GB2104763A - Container for growing plants - Google Patents

Abstract

A growing bag comprising a solid plant growth medium contained in a container made from a flexible material, characterised in that the container is provided with one or more groups of apertures being permeable to air and water but substantially impermeable to the solid plant growth medium and an area without apertures where the growing bag is to be in contact with the ground. <IMAGE>

Description

SPECIFICATION Container The present invention relates to a container for a plant growth medium.

Over the past decade it has become widespread practice to grow plants, e.g. tomatoes, cucumbers, peppers and so on, in plastics sacks filled with a growth medium, notably a peat based compost. For convenience the term growing bag will be used herein to denote such sacks.

However, during the growth of plants in a growing bag it is necessary to water the growth medium, often by way of trickle feed irrigation. Excess water is often fed to the growing bag due to overwatering or inconsistencies in the outflow through the nozzles of the irrigation system. This forms a waterlogged layer of growth medium at the base of the bag as it lies on the ground. With a conventional oval cross-sectioned bag, this layer can comprise a comparatively large proportion of the contents of the bag. It has therefore been the common practice to slash a number of drainage slits along the side wall of the bag. Whilst this aids removal of some of the excess water, it introduces new problems as it may lead to the loss of some plant growth medium through the slits.In addition, plant roots are likely to grow through the drainage slits so that one of the main advantages of the growing bag, the isolation from disease of the plant growth medium and of the plants, is lost.

There have been proposals to form the growing bag so that it has a generally circular crosssection. This would have the result of reducing the proportion of the growing medium which remains waterlogged, but it is difficult to fill such a sack so that it retains its generally circular cross-section when laid flat on the ground. It has also been proposed to make the bag from a woven material, e.g. woven polypropylene. Such a construction leads to free drainage of excess water through the apertures in the bag wall formed by the openings in the woven fabric, but also permits the plant roots to grow through the bag wall, thus destroying the isolation of the growth medium and the plant roots from external disease.

We have now devised a form of growing bag which reduces the above problems and aids aeration of the growing medium during use.

Accordingly, the present invention provides a growing bag comprising a solid plant growth medium contained in a container made from a flexible material, characterised in that the container is provided with one or more groups of apertures which are permeable to air and water, but which are substantially impermeable to the solid plant growth medium, and an area without apertures where the growing bag is to be in contact with the ground.

Preferably the container is an elongated bag or sack in the shape of a bolster or pillow.

Preferably the container is of oval, rectangular or, most preferably, circular cross-section.

Preferably the container is a plastics (notably a polyalkylene or polyvinyl chloride) bag or sack.

Preferably there are at least two groups of apertures. In a particularly preferred form, the groups of apertures form two sets of longitudinal rows of apertures located from about 60d to 2700 apart circumferentially on the wall of the container.

To aid understanding of the invention, a preferred form thereof will now be described with reference to the accompanying drawings in which Figure 1 is a diagrammatic perspective view of a growing bag of the invention and Figure 2 is a transverse vertical cross-section through the bag of Figure 1.

The growing bag comprises a generally cylindrical container 1 and a plant growth medium therein. The container can be provided with internal shaping means to cause it to have a substantially circular cross-section. However, it is preferred to fill a conventional pillow or gussetted form of sack with sufficient of the plant growth medium to distend the sack so that it adopts a generally circular cross-section. Such filling can be carried out using conventional filling techniques and is made possible by the apertures in the container wall, which let air entrapped in the bag escape as the container is filled.

The container can be made from any suitable material, notably a polyethylene, and can be of any desired size. If desired, the container can carry markings 2 to show where one or more plant growth apertures are to be cut through the wall of the container for plants to grow in the medium in the bag. If desired, the container can be coloured, e.g. green, or black or white.

The wall of the container is provided with generally parallel longitudinal rows of apertures 3.

These rows are preferably located so that they will lie in the median arc of the container wall on each side when the growing bag is laid on the ground, i.e a in Figure 2 will have a value of from 60 to 2700. Typically, the rows will extend over an arc of from 5 to 900 preferably 5 to 450 of the circumference of the container and there are two such sets of rows separated by an arc (a in Figure 2) of unapertured wall of from 90 to 1750 Preferably, the rows of apertures are diametrically opposed.

The preponderance of the apertures have a maximum dimension of 5 mms, preferably less than 3 mms, in order to minimise escape of the contents of the container. Where the plant growth medium is in particulate form, e.g. a peat compost, the apertures preferably have a maximum diameter less than the average particle size of the plant growth medium. The apertures can be formed randomly in a longitudinal band along the container; or are formed in longitudinal rows at longitudinal intervals of from 1 to 5 times the maximum dimension of the aperture. Preferably, each set of rows contains from 2 to 20 rows and the apertures in adjacent rows are staggered.

The apertures can be formed by any appropriate method, e.g. by piercing the wall individually or collectively with piercing pins, by stamping out the appropriate dots from the wall material, by the use of hot pins, or by localised melting of the wall material. However, a preferred method is the use of a plurality of air jets during the extrusion of the container. A particularly preferred material for present use is that sold under the Trade Name of PerfoPak. If desired, the apertures can be sealed after forming (e.g. using a tear off adhesive strip) or the growing bag may be wrapped to form a sealed container for storage or transport prior to use.

It is also within the scope of the present invention to provide markings on the wall of a substantially imperforate container to indicate where the rows of apertures are to be formed, to fill that container with plant growth medium and subsequently to form the apertures in the container wall. Thus, the present invention provides a growing bag carrying markings on the wall thereof indicating where to, or in association with instructions as to how to, form a plurality of longitudinal rows of apertures through the wall thereof. The invention further provides a method for making a growing bag of the invention which comprises forming a plurality of longitudinal rows of apertures in a wall of an elongated container made from a flexible material and which contains a plant growth medium.

