Although so many familiar flowering bulbs bloom in the spring, they need to be planted months earlier, if they are to bloom. The general rule is that spring-blooming bulbs are planted in the fall, but does that mean anytime in the fall is okay to start planting?
The Ideal Time to Plant Spring-Blooming Bulbs
There is no perfect moment, calendar-wise, for planting bulbs. The ideal time to plant your spring bulbs depends on where you live and what the weather is like that season.
Bulbs need several weeks in the ground to get their root systems growing before the ground freezes. However, you don’t want to plant them so early in the season that they have time to sprout. Sending up leaves will deplete some of the energy stored in the bulb, which it needs to get it through the winter. So if you’re having a long Indian Summer, hold off planting. But in general:
- Gardeners in the coldest Zones (1 - 4) should plant their bulbs in late August and September. Don't wait for the calendar to say it is officially fall.
- Gardeners in Zones 4 - 7 can't trust the calendar either. Wait until the temperatures start to dip, especially during the day. That may be September, in some years, later in others. It's better to err on the later side. You can continue planting into November and beyond if the ground has not frozen.
- Bulbs planted in the warmest climates obviously are not going to get a chilling period, so these rules don't apply. You may need to purchase pre-chilled bulbs, for the best success.
What to do if You Forget to Plant in the Fall
The guidelines mentioned above are ideal planting times, but sooner or later every gardener buys bulbs and then forgets about them or doesn’t get around to planting. Take heart, all is not lost.
Most bulbs on the shelves were dug early in the summer and then stored for shipping. As long as they are plump and firm, they’re good to go. The important thing is to get your bulbs planted in soil as soon as possible. Storing them out of soil all winter will cause them to wither and die.
Plus, to break dormancy and bloom, most spring-blooming bulbs need to be exposed to a good 12 -14 weeks of chilling temperatures below 45 degrees F.
- Before the Ground Freezes The old adage says that “As long as you can get your shovel in the ground, you can plant your bulbs.” It’s hard to believe, but they are better off in frosty soil than they’d be sitting in your garage or basement. Spring bulbs have been known to send out roots in soil that’s just above freezing. So if you’re planting late in the season, try and plant as deeply as possible, even a few inches deeper than recommended, for the added insulation. Once the ground freezes hard, mulch the bulbs with a few inches of leaves, straw or some evergreen boughs. It might take longer for the shoots to surface from the extra depth in the spring, but eventually, they will.
- After the Ground Has Frozen Solid Once the ground has frozen and you can no longer dig, you might be tempted to toss your bulbs into a dark corner of the basement and forget about them until spring. But spring-blooming bulbs are not like dahlias, gladioli, or other summer-blooming tender bulbs that can be stored away for winter. Remember, spring-blooming bulbs need to grow some roots and experience a period of chilling, in order to be able to sprout and flower next season. They only have enough energy stored to get them through one dormant season. They need to grow next year to replenish themselves, so you really need to get them into soil somehow. Here are two options that have worked for other gardeners in this predicament:
- Pot them up. Plant them in large containers with potting soil. Make sure the bulbs are not right up against the sides of the pot, where they could freeze. There should be plenty of soil between the pot sides and the bulbs, for insulation. Then you can store the pot in an unheated garage, porch or even a basement window well. You want them to get cold, but not expose them to extremes.
You’ll need to water the pot once a month or so, as it dries out. Don’t allow the soil to remain wet. Move the pot outside in mid-spring and either let the bulbs bloom in the pot or transplant them into your garden, once they have sprouted. Transplanting will give the bulbs more time to establish themselves in the garden and become stronger.
- If you can’t dig into the soil, plant on top of it. Spread your bulbs out and then top them with at least 6 - 8 inches of potting soil. It helps to circle the area with chicken wire or hardware cloth. The wire will hold the soil in place and deter rodents that will be tempted to make a meal of your bulbs. You can remove it in the spring. Mulch the mound, once it freezes hard.
Obviously planting your spring-blooming bulbs on time is the best guarantee of spring blooms. But even if the bulbs you planted late don’t put on much of a show the first year, they should get better with age.