer will require to invest $2208 in splits (propagation
materials), irrigation, labor and other inputs per annum. With
proper management of the cropping regime, it is estimated that by
the 12th month, a farmer would have recouped his or her
investment.

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 3. Strawberry Varieties

Pajaro: It is a fast-growing variety, popular for large berries and

good flavor.

Chandler: This is a high-yielding plant that produces large and

firm fruits within 60–75 days. The fruits are not only large but
have good flavor and firm skin.

Selva: A neutral day variety producing small berries with good

flavor and color.

Fern: A neutral day variety with heavy yield of large fruits but
lighter than all the others.

Aiko: Uniform, large, long fruit of conical shape, with a pointed

end, firm flesh, pale red color, slightly sweet, very resistant to
transport and high yield.

San Andreas their External and internal fruit color is dark. They
produce fruits consistently throughout the season. One downside is
that san Andrea’s produces many runners that must be cut to
maintain high production.

Douglas: Matures early, has clear foliage and offers good fruits of
elongate conical shape and orange-red color. It has firm flesh,
which is red-colored with a pink centre, and a good taste.

The crop is high-yielding. Other varieties include Nanandreas,

Albion, Red glory, Manhattan.

Recommended Varieties for Nyeri County

Try planting more than one variety. Each will respond differently
to conditions. Many farmers in the region have successfully been
growing these varieties;

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• Chandler is best suited for the central and rift valley parts
of Kenya because of its ability to produce high yield
plants

• San andreas also performs very well in Nyeri county due

to its high and consistent productivity with ability to resist
common diseases

• Douglas has also proved to be a high performer strawberry

fruit in many areas of the country. Famers prefer it due to
its early maturity, color, taste and its shape.
•

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 4. Factors to Consider When Growing Strawberry

Choose your planting site carefully. Choosing an area conducive to

growing strawberries is a critical step in commercializing
strawberries cultivation.

There are several factors that need to be considered when selecting

a site for commercial strawberry cultivation.

Water: Choose a site where there is ready access to a water

supply. This can be a permanent river, spring, reliable water
project or borehole

Quality of Irrigation Water: Irrigation is essential for high-yield

strawberry production. Since strawberry plants are shallow rooted,
permanent moisture is necessary to maximize production. An
average of 300mm to 450mm (12 to 18 inches) of irrigation water
is required over the growing season. Water quality should be
adhered to, regardless of the water application purpose. Drip
irrigation is increasingly being recommended for efficient water
utilization and conservation in strawberry growing.

Soil type: Strawberry plants grow and produce satisfactorily in a

wide range of soil types, from sandy to clay loams. Strawberry will
respond positively to high organic matter content in the soil. The
best soil for strawberry production is a deep, well drained sandy
loam, well supplied with humus (over 2% organic matter).Heavy
clay soils that are usually poorly drained encourage disease
development and impede field operations including weeding.
Coarse textured sandy soils are often infertile and droughty, and
require more frequent irrigation and greater attention including
fertilization practices. Plants established in low-lying mucky
organic soils are more vulnerable to frost injury.

Soil Surface Drainage: It is important to pick a site that has good

soil drainage and surface drainage. Although strawberry plants
need constant moisture to thrive, the plants will rot if left in
standing water due to poor site drainage. In areas where there is
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poor drainage or heavy soils, constructing a raised bed for the
strawberry plants should facilitate better drainage. The strawberry
bed should be elevated, at minimum, six to eight inches.

PH requirements: In order to grow strawberries most effectively,

the soil needs to be slightly acidic. Strawberry plants will grow
best in the soils that has a pH between 5.0 and 7.0, but 5.8 to 6.2 is
ideal for maximum growth and production. It is recommended that
farmers to have soil testing or collectively obtain professional soil
testing services provided by government agencies such as Kenya
Agricultural and Livestock Research Organization (KALRO)).
Private companies such as Soil-Cares Ltd and Crop Nutrition
Laboratory Services (Crop-nuts) also offer testing services. Before
planting strawberries, you should test your soil and amend it as
indicated to create the best possible environment.

Common amendments are lime and manure. If test results show

high PH lime should be applied prior to planting and tilled in
thoroughly with the soil. Compost or aged manure from cows is
also added, usually at a rate of 2 to 5 bushels per 100 square feet.

Terrain Slope: Strawberries should ideally be planted on slightly

inclined slopes. Avoid cultivation of straw berries on steep slopes.
Plantings on 10% to 15% on slopes are likely to erode, with some
plants being buried and others washed out of the soil. If sloping
sites must be used, rows running across the slope or on the contour
and with a wide row width are recommended.

Sun light: Strawberries need full sun to produce the largest yields.
While harvestable berries will be produced with as little as six
hours of direct sun a day, it is best to select a site that is clear of
other tall or shadow-casting trees or plants. Planting strawberries
away from large trees also is important so that the tree root system
doesn’t compete with and siphon away needed moisture from the
growing strawberry plants.

Variety: Before you begin growing strawberries in your garden,

you need to determine which variety of strawberry plant you want
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to grow. As new and improved strawberry cultivars are developed
annually, it is important to liaise with the relevant ministry for any
new developments. Currently the best cultivars for Kenya are
Sanhedrin and Chandra. You are advised to visit Kenya
Agricultural and Livestock Research Organization (KALRO) or
the Help Self Help Centre (HSHC), before engaging in this
emerging lucrative cropping system.

