Spring-flowering bulbs must be planted in the fall because they require a sustained "dormant" period of cold temperatures to stimulate root development.
As a rule, the colder your climate, the earlier you plant. In colder northern climates, for example, plant in September or October. In warmer climates you may need to plant bulbs in December (or even later). The only universal rule is that, spring-flowering bulbs must be planted before the first hard frost.
It's best to plant bulbs as soon as possible after bringing them home. If you must store them, keep them dry and cool between 50° and 60° (F). For long storage periods, a refrigerator vegetable compartment can be used, but be sure to keep them away from ripening fruit. The gas emitted by fruit's ripening process can destroy bulbs.
Most spring-flowering Dutch bulbs will thrive in either full or partial sun, but do just fine in almost any location that offers good drainage. Bulbs will rot in standing water so avoid areas prone to flooding, such as the bottom of hills or under drainpipes.
After choosing the site:
- Dig either a trench for a bed planting, or individual holes for individual bulbs or small cluster of bulbs. (Note that a cluster of flowers is more striking to the eye than a lone bloomer.) To determine how deep to plant, consider the caliber or size of the bulb. Large bulbs (2 inches or more) are usually planted about 8 inches deep; smaller-size bulbs (1 inch) are planted 5 inches deep.
- Loosen the soil with a rake to aerate it and remove any weeds and small stones. Mix in a bit of peat moss to improve soil drainage. Place do not push bulbs firmly in the soil with the pointed side up. Space large bulbs 3-10 inches apart and small bulbs 1-2 inches apart. (If you're not sure which end is right-side-up, don't worry. Upside-down bulbs usually come up anyway!)
- Cover the bulbs with soil and water generously. Add 2-3 inches of mulch, pine bark is fine, on top of the garden bed. This will provide added protection from the cold and keeps the soil from drying out.
At fall planting time:
- for first year's bloom, no fertilizer is needed.
- for naturalized bulbs after the first season, there are three good options:
- a good organic compost or well-rotted cow manure worked into the soil when planting, and a mulch of this material,
- a slow-release bulb food,
- a combination of bone meal and an 8-8-8 or 10-10-10(NPK), fast-release soluble fertilizer (about one tablespoon per square foot).
- Again, for first year blooms, no fertilizer is needed.
- for naturalized plantings or perennializing plants, fertilizer considerations are:
- nothing further is needed if last fall you applied well-rotted cow manure or a slow release bulb food
- if you used bone meal and a fast-release fertilizer, you will want to apply a nitrogen-rich fast-release NPK fertilizer in the spring just as the shoots first emerge from the soil (which would be about 6 weeks prior to bloom).
- Plant low-growing bulbs, such as grape hyacinths, in front taller flowers, such as tulips,
- Always plant bulbs in groups, either in small clusters or large beds, a single flower standing alone is not very dramatic,
- Plant scattered clusters of early-flowering bulbs, such as crocus, throughout your lawn to achieve a "natural" look,
- Plant clusters of daffodils around the woodpile, or in a meadow area that is not mowed often. These will add a colorful accent to your landscape in spring and, if left on their own to wilt away, will return year after year. Well-selected and mature plantings of naturalized bulbs can add value to your home, just as mature trees and shrubs do,
- Experiment. You know better than the experts what flowers you fancy. Pick a flower bulb variety on a whim and try a small planting. If it does well for you, add more next year.