Forcing Bulbs

Forcing Bulbs©

By Arlene Wright-Correll

Forcing bulbs not only can give you early flowers, indoors, at the end of a long winter, but can be an enjoyable and rewarding hobby.

Little (minor) bulbs, such as snowdrops, scilla, Muscari, chionodoxa, and crocus force equally well as the large (major) bulbs, daffodils, tulips, hyacinth, and amaryllis. One can force bulbs in dirt or water.

The term forcing refers to inducing a plant to produce its shoot, leaf, and flower ahead of its natural schedule and out of its natural environment. To force hardy bulbs you need to mimic and compress the process the plant would undergo outdoors in the garden. The type of pot (plastic versus clay) is a personal preference. Plastic pots do not dry out as rapidly as clay, are easier to clean and lighter in weight, as well as less expensive. Clay pots have aesthetic qualities in and of themselves and don’t necessarily need a basket or covering to be attractive. Bulbs will grow equally well in either. The pots should be scrubbed clean before use and clay pots soaked for several hours to saturate pores.

When one is buying bulbs for forcing, always choose first-rate, top-size varieties. Mail-order your bulbs by August or earlier to ensure adequate time to receive the bulbs by the first part of October. If you buy from the local garden center, scrutinize them the way you would produce at the grocery store; don’t buy bulbs that are soft or sprouting. High-quality bulbs are necessary because the bulb contains the food required to produce a flowering plant.

Since bulbs need moisture and perfect drainage, a mixture of equal parts peat moss, potting soil, sand and vermiculite or perlite is best. Mix thoroughly and moisten with enough water to a damp consistency. If you anticipate planting bulbs outdoors after forcing, add 1 teaspoon of 5–10–5 dry fertilizer to every quart of soil mix to give the bulbs an extra boost after flowering. Hyacinths, crocus, and narcissi can be grown in pebbles and water—with no additional nutrients, however, they are usually completely exhausted and should be disposed of after blooming.

The following are general rules for forcing:

Begin 15-16 weeks before you expect your bulbs to bloom. To use forced bulbs as Christmas gifts, start in September.

Choose a pot that is at least twice as tall as the bulbs.

Mix a good bulb fertilizer into your potting soil.

Fill the pot with a light potting soil so that when the bulb is placed on top of the soil, the growing tip reaches the top of the pot.

Place the bulbs on top of the soil. They should be placed close together, but should not touch each other or the pot.

Sprinkle soil around the bulbs until only the shoulders are showing.

Water the soil and keep it moist.

Place the pot in a cool dark place, such as a refrigerator. Most bulbs need about 12 weeks of cold storage.
Note: No cooling is required for some bulbs such as Amaryllis.

When the stems are about 2 inches tall, move the pot to a warm sunny spot to stimulate bloom.

Small pots of ivy can be transplanted around the bulbs when they begin to bloom.

Here is the how-to for each bulb, then when it says continue as above, just follow the above directions.

Narcissus or Paper Whites: Use a flowerpot at least 2 inches deep and large enough to hold three to twelve bulbs. Fill the container half full of pebbles. Set the bulbs on the pebbles. Pour in more pebbles until a third of each bulb is covered. Add water until it touches the bulb and place in a cool, dark place. Continue as above.

Amaryllis: Plant one bulb per pot in a good commercial potting soil allowing about an inch of

space between the bulb and the pot. Leave about 1/3 of the bulb exposed. This bulb needs a well-lighted warm place in the beginning, then can be moved to a cooler, shaded interior to make the blooms last longer.

The amaryllis is a tender bulb that will bloom without special treatment when first purchased. It should be potted up in light, rich soil in a pot that is only 1–2 inches larger in diameter than

the bulb. The upper half of the bulb should be exposed above the soil. After watering thoroughly, allow the soil to become quite dry. Water more frequently after the flower stalk appears, but never water when the soil is already moist. Put the plant in a warm, sunny spot until the flower buds show color, and then move it out of direct sunlight.

After blooming, cut off the flowers to prevent seed formation. The foliage should be handled as if it were a sun loving houseplant. Place it in the brightest possible location indoors until it is warm enough to sink the pot in soil outdoors where it will receive dappled sunlight at first. Gradually move it to a brighter location where eventually it has full sun for at least five or six hours daily. Fertilize with a balanced houseplant food at regular intervals to build up the nutrients needed for blooming the following year.