Certified Materials: Another factor to consider when picking

strawberry variety is susceptibility to Verticillium fungus. This
fungus causes the most common strawberry disease, Verticillium
wilt (or Verticillium rot), which will end fruit production by killing
growing strawberries. Since there is no practical way to kill the
fungus once infection sets in, this difficult disease is best prevented
by obtaining and planting strawberry plant varieties that are
certified to be resistant to Verticillium wilt?

Other crops: Strawberries should not be planted in soils where

strawberries, raspberries, vine crops, alfalfa, potatoes, tomatoes,
peppers, eggplants, beans, carrots, okra or sod have been grown in
any of the previous four years, unless the soil has been fumigated.
Such sites are likely to contain disease and insect pests that may
attack plants. These crops also carry the root rot fungus
Verticillium, which also attacks strawberries.

In addition, do not plant strawberries into recently plowed grass

sod areas. This can lead to devastating weed problems and damage
by white grubs, a common turf pest that will feed upon strawberry
roots.

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 5. Strawberry Propagation

Strawberries are planted as splits. Strawberries have runners which

grow away from the parent plant and in turn attach to the ground
forming roots. This can be split from the parent plant to act as
seeds for another plant.

The plants may be allowed to set as many runners as possible but

not allowed to set any fruits. All the plants with good root system
should be utilized to set a new plantation. Given the best attention
and care, a single plant usually produces 12 to 18 runners.

Farmers are advised to gets splits which are transplants from the
parent plant so as to get fruits of equal quality as the parent plant.
There is a possibility that hybrid plants produce fruits of lesser
quality as they are not fully made up of one parent plant.

In strawberries gardening propagation is done using vegetative

material namely splits of the strawberries crown. There are many
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 sources of seedlings in Kenya, but farmers must be careful to
purchase from only trusted suppliers. This is because splits from
different varieties look the same and you might buy the wrong one.
The splits must be disease free.

First know the basic morphology of what variety you want to buy.
Then visit the selling farm as they pluck out the splits. That way
you are assured of purchasing the right variety.

The cost of good strawberry seedling will range from KSH 20-
50/split

Table 1.1: The list of strawberries split suppliers in Nyeri

County.

Companies Cost/split Email Phone contact

1. Nabulu Farm 20-50 admin@pri-kenya.org +254 (725) 618 737

2. FaCT Ltd farm. 45-65 Mwangi.maina@ku.ac.ke

3. KARLO) Njoro 30 info@kalro.org. 0723-662773

4. KARLO THKA 30 director.hri@kalro.org. 020- 2055038.

5. Egerton 30 nfo@egerton.ac.ke 0512217891/2

University/
Department of
Crops,
Horticulture
and Soils

6. Ngera Farm 20 0798185505

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Management of Splits

You should select disease-free, healthy splits. When sourcing from

your farm, select plants that have large crowns with healthy, light-
colored roots. If externally sourced, splits should be carefully
inspected of mold, the moldy one being rejected.

Splits sourced from a distant and cannot be planted immediately,

must be wrapped in wet paper towels or bags and stored in room
temperature, for a maximum seven days. They must not be
exposed to dryness or exposed to direct sunlight unless planned for
immediate planting.

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 6. Environmental Conditions

Temperature
Day-neutral strawberries will flower and set strawberries whenever
the temperature is in the range of 200C to 290C (350F to 850F).
290C is considered the upper limit at which day-neutral
strawberries will produce flowers. Those growing strawberry in
greenhouses should observe this fact and try and adjust
temperature conditions.

Soil pH
Strawberries prefer slightly acidic soils with a pH of between 5.5
and 6.5. Too low pH values may require applications of ground
limestone to increase the pH of more acid soils. Soil pH level over
8 adversely affects certain strawberry nutrients, especially the iron
levels in certain cultivars. Yellowing in strawberries is also
common where soil pH is high. The use of green manures and
acidifying fertilizers can reduce the soil pH to some degree.

Soil Salinity and Alkalinity

Strawberry plants are extremely sensitive to salinity, especially at
the transplant stage. Highly alkaline soils can occur in bands or
patches throughout a field. This can cause yellowing or chlorosis
of the plants, a condition that can lead to significant yield losses or
complete plant die-back.

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 7. Strawberry Cultivation – Field Operations

Land preparation: Strawberries cultivation starts with thorough

land preparation in order to raise a vigorous crop. Test the soil for
PH as strawberry does the best in areas where the soil is in 6 to 6.2
PH. The soil needs to be well drained and weed-free. A bed raised
to 15cm with a width of 1metre by any convenient length should
be prepared, and well fine cattle/goat/sheep manure incorporated
into the soil at a rate of a 20 kg bucket per square meter.

