When Is It Too Late to Plant Spring Bulbs? Why You Shouldn't Wait Any Longer

Spring bulbs are not just ordinary plants. Their flowers, which bloom in various colors, are vibrant enough to breathe life into the drabbest flower border.

More importantly, many reappear just when the winter-weary most need color: early spring. They range in size from tall crown imperials (Fritillaria imperialis) to tiny snowdrops (Galanthus nivalis). They are typically planted in the fall, according to the USDA growing zone you live in.

But what happens if you forget to plant them then? Is all lost? How late is too late to plant spring bulbs?

When Is It Too Late to Plant Spring Bulbs?

The standard planting times for spring bulbs are as follows:

• Zones 2 to 3: September
• Zones 4 to 5: October
• Zones 6 to 7: November
• Zone 8: December
  

By getting your spring bulbs in the ground on time, you give them a chance to put down roots before the ground freezes. This gives them a head start when spring rolls around. So what happens if you miss the deadline (according to your zone)?

If you only miss the deadline by a month or so, it may not be too late. What you have to hope for is that the soil has not frozen yet (or that there is an extended thaw). If you can still work the soil, then you can still plant spring bulbs. Take tulip bulbs, for example. Typical planting advice is to install them at a depth of 6 to 8 inches; so you have to be able to work the soil down to that level.

There will likely be a delay in blooming, so that you will not have flowers in spring, but rather in summer. The delay will be caused by the temperature of the soil: It must be above 40 F for the roots of your spring bulbs to form properly.

Want more gardening tips? Sign up for our free gardening newsletter for our best-growing tips, troubleshooting hacks, and more!

Planting Bulbs in Winter for Later Spring Blooms

What if the soil is too frozen for you to dig down 6 to 8 inches to plant tulip bulbs? A Cornell study suggests how you can push the envelope further. An added benefit of planting tulips at a later date is that you can save them from catching fungal diseases (such as tulip fire) that thrive under warm, damp conditions:

• Work up the soil to a depth of 2 inches
• Install your tulip bulbs on top of that soil
• Apply a layer of mulch over the tulip bulbs (2 to 4 inches thick)
• Water the mulch until it is evenly moist (but avoid flooding it)

Best Plants for Winter Planting in the South

Planting spring bulbs in winter is much more feasible in the South. But not all types of spring bulbs thrive in the Southern climate. Here are some of the best choices:

• Daffodils: The daffodils with the big, trumpet-shaped flowers sometimes perform poorly in the South. Smaller-flowered types tend to do better, such as Tazetta hybrids, jonquil hybrids, and pheasant's eye (Narcissus poeticus).
• Crocus: Again, avoid the types with the bigger flowers. Examples of smaller-flowered kinds that thrive are cloth-of-gold (Crocus angustifolius) and snow crocus (Crocus chrysanthus).
  
• Alliums: Recommended "flowering onions" for the South include the Naples onion (Allium neopolitanum) and the star of Persia onion (Allium christophii).
  

Tips for Planting Bulbs in Winter

There are a number of things you can do to increase your chances of success in planting spring bulbs in winter, beyond following standard practice. These include:

• Bulb inspection, storage: Since spring bulbs planted in winter may be severely challenged, it is important to start with the best stock that you can. Inspect the bulbs carefully. If bacteria, fungi, or insect pests infest a bulb at some point, the bulb can become misshapen, signaling inferior quality. But touch the bulbs, too: bulbs that are squishy are no good. Once they have passed inspection, store the bulbs under the right conditions. The ideal location will be dry, dark, and cool (but not freezing).
• Plant the bulbs deeper: Plant the spring bulbs deeper than you normally would to afford them some extra protection from the elements.
• Mulch the bulbs: This will help keep the bulbs from becoming exposed during extreme freeze-thaw cycles.