Why you shouldn’t plant spring bulbs too early in Western New York

by Connie Oswald Stofko

“While the big box stores have bulbs available before Labor Day, bulbs should not be planted before the beginning of October,” said Patti Jablonski-Dopkin, general manager at Urban Roots Cooperative Garden Market. “Our bulb suppliers won’t send them till the end of September. We usually have them in stock by the first week in October.”

Autumn is the time to plant bulbs that flower in spring, but planting them too early could damage or even kill them.

When you plant spring-flowering bulbs, the soil needs to be cool; around 55 degrees Fahrenheit, she explained. Cool soil tells the bulb to grow roots, which is what you want. The bulb is getting established for spring, when it will send out leaves and a flower.

If the soil is too warm, it tells the bulb to start producing flowers right away, and you don’t want that.

“You’re not going to get flowers in spring” if the bulb is planted when the soil is too warm, she said. If the bulb sends up foliage too early, the leaves could be damaged by a killing frost or a lot of snow. It might even kill the entire bulb.

If you want to force your bulbs (have them flower inside before they would flower outside), it’s still too early–unless you have a refrigerator with no food in it, Jablonski-Dopkin said.

Bulbs need to go through a period with cold temperatures, between 35 and 48 degrees Fahrenheit. In October, you can keep your pots containing bulbs in a cold cellar or an unheated garage. Right now, your basement and garage are probably too warm.

A refrigerator would work–if you don’t have food in it, she said. Fruits and vegetables naturally give off ethylene gas, which can damage spring bulbs (with the exception of some varieties of tulips). Ethylene gas can cause poor rooting, a shorter stem on the plant and flowering too soon. It can even kill the embryonic flower in the bulb.

While there are some tulips that aren’t as susceptible to ethylene, “I wouldn’t take the chance,” Jablonski-Dopkin said.

One workaround might be to “Take half the beers out of your husband’s beer refrigerator,” she suggested with a laugh.

As we get closer to October, we’ll bring you more information on how to plant spring bulbs outside and how to force them to bloom inside.