Amaryllis should be brought indoors before the first frost in the fall. Traditionally, the bulb is then given a resting period by placing it in a dark location, withholding all water and allowing the leaves to dry. The bulb may be forced into bloom again after resting eight weeks, or even less, should new growth appear spontaneously. If necessary, repot in a slightly larger container. If the pot is still large enough, remove the upper 2 inches of soil and top dress with fresh potting soil. This completes the cycle, which may be repeated annually for many years of lovely blossoms.

Amaryllis also can be kept growing actively year-round without the traditional rest and subsequent forcing. When handled this way, however, the bulbs probably will not bloom until spring. They still require annual repotting or topdressing along with adequate light and fertilizer to ensure repeated bloom.

Often small plantlets will develop beside a well-grown amaryllis. These may be separated gently from the large bulb and repotted, or they may be left attached and allowed to grow to full size along with the original bulb. You could end up with a large pot containing several amaryllis, all blooming at once . . . a spectacular sight!

With a little care and effort, you can have a steady supply of bulb flowers from late January to April. Forcing bulbs into flowering can be a great pleasure and challenge for anyone who is interested in flowering plants.

Hyacinths: These bulbs can be forced in 8-10 weeks. Plant in a good commercial potting soil so that the tips are near the surface or protruding slightly. Keep them in a cool dark place until the shoots are 4-5 inches tall. After this period, provide abundant light.

In this picture you see an odd shaped vase. This is a glass vessel with an interesting shaped neck, sort of like a modified hourglass with an open top. The antiques dealers say it is called a hyacinth glass. This was a special glass that used to be used to force hyacinths to grow without using soil.

An old-fashioned precursor of hydroponics! One can also use small jars if the openings are also tiny. The point of a forcing glass is that it will hold the bottom of the bulb away from the water. A bulb sitting directly in water tends to rot - but if the basal plate on the bulb sits just barely out of the water's reach, it will start to send down roots, and eventually send up a bloom. It's probably a good idea to get your bulbs first if you can't find a traditional forcing glass, and then check to se what you have that might work. Try horseradish jars, baby food jars - or you can now buy the traditional forcing glasses at many nurseries and mail order companies.

If you are going to be traditional and use hyacinths, here's what you do. Fill the jar so it barely tickles the bottom of the bulb, but doesn't really touch it. Make sure the tip is pointing up, because this is where the flower will emerge.

Then stick the vase, bulb and all, into the refrigerator or some other cool, dark place where the temperatures won't rise above 50 degrees- perhaps an unheated garage or porch if you haven't spare refrigerator space.

How long will it have to stay there? That depends on your hyacinth bulbs. Sometimes they are available pre-chilled, which will cut several weeks off of its dark and lonely exile - you may see top growth in as little as 6-8 weeks. But if you buy your bulbs off the shelf or out of a bin at the local nursery, then it can take as long as 13 weeks. So, be patient.

Check on your bulb every so often and replenish the water so that it stays just millimeters away from the bottom of the bulb. You'll see roots begin to emerge and fill the glass. Finally, you will see a little whitish-colored shoot emerge from the top.

Only at this time can you bring your hyacinth out into the light. Don't drench it in brightest sunlight - filtered light in a room with temperatures of between 60 and 70 degrees is perfect. Keep it there until the shoot turns green

Once the hyacinth flowers this way, it can last two to three weeks. You are likely to encounter only one difficulty, and that is that the bloom can get so heavy that it tries to topple out of the vase. With no soil to anchor it, this can be a bit of a problem.

Bulbs forced in water, however, should be considered disposable. Without any soil or direct outdoor sunlight to nourish the bulb, it will be totally exhausted when it is done flowering. Take a bamboo pick or other skewer and stick it right into the bulb and tie the flower upright. Go ahead and stick it right through the side of the bulb and into the glass. It will only hurt you for a moment - and is far better than seeing that bright, promising flower come toppling onto the tabletop.

You can do exactly the same with paper white narcissus - except that it's much easier and faster. These bulbs don't require pre-chilling. All you need to do is set them on top of the glass and add water to the required level and wait. Using forcing glasses is an old idea that has become new again - and can look totally charming when you set a cluster of them on your table as a reminder that spring is coming.

These varieties force well: Amethyst, Blue Jacket, Jan Bros, L’Innocence, Pink Pearl, Delft Blue, Hollyhock, Anna Marie, Violet Pearl, Gypsy Queen, Carnegie

Tulips: What can be lovelier than a dish or pot of colorful tulips on your dining room table or anywhere in your home for that matter?

