Fall Planting (Spring Blooming)
Mother Nature works in marvelous ways and designed spring-flowering bulbs to withstand winter's cold. While the soil itself may freeze beyond the planting depth of the bulb, soil temperatures rarely fall below 29º F/-2ºC or 30º/-1ºC F. While these temperatures might freeze the water in the bulbs, it doesn't harm the actual cells in the bulb. In fact, the cells undergo a biochemical process that insulates the bulb to keep it safe and snug. Also, in the same way humans can stay warm in a "snow cave," the snow cover, along with a nice layer of mulch over the bulb bed, helps insulate the soil.
The earlier you can plant bulbs in fall, the better. Planting times vary, of course, depending on your hardiness zone. Bulbs need time to establish strong root systems before the winter frosts set in. Don't forget to water newly planted bulbs — it helps get the roots going! Once the cold arrives, bulbs enter a new cycle to prepare for spring blooming.
Tulips love both sun and shade. Remember, though, that tulips bloom in spring when there's a lot of sun because all the deciduous, non-evergreen trees in your yard have yet to leaf out.
Naturalized bulbs tend to bloom about two weeks later in subsequent years than they did their first year. So keep that in mind when choosing bulbs for "color combos." If you want to coordinate spring blooms or add new bulbs to an existing planting, don't forget to factor in the later bloom time.
Tulips, daffodils and other spring-flowering bulbs require a long period of cool temperatures to undergo the biochemical process that allows them to flower. So, in the fall get them in the ground ideally six weeks before hard freezes to give them the time they need to develop strong roots.
Wait six to eight weeks after flowering before mowing grass strips containing flower bulbs. You need to wait until all the aerial parts of the bulbs have withered back, since some bulbs such as Glory-of-the-snow, Squill and Winter aconite propagate by seed and their seeds need a chance to mature.
The Fritillaria imperialis bulbs I bought have a really bad smell. Is there something wrong with them?
Ah, the fragrant "stink lily" (at least, that's what the Dutch have nicknamed the Crown Imperial). Its skunky, old gym sock smell is a natural characteristic of the bulb and its flowers. Moles can't stand the smell of them either, which makes them the perfect deterrent for these destructive nuisances.