NB. Do not grow strawberries in land parcel previously

cultivated with such plants raspberries and egg plants, at least
for the past three years. (Please refer for the previous section
on not to do plants)

Planting: Dig out a hole big enough to spread out the roots of the
splits. In the bottom of the hole, create a mound or hill of soil that
is flush with the surrounding soil level. Put the strawberry plant on
top of the hill inside the hole so that the crown is at soil level and
spread the roots out down the sides of the hill. Fill in the hole and
ensure that the soil level is even with the middle of the crown.
Planting too shallow may cause the roots to dry out before they
establish, and planting too deep can also damage growing
strawberries.

See the figure below for proper crown placement.

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18
It is very important: If you bury the crown, the plant could easily
rot. The crown is what looks like the base of the plant before the
roots start.

This crown cannot be covered when planting the strawberry plant,

either in garden beds or containers. However, it should not be left
too exposed either, always check to ensure that the crown is sitting
just above the soil. Water them well.

Once the plants are planted, press to firm the soil around the roots
and then water thoroughly.

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Spacing: The strawberries should be planted on a wet ground
ideally on raised beds with a spacing of between 30cm. The rows
should be 60cm apart. Strawberries are runners and it is therefore
necessary to ensure that at least 30 cm between plants remains.

Fertilizer and manure application: Compost should be applied

every so often, during planting and after every seasonal harvesting.
During the fruiting period foliar feeds may be applied to boost the
yields. Rooting media or enzymes which include plantone and
Anatone may also be applied. Anatone is a broad spectrum for
roots, flower stimulation and fruit retention and may enhance
strawberry plant establishment

Watering: Irrigate daily in the afternoon during the first month

after planting for good crop establishment and 2-3 times a week
from the second month from initial planting onwards. Use of drip
irrigation is recommended as it waters at the root and considerably
conserves the scarce resource.

Mulching: Mulching is recommended after planting in order to

conserve moisture, control weeds and keep strawberries clean.

Pruning/stripping: Thinning to 2- 3 splits per crown should be

done every 7 months to allow rejuvenation and increase strawberry
yields.

De-blossoming: To increase fruit production, prune off the flowers

the first time they appear. This is also recommended to avoid
premature fruiting, which may lead to stunting and poor
development of the crop.

Removing the flowers also promotes root and runner development,

thereby insuring a large crop the following year.

Weeding: Weeding is one of the most important practices in a new

strawberry planting and it should be done frequently (once a week)
for the first 6 to 8 weeks. Weeding kills the weeds and loosens soil
for better runner penetration.
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 8. Planting Systems

There are several methods to planting strawberries but for our

purpose we will only illustrate two-Matted and Hill system.

8.1 The Matted Row System:

The matted row system works well for any cultivar that sends out
a lot of runners. To grow strawberries with this system, set plants
about 24 inches apart in rows 4 feet apart. Allow runners to spread
freely and root at will within the row to form a crisscrossed, matted
row about 24 inches wide.

This system of growing strawberries will produce the largest

number of strawberries, but the quality of berries does not match
the hill system. It is good in situations where beeries are for
processing into value added products.

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8.2 Hill System (Mound System)

This method requires the most work and yields the biggest berries.
Set plants 30cm (1 ft) apart in rows 60cm (2ft) apart. You can also
plant double or triple rows with 30cm between each row and 60cm
between double or triple rows and let the runners root. When
planting using the hill system, plants must be turned under every
two to three years. It is recommended to remove flowers from the
plant the first growing season. The second season will be the best
harvest when flowers are removed the first season. Decreasing in
quantity and quality the following year, some growers choose to
replant each year.

All runners are removed from every strawberry plant in the hill
system as soon as they are identified. Removing the runners causes
all the productive capacity of the mother plants to remain with the
mother plants. This energy will result in additional lateral crowns
adjacent to the original crown and more flower stalks for fruiting.
The hill system is often preferred because it results in a higher
quantity of higher quality berries, while the matted row system
usually produces a higher total number of strawberries.

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 9. Creating Special Growing Environment

Once the plants are in the ground, it is important to create an

environment that is most conducive to growing strawberries.

Mulching

After you’ve planted your strawberry plants, mulch the strawberry

bed with shredded leaves, compost, or straw. Mulching also keeps
the soil temperature down, mitigates the weed problem, and keeps
the fruit cleaner by keeping the strawberries off of the dirt. Most
varieties of strawberries produce better when their roots are in
cooler soil.

Water

Irrigation is essential for high-yield strawberry production. Since

strawberry plants are shallow rooted, permanent moisture is
necessary to maximize production. An average of 300mm to
450mm (12 to 18 inches) of irrigation water is required over the
growing season. Growing strawberry plants require a permanent
source of water, as regular watering is a must. Water strawberry
plants regularly and more often in hot, dry weather and maintain a
constant moist environment. Water should be provided to the
plants either through rainfall or direct irrigation. Up to two inches
of water can be given while the fruit is forming, from early bloom
until the end of harvest.

Water at the base of the plants, not on their leaves or fruits, and
also don't let water splash on the leaves or fruit, as this can
encourage disease. Also, try to water in the morning so the surface
water can evaporate by evening.

The best method is drip lines and direct-point watering (put hose
on low pressure and water at base of plants)

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Protection

Strawberries must be protected from birds, snails and heavy rain.

Birds will eat the fruits, slugs eat the leaves while the rain cause
flower drop. You can protect the crop from birds and direct rain
by covering your rows with bird netting. Additionally, copper
ribbon will keep the snails away.