The container contains a plant growth medium.

This can be of any appropriate type, e.g. a formed plastics (e.g. a polyurethane or urealaldehyde condensation product); a peat compost, optionally containing other materials, e.g. vermiculite, expanded polystyrene beads, and/or perlite; rockwool; bark or other organic waste materials. A particularly preferred growth medium is a peat based compost sold by the Applicants under the Registered Trade Mark LEVINGTON. Typically, the container contains from 5 to 50 litres of growing medium.

As indicated above, the container can be filled with the growth medium using any appropriate technique. If desired the growth medium can be compressed, e.g by 10 to 20% of its original volume, so that the growth medium exerts a distending force on the container which will aid it to adopt a generally circular cross-section. As stated above, the presence of the rows of apertures we have found aids escape of air from the container and thus enables the container to be filled at an acceptable rate without the need to use special filling techniques.

Accordingly, the present invention also provides a method for making a growing bag which comprises filling a solid growing medium into a container as described above, e.g. an elongated flexible container having a plurality of generally parallel longitudinal rows of apertures through the wall of the container; and closing the container. We also provide a container as described above suitable for filling with a solid growing medium.

The invention also comprises a method of cultivating plants, which comprises utilising a container made from a flexible material containing a plant growth medium, characterised in that the container is provided with one or more groups of apertures being permeable to air and water but substantially impermeable to the solid plant growth medium and an area without apertures where the container is in contact with the ground.

The invention will now be illustrated, through not in any way limited, by the following examples: EXAMPLE 1 Cucumbers were grown in polyethylene growing bags filled with compost sold under the Registered Trade Mark LEVINGTON. The bags were provided with two longitudinal bands of oval apertures arranged along the median arcs of the container. Each band had a width of 60 mm and comprised eleven rows of apertures. The apertures were oval in shape and had maximum axes of from 1.0 to 3.0 mm. The distance between rows was 6.0 mm and in each row the hoies were 10.0 mm apart. The holes were produced by a plurality of air jets during the extrusion of tne container ano tne polyethylene material containing them was sold under the trade name of PERFOPAK.

Twenty-five growing bags with apertures, each planted with two cucumber plants, were used and compared with twenty-five control bags identical to them except that these contained no apertures.

Identical culture methods were used for each group.

Ten weeks after planting the yield from the growing bags with apertures was 14.11 kg/m2 whereas that from the control bags was 12.01 kg/m2, an increase in yield of 17.5%.

EXAMPLE 2 Tomatoes of the variety SONATINE were grown from seed and planted in growing bags with apertures and in control growing bags identical to those used in Example 1. Three tomato plants were grown in each bag and standard temperatures, carbon dioxide enrichment and pollination techniques were used throughout.

The seedlings were planted 10 2 weeks after sowing, and the first pick made 182 weeks after sowing. Harvesting continued until 28 weeks after sowing. The yield from the growing bags with apertures was greater than that from the control bags.

EXAMPLE 3 Tomatoes were also grown in growing bags with apertures (as described in Example 1) filled with sedge peat and in identical control bags with no apertures under identical conditions.

The yield for the growing bags with apertures was greater than that from the control bags.

Claims (1)

1. A growing bag comprising a solid plant growth medium contained in a container made from a flexible material, characterised in that the container is provided with one or more groups of apertures which are permeable to air and water, but which are substantially impermeable to the solid plant growth medium and an area without apertures where the growing bag is to be in contact with the ground.

2. A growing bag as claimed in Claim 1 in which the container is an elongated bag or sack in the shape of a bolster or pillow.

3. A growing bag as claimed in either of the preceding Claims in which the container has an oval cross-section.

4. A growing bag as claimed in Claim 1 or Claim 2 in which the container has a rectangular cross-section.

5. A growing bag as claimed in Claim 1 or Claim 2 in which the container has a circular cross-section.

6. A growing bag as claimed in any one of the preceding Claims in which the container is made of a plastics material.

7. A growing bag as claimed in any one of the preceding Claims in which the container is provided with two sets of longitudinal rows of apertures.

8. A growing bag as claimed in Claim 7 in which the two sets of longitudinal rows of apertures are located from 600 to 2700 apart circumferentially on the wall of the container.

9. A growing bag as claimed in any one of the preceding Claims in which the container is provided with two sets of longitudinal rows of apertures which are diametrically opposed.

10. A growing bag as claimed in any one of the.

preceding Claims in which the apertures through the wall of the container are formed by the use of a plurality of air jets during the extrusion of the container.

1 A container made from a flexible material and suitable for filling with a solid plant growth medium the container being provided with one or more groups of apertures which are permeable to air and water, but which are of such a size as to be substantially impermeable to the solid plant growth medium.

12. A container as claimed in Claim 11 in which the apertures are formed by the use of a plurality of air jets during the extrusion of the container.

13. A method for making a growing bag which comprises forming one or more groups of longitudinal rows of apertures being permeable to air and water but substantially impermeable to a solid plant growth medium in a wall of an elongated container made from a flexible material and which contains a solid plant growth medium.

14. A method for making a growing bag which comprises filling a solid plant growth medium into an elongated container made from a flexible material having one or more groups of apertures, which are permeable to air and water, but are substantially impermeable to a solid plant growth medium, through the container, and closing the container.

1 5. A method of cultivating plants which comprises utilising a container made from a flexible material containing a plant growth medium, characterised in that the container is provided with one or more groups of apertures which are permeable to air and water, but are substantially impermeable to the solid plant growth medium, and an area without apertures where the container is to be in contact with the ground.

1 6. A growing bag substantially as hereinbefore described with respect to the drawings.