Forcing Bulbs

Audrey Hillman
Adams County Master Gardener

Itís not nice to fool Mother Nature! Or that what weíve always been told, and in most cases I would have to agree. When you force bulbs you are indeed putting her to the test with just a poke in the ribs by irritating the changes that would be occurring outside if the bulb were planted. By making spring come early you can enjoy blooming daffodils, tulips and other bulbs inside in February.

Most spring blooming bulbs are dormant during the summer. As the soil cools in the fall the bulbs begin to send out new roots. This will continue until the ground freezes. As the ground warms in the spring the bulb comes to life and by using the roots it already has it can send up its flowers quickly. Each bulb requires a certain period of time to "chill before it blooms. Crocuses require the least amount of time and so are among the earliest spring bulbs to bloom. Dwarf Irises, like crocuses, require only about six weeks. Hyacinths prefer 12-15 weeks. Daffodils need at least 12 and are better with 16 weeks, as are tulips. So by starting a bulb's required chill time early, we can force them to bloom early. It is important to remember not to scrimp on their chill time.

If you would like to try your hand at forcing bulbs, start off with good healthy bulbs. Make sure they have no soft spots, or mold. Then choose your containers. Be sure that it has drainage holes. The worst enemy of bulbs is sopping wet soil. Put some small stones, gravel, or broken pot pieces in the bottom. You want to prevent the roots from coming out of the hole but not the water. Next consider your potting soil.

Remember bulbs come ready to go so your planting mix doesn't have to provide nutrients. But it is essential that it have good drainage. A mix of 60% peat, 20% vermiculite, and 20% perlite should do nicely. Dampen it before you begin potting. Add so until the pot is half full. Layer the bulbs in the pot as tightly as you like. Itís OK for them to touch. If you are planting tulips, place the flat edge of the bulb against the edge of the container. The flat side is where the first large leaf comes from and by placing them all to the outside you will create a uniform appearance to your arrangement. Most bulbs can take double layer in the pot, so at this point just add enough soil to cover all of the first layer of bulbs but the tips. Put the second layer of bulbs in the pot, being careful not to place them directly on top of the underlying bulbs. Then fill your container with soil to overflowing, and label it so you'll know what you've planted.

Next you need to decide where to put your bulbs to do their chill time. You can use a refrigerator set at 40 degrees but remember to keep them watered! Also be sure not to allow any fruit to ripen in the firg that has bulbs in it. The fruit releases ethylene gas, which is very toxic to bulbs. You can also dig a hole 18 inches deep, place the container in it, cover it with soil, and then a thick layer of mulch and leaves to keep the soil from freezing (so you can dig them up again). Be sure to mark the hole with a tall stick so you can find it later. Other options included placing your container in a box and surrounding it with leaves and placing it in a garage or basement. The basic idea is to give it a dark and cold (not freezing) conditions. You can also use a cold frame.

After the correct amount of time has passed, bring your container out and clean it off. If the shoots that have emerged are white don't worry. They will green up with light. Pick a cool spot to start the forcing process. Keep them out of direct sun light for a few days and turn the container one quarter turn each day so the plants grow straight in the container. Keep the pots watered, but not soaking wet. Once blooming has started your flowers will last longer if you keep them out of direct sunlight, and put them someplace cool, (as low as 33 degrees) at night.

If you want to plant the bulbs after they finish blooming cut the flower stems back. Allow the plants to mature. After they wither store the bulbs, pots and all, in a cool dry place until the fall. Then plant them. Remember forcing bulbs stresses them and it may take a couple of years for them to recover and bloom again. Don't be afraid to experiment, and enjoy your early spring flowers!

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