Renovation

Renovation is an important part of strawberry care. Strawberry

beds can usually be carried over for 3 to 5 years of more if the
plants are vigorous, the bed is kept weed-free, and the planting is
properly renewed or renovated every year. This is done to give
new runner plants the chance to replace old or weakened plants.
The bed should be renovated shortly after the harvest is complete.

To renovate, thin the plants in the rows to about 15 cm (5 to 6

plants per square foot is the maximum acceptable). Then, mow the
tops of the plants to one inch above the crowns. Take special care
not to damage the crowns. If the foliage is disease-free, rake the
leaves and compost them or incorporate them into the soil.
Fertilize with a balanced (NPK, 10-10-10) fertilizer. Narrow the
rows to between 30 and 45 cm by hoeing or tilling.

A good, aggressive renovation effort will see about half of the

strawberry plants removed. After plant removal, work the mulch
medium into the soil with a tiller. Since strawberries have a
shallow root system, spreading a thin layer of soil (about a half
inch) around the crowns can help facilitate new root development.

Continue to water the plants at least 1 inch per week for 3 weeks
and maintain the planting as weed-free. Allow early runner plants
to root where they will be maintained until your desired row width
is re-established.

Irrigate the planting well, wetting the soil to a depth of 15cm (6

inches). During the rest of the growing season, irrigate to provide
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25mm (1 inch) of water per week, and continue to control weeds.
Runner plants will emerge and should be placed to fill out the row
to the desired 60cm (2 foot) width, similar to the planting year.

Keep the planting healthy and vigorous throughout by controlling

weeds, maintaining the proper plant density and row width, and
watering regularly.

NB: Whenever you begin to notice the growing strawberries

losing vigor or struggling to maintain their vitality, or if your
yields begin to decrease, you may have reached the end of your
strawberry bed’s lifetime. When this occurs, start over with
new plants in a new area.

Pollination

The more heavily pollinated a strawberry is, the bigger and better
the berry becomes.

NB: The more pollination that occurs, the bigger your

strawberries and your overall yield.

There are three different methods to enhance pollination in

strawberries:

Hermaphroditic (self fertile)

Strawberry plants produce flowers that are hermaphroditic. That

means each strawberry flower contains both the male stamen and
the female pistil, but must be disturbed by wind or other movement
for pollination to take place.

Insects

This is actually the best method of strawberry pollination. Insects,

especially bees, will find and pollinate strawberry flowers quite
effectively. Butterfly and beetles will also fertilize the strawberry
(albeit less effectively) by spreading pollen around.
25
Plant plants with flowers that attract bees such as sunflowers
around the strawberry beds. Remember, insect diversity is the best
options.

Wind

This is not a substitute for insects, but shoul be seen as

complimentary.Even gentle breezes are sufficient to transfer the
pollen of the few millimeters from stamen to pistil. So, even in the
absence of insects (greenhouses), strawberry pollination can still
occur.

Benefits of Strawberry Pollination

1. Heavy pollination increases the overall yield of strawberry

plants.

2. Cross pollination leads to decreased deformations and an

overall higher-quality.

3. Cross pollination results in larger overall strawberries than self-

pollination or same-variety pollination.

4. Natural strawberry pollination increases commercial viability

also. Bee pollination results in brighter and redder berries, which
are more pleasing to customers. Natural pollination also improves
quality by reducing spoilage.

26
 10. Planting strawberry under Greenhouses Condition

An ever-increasing hectare of strawberries is produced under

greenhouses condition, equipped with the modern production
inputs. Green houses are good especially in controlling insects,
birds and impact of heavy rains. All these in combination or singly
have the capacity to destroy more than half of the crop.

Planting arrangement

Planting arrangement is more or less the same as in the open field,

but there are other differences

Irrigation and Nutrigation

Plants are best irrigated in protected cultivation with dripping

systems. It is advisable for plants to receive nutrients and other
dissolvable inputs with every irrigation session.

Pollination

Under greenhouse conditions, the activity of natural agents like

wind, honeybees, and other insects is highly restricted by the
protective structure. Bee’s provide good pollination for strawberry
plants and performs much better than hand pollination. Therefore,
the placing of beehives close to the green house is absolutely
essential to ensure good pollination. One or two beehive with good
access to the greenhouse is sufficient for pollination about 8,000
strawberry plants (half acre of strawberries plants).

27
 10. Plastic culture

The bulk of modern commercial production uses the plasticulture

system. In this method, raised beds are formed each year, are
fumigated and are covered with large plastic sheets, under which
the irrigation tubing is installed. Plants are planted through holes
punched in the covering. Runners are removed from the plants as
they appear, to encourage the plants to put most of their energy
into fruit development.
The main advantages of this mulch are:

• A considerable increase in soil temperature of the active

root zone of the plants. This enhances plant physiology
and enables much earlier flowering and fruit bearing.
• Prevention against weed growth, thereby saving on
herbicides and work
• Protection of the beds from erosion by strong rainfall

28
 11. Special Sensitivities of Strawberries

Salinity

The strawberry is one of the most salt-sensitive crops. Salinity in

the root zone radically decreases root development from the crown,
water uptake, growth rate, and fruit yield. Salinity damage can be
due to high concentration of salts in the root zone, the
accumulation of specific ions to toxic levels, or imbalances in ion
ratios. This is brought about by poor drainage, salty irrigation
water and excessive fertilization or application to wet foliage

Symptoms of salt injury include dry and brown leaf margins,

brittle leaves, stunted plant growth and dead roots and plants.
There are a number of solutions to salinity

• Maintain adequate drainage to remove excess salts from the

root zone.
• Ensure deep plowing to mix the soil more completely.
• Avoid formation of hard pans in the soil.
• Maintain high bed height .High beds provide improved
drainage.
• Add organic amendments to heavy soils to increase
drainage.

