Excerpted from the book Bulbs
by Lewis and Nancy Hill
A dormant bulb with its unattractive drab wrapping is somewhat like a chrysalis, the hard-shelled pupa of a butterfly. In time, and with the proper conditions, a beautiful flower will emerge, just as the butterfly comes from the chrysalis. Fortunately, bulbs are tough objects in their dormant stage, but even so, if they are to fulfill their potential, we must handle them properly.
Most dormant spring-blooming bulbs we buy in late summer or fall originated from little bulblets that grew around "parent" bulbs in a nursery. Propagators have painstakingly cared for them with what amounts to force feeding, then dug, graded, and shipped the bulbs so they reach us at the proper time for fall planting.
When you plant bulbs in early autumn, small feeder roots grow from their bases in soil that is still warm from summers heat. If newly planted bulbs are to bloom their best in the spring, feeder roots must grow before freezing weather arrives, which can vary from mid-September in the North to early November in southern regions. If you live where cool fall weather arrives late, dont plant your new spring bulbs too early in the fall, hoping to get better rooting. They may decide that their summer resting period is over, and, feeling warm earth around them, begin to grow. (Bulbs that stay in the ground all summer know better than to do this.) If in doubt, a good rule is to plant them about six weeks before the ground is likely to begin to freeze at night where you live. If you guessed wrong and notice some sprouts coming from your newly planted bulbs, pile a thin layer of compost over them, or after a cool night cover the bed with leaves or evergreen boughs to darken the soil and keep them cool. Hopefully, with that treatment they will reconsider their early awakening.
If you plant spring bulbs so late in the fall that they have no chance to grow the roots they need to absorb moisture and nutrients, they will probably bloom anyway, using the stored energy of the bulb. The flowers are not likely to be as nice as they would have been if they had faced spring with a better root system, however, although they should recover and bloom well in future years.
When you must plant spring bulbs late, you may be able to give them extra rooting time by spreading a thick mulch over them to keep the ground from chilling for a few extra weeks. Dont forget to take most of it off in very early spring, so the plants wont need to struggle through it.
After the bulbs have been planted, they need a period of chilling, which nature provides during the winter months in temperate climates. Spring bulbs can tolerate freezing temperatures, but they dont need them as long as the temperature stays as cool as 32° to 40° F for six or eight weeks. Like lilacs and other cool-weather plants, spring bulbs need this chilling period to survive and will not bloom well in areas that are frost-free unless they are chilled artificially.
As winter draws to a close and temperatures become warmer, leaves and buds begin to grow from the bulbs. Eager snowdrops are first to break their dormancy and push through the snow, followed by crocuses, narcissus, hyacinths, and tulips. We are always surprised when the sprouts pop through the ground as soon as it thaws and the weather warms, but are alarmed when cold days return and snow covers the budding plants. Fortunately, the plants go on growing as if they didnt mind this weather change a bit. They are certainly our kind of flower.
The list of hardy and tender bulbous plants that can brighten our summer months is a long one. Some such as lilies and irises will survive when left in the ground all year, as long as they are hardy in your planting zone. It is safe to plant the winter-hardy kinds in either spring or fall, or to buy them as potted plants and set them out anytime, even when in bloom.
The tender kinds such as dahlias and gladioli, which originated in tropical climates, cant tolerate freezing temperatures, so you must either treat them as annuals and replace them each spring or dig up the roots in the fall and store them over the winter.
Plant the fall-blooming bulbs, such as autumn crocus and lycoris, early in the spring before they start to grow or anytime throughout the summer, when they are dormant. Follow the instructions you receive with the bulbs.
You can move bulbs within your garden safely even when they are in bloom if you take a large clump of soil with them. If you want to break the bulbs apart to extend your plantings, however, wait until they are dormant.
Before planting your bulbs, keep them in a dry, dark, cool place in a paper bag or open container rather than in an airtight can or plastic bag. They need air circulation so they dont collect moisture and rot.
from Bulbs by Lewis & Nancy Hill
When bulbs arrive too late to plant outdoors, you can often salvage them by potting and forcing them for late winter blooms indoors. Occasionally, however, this advice wont work. Authors Lewis & Nancy Hill remember when friends once called to say, "We just realized that we havent planted the 200 daffodil bulbs that came in September. Got any ideas?" Obviously they had too many to pot, so the Hills suggested they plant the bulbs close together -- top side up -- in deep flats of potting soil, put them in a cold root cellar or cold frame for the winter, and set them out in the spring as early as they could dig in the ground.
The friends reported that the bulbs did bloom after they planted them out in the spring, although not as well as they would have otherwise. The next year they bloomed beautifully, however, so all was not lost. Narcissus, crocuses, and the smaller bulbs are more likely to survive this treatment than tulips and hyacinths.
Another gardening friend of the Hills was ill one fall and left her tulip bulbs in a bag in an unheated garage. In early spring, as soon as the ground thawed, she soaked them in water overnight and then planted them at the recommended depth. Every one survived and produced foliage, and many of them bloomed. It just goes to show that bulbs are often more resilient than we think.