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Horticulture and Home Pest News
Horticulture & Home Pest News is filled with articles on current horticulture, plant care, pest management, and common household pests written by Iowa State University Extension specialists in the Departments of Entomology, Horticulture and Plant Pathology.

Fall is for Bulb Planting

This article was published originally on 9/15/2010

As the fall gardening season winds down, many gardeners begin to slow with the dropping temperature. However, doing a little more digging can result in a beautiful payoff come spring. Now is a good time to plant spring flowering bulbs like daffodils or tulips. Once the first crocus blooms, the memory of this weary fall-time task will melt away.  
 
Then, every February some gardeners ask, "Is there any way I can plant the daffodils I've had in my basement all winter and get them to bloom next month?" Unfortunately the answer is no. The spring flowering bulbs we plant in Iowa have evolved to require a certain amount of cooling before they emerge and bloom. The technical term for the cooling requirement is vernalization. This evolutionary defense prevents plants from being tricked into flower during a mid-winter warm snap, after which they would certainly freeze as the winter weather inevitably returns. 
 
Planting bulbs in September and October when the soil is still relatively warm encourages the bulbs to grow roots. This means the plant will be able to spend more energy come spring on the beautiful blooms we enjoy. Another benefit to planting bulbs this early in the autumn is selection. Bulbs are not picked over yet so you can choose the best varieties. 
 
Want to plant more than the perennial favorites, tulips and daffodils? See the Horticulture and Home Pest News from August 24, 2005.  
 
Also see HHPN from August 12, 2009 for a list of spring flowering bulb catalogs. 
 
Plant bulbs as soon as possible after you purchase them. The planting depth and plant spacing for bulbs varies with the species. The rule of thumb is to plant to a depth that is 2 1/2 to 3 times the bulb's largest diameter.  See HHPN from September 12, 2002 for a table of bulb planting depths and spacings. 
 
While you're at your local garden center, don't forget to check the discounted prices on perennials, trees and shrubs. Just like bulbs, these plants can be planted in the fall so their roots become established before spring. Trees and shrubs planted in late summer or fall should be watered every 7 to 10 days during dry weather. Continue watering until the ground freezes.