29
 12. Strawberry Plant Nutrients

Maintaining balanced nutrients levels helps growing strawberry

plants reach their maximum potential. It is recommended that:

First, a balanced (10-10-10) fertilizer should be added just before

planting strawberry plants. Add one to two pounds of fertilizer per
100 square feet. This helps increase the nitrogen levels in the soil.

Second, apply another round of fertilizer in the sixth month and

again in a year, depending on plant growth.

Third, strawberries can be fertilized after every harvest. This is

done to keep the plants vigorous. Be sure to water the fertilizer
well to get it to soak in down to the roots of the growing
strawberries.

NB: Appropriate application is highly advised. If you apply too

much fertilizer, you will get excessive leaf growth and poor
production of flower stalks.

On the other hand applying fertilizer to wet strawberry plants

can result in phytotoxicity.

No fertilizer particles should remain lodged in the plants.

Nitrogen Levels

Nitrogen is an important nutrient and will substantially affect

quality and yield of strawberries. The plant quickly responds to
every positive or negative change in its nitrogen status. Application
of nitrogen fertilizers stimulates vegetative growth of leaves,
petioles and shoots.

30
However, heavy applications are not recommended because
excessive vegetative growth will result in dense leaf canopy that
will retard developing of fruit, and increase chances of fruit rot
diseases (gray mold). Excessive nitrogen also causes fruit
softening, delayed ripening, decreased yield and increased
powdery mildew and mite pressure.

Nitrogen deficiency is manifested in middle-aged leaves turning

yellow.

Typical nitrogen fertilizers used on strawberries include urea (46%

N), ammonium nitrate (34% N), potassium nitrate (13% N) and
calcium nitrate (15% N).

31
 The following table shows the sysmptoms of lack of nutrients:

Leaf Possible Causes

Uniform yellowing Nitrogen or sulfur deficiency, or
poor soil drainage
Yellowing with veins remaining Zinc, manganese or iron
green deficiency
Yellowing of leaf base Copper deficiency
Darkening of leaf base or center Potassium deficiency
vein
Dark green foliage Phosphorus deficiency
Leaf scorch Potassium or magnesium
deficiency or salt toxicity
Growing points damaged with Calcium or boron deficiency
restricted growth
Brown-black veins Copper or boron deficiency

Fruits Symptoms Possible Causes

Poor pollination (bumpy fruit) Boron deficiency, frost damage or
high temperature during
flowering
Hard seed Calcium deficiency
Soft, poor colour and flavor Potassium deficiency

32
 13. How to Grow Certified Organic Strawberries

Conventional growing methods use fumigants, chemicals, and

other methods to maximize production and profits. But the market
is becoming increasingly concerned over agrochemical based
production systems due to their deleterious effect on human
health. Hence the trend toward organic produce has opened a new
opportunity for growers to supply certain niche market that is
expanding every day. This market offers premium price over
conventionally-grown counterparts.

Organic strawberries must be grown free from conventional

pesticides and chemicals. To achieve this natural fertilizers rather
than chemical-based substitutes are vital part of the strawberry
growing process. Specifically strawberry plants have a higher
relative nitrogen demand especially in early stages of growth. To
maintain productivity and nitrogen levels, in the absence of agro-
chemicals; you'll need to use organic fertilizers.

To get your organic strawberry plants off to a good start, clear the
area of all weeds and grass, and dig two to three inches of compost
into the top few inches of soil.

Blood meal is a good option as it has 13% nitrogen. Other organic

sources of nitrogen include fish meal, soy meal, and alfalfa
meal. Aged manure is also a good source of nitrogen, but you have
to be careful to not supply too much nitrogen to your strawberries
as that can cause excess vegetative production and fewer berries.
Too much nitrogen can kill or burn up strawberries. However, so
do not put raw, fresh chicken manure on strawberries (or any other
extremely nitrogen-rich material).

1. Apply well done manure to the soil surrounding strawberry

plants at a rate of 1 kg and make sure it is rich in
phosphorus. Young strawberry plants require phosphorous
for healthy root growth and greater fruit production.

33
 2. Mix seaweed manure into the soil surrounding plants to
release nitrogen in the soil. Nitrogen is an important
element for optimal strawberry growth.
3. Add a layer of straw mulch around strawberry plants as
they start to grow; this mulch helps keep the fruit clean
once it grows and cuts down on weed growth. Pine needles
also increase acidity in the soil, which is beneficial to
strawberry growth.
4. Fertilize the soil around strawberry plants again if leaves
appear light green or unhealthy.

