FAQs About Spring Blooming Bulbs

Barbara Mrgich
Adams County Master Gardener

Most of your earliest spring garden color can come from bulbs. If you enjoy seeing active growth as early as March (and sometimes, even February), now is the time to plan and plant. Hopefully, any questions you have will be answered here.

What is a bulb? A bulb is a swollen stem that stores nutrients for its plant. A true bulb contains all the flower parts. Rhizomes, corms, and tubers are sometimes referred to as bulbs, but they do not contain all the flower parts. They do, however, store all the nutrients their flower will need, and are usually handled pretty much the same as bulbs.

What are some common bulbs? Daffodils, tulips, hyacinths, grape hyacinths and alliums are true bulbs. Gladioli and crocuses are examples of corms. Irises are rhizomes. While bulbs and corms are planted fairly deep in the soil, rhizomes like to lie just under the soil surface.

Why should I plant my bulbs in the fall? The spring-flowering bulbs all need about 14 to 16 weeks of cold weather before they will bloom. Our zone 6 climate is perfect for bulbs. People in warmer climates don't have the success we have because their winters are not cold for long enough.

What are the soil requirements for bulbs? Well drained soil is a must. Bulbs will rot if left to lie in soggy soil. Bulbs also require plenty of sun. They prefer a neutral ph and lots of organic matter.

Will bulbs grow in clay soil? Clay actually has plenty of nutrients. However, it holds water, and does not allow good drainage or oxygen circulation. The solution is lots of organic matter mixed into the clay.

How do i know which end is up when planting bulbs? Most bulbs are rather flat on the bottom and pointy on the top. Sometimes you can see the remains of dried roots. The pointed side, where the flower stem will emerge, should point up. When you start trying out some of the smaller, less familiar bulbs, you may find some that are rather shapeless. It's impossible to tell the top from the bottom, and, luckily, it doesn't matter.

If you should plant a bulb upside-down the stem will usually wrap around and come up anyway. Fritillaria, or crown imperials, have a very large flat bulb that is very prone to rot because its flat surface collects and holds moisture. The solution is to deliberately plant the bulb on its side.

Should I fertilize my bulbs? Fertilizing your bulbs once a year just after they bloom with a good organic fertilizer will help to insure large blooms that continue year after year. If you incorporate plenty of compost and other organic matter into your soil, commercial fertilizer may not be necessary. Daffodils are especially self-sufficient. Tulips are especially needy. Most other bulbs lie somewhere in between.

Why do I sometimes find bulbs that i previously planted several inches deep up on the soil surface? Alternate freezing and thawing of the soil during the winter can cause bulbs and other plants to get pushed up out of the soil. This is called heaving. Planting your bulbs deeper than recommended is a good solution for heaving. If you realize that your bulbs have heaved to the soil surface, dig them up and replant them at the correct depth.

When can I transplant my bulbs? When a previously sunny spot is now too shady, or overcrowding prevents blooming, then transplanting becomes necessary. The ideal time to move bulbs is in the fall, but unless you have meticulously marked their location, they are very difficult to locate, and it's easy to end up slicing them in half.

Bulbs can be moved in the spring, with very good success. Wait until they have finished blooming and their leaves are pretty far gone, but you can still see them. Then relocate them keeping the tops intact.

Why do I have to let the leaves wither and die before I can cut them off? When the bulb is ready to bloom, it nourishes the stem, leaves and flower with the nutrients from within. When the flower is spent, you should cut off the flower so the bulb does not waste energy on seed production. Removing the green leaves, however, robs the plant of the chance to perform photosynthesis by which the plant converts sunlight to energy to make next year's flowers. Cutting them off prematurely will slowly weaken the bulb until it finally fails bloom.

What can i do to hide the withering leaves of bulbs during late May and June? The challenge is to find plants that emerge later, or at least remain small while the bulbs are blooming, then put on fast growth to hide the browning bulb leaves. In the shade, hostas and ferns work well. In the sun, two suggestions i especially like are nepeta 'walker's low' and verbena 'homestead purple'.

Where should I buy bulbs? For the best possible selection, unusual bulbs, and the greatest variety of the lesser known bulbs, go to the catalogs. They will not only have the largest selections, they will give you great horticulture tips and do a very good job of answering any questions if you call them. They also make it easy to have a continuous display throughout the season by offering, early spring, mid spring, and late blooming bulb varieties that you may not find elsewhere. Now is the time to order for planting this fall. If you don't have a favorite, simply do a Google search on bulb catalogs for a starter list of suggestions.

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