TIPS

1. Prepare soil a month in advance of planting, if possible, by

mixing in at least 1 inch of compost, decaying plant matter
such as dead leaves, and blood or bone meal.
2. Maintain strawberry plots for no more than three years at a
time; beyond that, the plants are susceptible to disease.
Start with a fresh planting in another area.
3. A liquid seaweed-based fertilizer can be applied during the
growing season to boost growth.

Warnings

• Avoid planting strawberries where they have been grown

previously or where eggplant, tomatoes or raspberries have
grown, to help prevent disease. Wait at least three years
before replanting strawberries in these areas.
• Do not fertilize plants that are bearing fruit or flowering, as
it may damage them. Avoid over-fertilizing as well, as this
encourages extra leaf growth, resulting in less fruit.

The second strategy of an organic strawberry cultivation is to

develop a habit of diligence when it comes to pulling weeds.
Hand-pulling is the first resort of most non-chemical growers.
Shallow cultivation can also be successfully utilized. There are a
34
number of such as organic herbicide labeled for use with growing
strawberries called Green-Match Ex and bio-pesticides like
Serenade, but they must be used in combination with other
physical methods. While virtually impossible to completely
eradicate even with conventional methods, strawberry pathogens
can also be deterred by the use of diatomaceous earth.

Developing a schedule of weeding and sticking to it is important in

the fight against unwanted growth. It is absolutely essential to
control weeds if you plan to maximize on fruit output.

Prepare a weed-free site that gets 8 to 10 hours of strong sunlight

per day, and add well-drained soil with a pH between 6 and 6.2. To
avoid verticillium wilt, don't plant in sites where raspberries,
cherry tomatoes, peppers, eggplants, or past strawberries have
grown before.

Maintain all the good agricultural practices and strawberry

preferences as summarized below:

Plant only disease-free, healthy plants in soils with good drainage

and air circulation. Avoid areas of poor drainage, mostly ensured
through raised beds. Keep your plantings away from areas that
may harbor large populations of mites or microbes detrimental to
your strawberries. Managing weeds is also important as they can
provide habitat for and harbor problem organisms as well.

Lots of sunlight and rich soil. Strawberries need a minimum of six

hours of sun exposure per day. Soil that is high in organic matter is
absolutely necessary as well. Strawberries also prefer slightly
acidic soil with a pH between 5.5 and 6.5. Test your soil for pH,
and then amend it if needed to raise its acidity level

Mulching heavily underneath the leaves of your plants is also

important. Soil, by its very nature, is home to legions of
microbes. In many strawberry plantings, rain droplets splashing
into dirt and thereby sending droplets of pathogen-infected wet

35
mud up onto the vegetative components are the cause of disease
and death. A heavy layer of mulch avoids this common problem.

Fungi species and many parasites find happy homes in the dead or
decaying leaves that fall from strawberry plants over the course of
their lives. Being vigilant to remove any dead or decaying plant
matter from your beds will help minimize problems.

The third option is the variety selection. Be sure to select a variety

that has at least some resistance to powdery mildew and
Verticillium wilt. The other main pests of strawberries are slugs
and snails. To keep them away, the best thing to do is install
copper edging around the perimeter of your bed. Slugs and snails
won't cross copper because it creates an electric reaction when it
comes into contact with their slime. Bird netting or fencing of
some sort is also a good idea to keep out the bigger pests like
squirrels, birds, and rabbits.

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 14. Disease and Insect Control

Strawberries are subject to attack by fungus diseases, such as root

rots and gray mold, and several types of insects, including
tarnished plant bugs and strawberry bud weevils, but many
problems can be prevented with proper planning and care. Plant
varieties that are resistant to red stele and Verticillium root rots.
Discourage insect pests by keeping the planting weed-free. Prevent
gray mold by keeping the plant rows narrow to improve air
circulation and mulching between rows.

14.1 Strawberry Pests

The following are common species of pests known to attack

strawberries.

• Aphids - A well known pest insect that can quickly settle

into soft tissue and damage the plant by sucking sap from
just below the leaves. Symptoms include clusters of aphids
at plants tips or on the undersides of leaves. In severe cases
the plant may begin to wither.

They are managed quite easily by sprays of Malathion

and dimethoate. Applying soapy water to plants or
releasing lady bugs into the garden can help with aphid
infestation.

• Birds - Birds, especially pigeons, can cause an array of

problems including eating seedlings, buds, leaves, fruit and
vegetables.

Can be easily be controlled covering the area with nets

on all sides, or simply SB green houses.

37
• Crown Borer - Adults are small, brownish red snouted
beetles that feed on foliage and berries. Larvae are little,
white, legless grubs that tunnel through the crowns. Short
of using chemicals, infected beds must be destroyed. When
replanting, keep at least 300 feet away from original site.
• Cut Worms - Fleshy green to black striped worms.

The cut worms can be controlled by dusting the soil

before planting with 5 per cent chlordane or Heptachlor
dust at the rate of 50 kg per hectare and mixing it
thoroughly in the soil by cultivator.

Cardboard collars can be used to keep the worms from

getting to the plants. Also mothballs or blood meal can
be spread around the bed. Digging up the ground in
early spring will help to expose and kill cut worms.

• Spider Mites - Barely visible white, green or brown mites

that feed at the base of plants on leaves and flowers. Mites
can be a nuisance in dry weather. Irrigation can, therefore,
be a control measure. Affected plants are stunted and yield
poorly.

The mites can be controlled with 0.05 per cent

Monocrotophos + 0.25 per cent wetablesulphur.
Spraying the plant forcefully with water, ensuring to
spray the undersides of leaves may help to rid this pest.
Spray with Kelthane and other appropriate pesticides
(acaricides) are advised in dry seasons.

• Nematodes - Severe in sandy soils than in clay with high

organic matter content. Several types exists like the lesion
nematodes (Pratylenchus spp), which attacks roots causing
amber to dark-brown spots. In severe cases, the roots rot.

A bud nematode (Aphelenchoides spp) that causes what

is called red plant as it lives and feeds among the
developing leaves.
38
 Use nematode-free plants, practice crop rotation and
soil fumigation to curb the pest.

• Slugs and Snails - Slime trails and irregular holes in fruits

are evidence of slugs and/or snails. Use straw as a mulch
to serve as a barrier between your plant and the wet soil.
Also you can try putting stale beer in pie plates and setting
them in the strawberry patch. Slugs will crawl in and
drown.

• Wire worms - are the larvae of the click beetle. They are
also known as click beetle because of their yellowish
brown color. They eat themselves into the rhizome of the
strawberry plant, as a result of which the strawberry plant
will start to become slack.

• Tarnished plant bug or lygus bug: The adult is coppery

brown with piercing and sucking mouth parts.

The bugs feed on achenes. The stink bug may also

damage the berries causing uneven ripening.

Sprays with diazinon, Malathion or dimethoate.

14.2 Strawberry Diseases

The most common diseases of strawberry plants include powdery

mildew, leaf spot, leaf blight, slime molds, red stele, verticillium
wilt, black root rot, nematodes, gray mold, rhizopus rot, and
leather rot. If symptoms such as powdery spots or brownish red
spots on leaves, curled leaves, rotten spots on fruits or decreased
yields are detected, remove all infected plant matter as soon as
possible; preferably when the plant is dry.

39
Powdery Mildew: Appears as a white powdery deposit over the
leaf surface and leaves become stunted and shrivel.

Remedy: Keep the soil moist and grow in cooler locations.

Grey Mould: You will see fuzzy grey mould on affected buds,
leaves, flowers or fruit. Infected plant parts eventually shrivel and
die. Grey mould is encouraged by overcrowding, so make sure you
plant your splits at the appropriate distance apart. Hygiene is very
important in preventing the spread of grey mould.

Remedy: If detected, remove the infected material and destroy.

40
Fungal Leaf Spot: Irregular purple/brown spots surrounded by a
yellow ring- the spotting spreads throughout the foliage especially
in warm, humid conditions. The plant weakens when the infection
is severe.

Remedy: Remove affected leaves and ventilate covered crops.

Leathery Rot
The fungus penetrates into the plant at the moment when there are
wounds. The root neck of the affected plants shows a reddish
brown discoloration. The plants will wilt and dies.

Remedy: Use healthy planting material and/or use resistant

varieties.

Red Root Rot

An affected plant will form no or only few flowers. The small

fruits will dry out.

41
Remedy: Use certified planting material.

Blossom-end Rot and Stem Rot.

This fungus occurs especially in long-range crops. In an early stage
small brown spots can arise on the buds. After the flowering the
calyx tails turn brown, the fruits discolor brown and dry.

Remedy: Keep the growing environment green

42
 15. Strawberry Harvesting

Harvesting of strawberry fruits starts 2½ months -3months after

planting. Harvesting seasons come 2-3 times per year. During the
harvesting season, pick every 2-3 days. The lifespan of the crop is
3 years.

A great increase in the number of ripe fruit occurs over the first 4
to 6 days of harvest. Berries are harvested every other day under
normal temperatures for about 6 to 7 pickings. Avoid picking the
fruit when plants are wet. Keep harvested berries out of the sun
and place them under refrigeration as soon as possible. Hand-pick
berries daily if possible and picks all berries that are ripe. Pick
berries when they are fully colored for optimal size and flavor.
Berries do not improve in quality after picking.

Toss out all moldy berries. This will help prevent rots from
spreading. Grading and packing often takes place in the field,
rather than in a processing facility.

The average picker can harvest 10 kg (12 to 15 pounds) per hour

over the entire season. Under excellent conditions, up to 175 kg in
a 10 hour day may be harvested by the average picker.

43
 16. Post harvest managements

Pack house practices

Sorting - done in the field and involves the removal of damaged
and misshapen and dirty fruits. Remove all the fruits without a
calyx.
Pre - cooling; this is done to remove the field heat, to minimize
deterioration. At small holder level, farmers can use charcoal
coolers. For distance markets, forced air pre-cooling will be
necessary.

Grading;
The fruits are graded into different sizes for marketing.
According to the shape and the size
1st grade: 6 - 9 fruits per punnet.
2nd grade: 15 - 25 fruits per punnet
3rd grade: 28 - 32 fruits per punnet
under sizes can be processed into jam or juice.

Packaging:

Strawberries are packed into the pun nets in readiness for the
market.
NB: avoid washing the fruits in the pack house since it destroys
the skin and hastens deterioration.

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 17. Market for Strawberry

Companies like trufood, zesta, Brookside, KCC among others are

importing these strawberries to use in their daily production needs
with outlets such as supermarkets and hotels requesting for more of
them day in day out. It is crystal clear that there is demand for this
sweet soft red fruit of Fragaria genus here in Kenya. Why are
these companies importing? This is simply because we cannot
produce enough ourselves. Very few farmers in Kenya have
embraced strawberry production and they have been smiling all the
way to the bank on weekly basis, others talk of daily basis.

Normally, the safest way is to concentrate where the first market

would be the consumers in surrounding towns and processing
companies. The direct community would be a good place to start
marketing your strawberries. This way, a farmer is always assured
of a place to sell his produce. Local fruit stores, restaurants and
other small users such as cake makers are also good buyers of
strawberries in Kenya. Industries which produce food flavors,
natural flavored yoghurt, jam etc also buy strawberries

Step 1: Look For Market Early Enough

But because the fruits are highly perishable (stays fresh for 4-5
days after harvesting).

It is advisable to start looking for market early enough to avoid

incurring losses.

Demand is readily available in major urban markets especially

among green-grocery suppliers. You can also access a larger
market by marketing to companies like Brookside, Trufood, KCC
and major supermarket chains. In that case, you will require
investing in good packaging and getting accreditation from The
Kenya Bureau of Standards.
45
Step 2: Harvesting and Selling Your Produce

Strawberries are highly perishable and hence a great deal of care in

harvesting and handling as well as its marketing also requires to be
organized carefully. Usually the fruit is picked in the early
morning and sent to the market in the afternoon of the same day or
is picked in the late afternoon, stored overnight in a cool place, and
sent to market the following morning.

For local market the fruit should be harvested when fully ripe, but
for transport to distant markets, it should be harvested when still
firm and before color has developed fully all over the fruit.
Harvesting should be done preferably daily. Since fruit is highly
perishable, it is packed in flat shallow containers of various types
(cardboard, bamboo, paper trays etc.) with one or two layers of
fruits. Harvesting should be done early in the morning in dry
conditions. Washing the fruit bruises it and spoils its luster.
Harvesting It is important to practice proper “picking hygiene”
46
when harvesting berries as disease can be easily spread if good
fruit is handled after bad fruit. Always wash hands after removing
moldy, deformed or over-ripe fruit and before harvesting your
good berries.

Pick every two to three days in mild climates or daily in very hot
weather and keep the green caps attached to each berry. In order to
preserve flavor and shelf life if you don't plan on eating your
harvest right away, pick into a shallow, paper towel lined
container, no more than three or four layers of berries deep.

Pick ripe strawberries by pinching through the stem above the

fruit.

Never pull on the berry itself. All strawberries will last several
days under refrigeration

47
 18. Financial Gains and Cost Benefit Analysis

A 1/8th piece of land can produce between 30kg and 50kg of

strawberries per week.

It is possible to recover your initial investment (or break-even)

within just 6 months of starting the farm!

The yield varies according to season and locality. A yield of 20 to

25 tons per hectare is excellent, though yields up to 50 tons per
hectare have been

For the purpose of calculating cost benefit analysis of

strawberry, we take 1/8 of acre, which is common with farmers.

Cost of Production/Year

The table below provides itemized cost of

production.

Operations Units quantity Price/unit Total Cost

Land preparations Tractor Hours 1 500 500
Ridge making Labor days 2 300 600
Soil sampling -
Transportation -
Transplanting Labor days 3 300 900
DAP kg 20 40 800
Urea kg 20 40 800
Farm yard manure Pick-up 1 2000 2000
Hoeing Labor days 18 300 4500
Insecticide/pesticide liters 1 2000 2000
Harvesting Labor days 48 300 13800
Packing crates 3 440 1320
Transporting KM 100 30 3000
Sprits number 2250 20 45000
Total cost 75220

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 Revenue stream
Item No of Volume/week Total Sales/kg Total
harvest volume revenue
Weekly Harvest/year 52 35kg 1820kg 110 200,200
Total revenue 200,200

Net revenues

Total cost 75220

Total revenue 200200
Net revenue 124980

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 19. Nutrition Value of Strawberry

Strawberries are very juicy health-packed fruits which can be eaten

whole, made into fruit salads, ice cream, jam, milk shake and
smoothie juice.

The following table shows the nutritive value of a serving

(147 g) of edible strawberries.

Energy 45 Vitamin A 45 IU
Protein 1.0 g Vitamin C 94 mg
Fat 0.0 g Niacin (Vitamin 540 mcg
B3)
Carbohydrate 11 g Foliate 2929.38 mcg
Dietary fiber 2.0 g Manganese 540 mcg
Calcium 23.2 mg Iron 0.6 mg
Magnesium 16.6 mg Selenium 1.16 mg
Potassium 170 mg Zinc 0.0 mg
Phosphorous 31.5 mg Sodium 0mg

50