Pre-cooled early tulips can be forced into bloom by Christmas. Keep them cool for three weeks before moving to a warm, sunny place. These varieties force well. Apricot Beauty, Bing Crosby, Edith Eddy, Mirjorma, Yokohama, Jingle Bells, Attila, White Dream, Princess

Victoria, White Swallow, Estella Rijnveld.

Crocus: The early harbingers of spring can be yours even earlier with forcing. These varieties of Crocus force well. Pickwick, Rembrance, Flower Record, Peter Pan, Purpurea Grandiflora

Crocuses bloom 10 to 18 weeks after planting. When buying bulbs from a mail-order source or garden center, look for varieties identified specifically for forcing.

1. Choose bulbs that are large, firm, and free of nicks

and holes. Keep in mind that the larger the bulb, the larger the bloom.

2. Once you have your crocuses home, pot them up immediately so that the corms do not dry out. Keep in mind that the larger the bulb, the larger the bloom.

3. Select a small container and fill it almost to the top with potting soil. Press in crocus bulbs.

4. Place the crocus corms in the soil mixture close together with their tips just peeking out of the soil. Water the bulbs, and then place the container in a cool, dark spot for 8 to 15 weeks. When the corms begin to sprout, move them to a warmer spot in direct sunlight.

Daffodils and Narcissi: Nothing looks prettier or more spring-like at the end of winter than a bowl of daffodils and narcissi. These varieties force well: Barrett Browning, Bridal Crown, Dutch Master, Ice Follies, Paper whites, Golden Harvest, Spell Binder, Salome, Pink Charm, Flower Record, Louis Armstrong, Unsurpassable, Tete-a-Tete, Jenny, Barrett Browning, Cheerfulness

Here are 3 simple steps to follow:

Fill your pot half full with potting soil. Use a soil mix that retains moisture, but allows good drainage.

Place as many bulbs as you can, but don't let the bulbs touch. Their growing tips should be even with the top of the pot.

Water the bulbs thoroughly and label each pot with the planting date. Then, move them to cold storage.

After roots thrive

Once you see roots poking out of the bottom of the pot, or growth at the top of the bulb, move the pot to a sunny spot.

Don't move the potted bulbs into the light too soon. They need adequate cooling time before warming up; if cooled too briefly, the bulbs may sprout, but you will be disappointed with the bloom.

Muscari: Planted in shallow dishes, low-growing Muscari—also called grape hyacinth—make stunning and unusual centerpieces. Muscari (Grape Hyacinths) is available in both purple and white and emit a wonderful fragrance. They thrive and multiply easily and make great borders and accents. In addition to the traditional form of bloom that resembles a cluster of grapes, Muscari also is available in a variety called plumosum, a.k.a. Feather Hyacinths. Occasionally overlooked in outdoor gardens, the diminutive, electric-blue Muscari commands the spotlight when placed at center stage on a dining or coffee table. These

force well: Blue Spike, Early Giant and the best species of Muscari to force is the blue armeniacum, which grows 8 to 10 inches tall.

Others that force well are Snowdrops, Dutch Irises, Blue Squill, and Glory-of-the-snow

When one forces in water, one must discard the bulbs, but when one forces in dirt, after flowering, cut the flower stems and place the pots in direct sunlight, keeping the foliage growing until it begins to die back. As it withers, don’t pull the leaves off, store the bulbs in the pots in a cool, dry place until late summer or early fall, at which time they can be planted into the garden. Attempts to force the same bulbs indoors will be unsuccessful; as forcing weakens the bulb and the bloom will be small and unsatisfactory the following year. Once the bulbs are back in the garden setting, they will return to a natural schedule, and in several years will again produce a wonderful show of flowers.

To recap, just remember the following: Amaryllis needs no chilling, start in a warm dark place and move to light when the stalk is 4".

Hyacinths may only need 10 weeks of chilling and begin to flower in as little as a week or so after moving to warmth.

Tulips and daffodils will take four to five weeks to be in full bloom after chilling.

Crocuses and grape hyacinths make a great show when planted in masses.

Freeesias and Calla lilies may also be forced without chilling.

Paperwhite narcissus takes no chilling.. they'll sprout just about anytime, anywhere.

The autumn crocus (Colchicum autumnale) takes no chilling.

Lily of the Valley (Convallaria majus) will bloom in 3-4 weeks if potted up at 65 degrees

Dutch iris (Iris reticulata) takes no chilling, should be fed every 2 weeks

Bluebells (Scilla) take no chilling, and little effort

“Tread the Earth Lightly” and in the meantime… may your day be filled with….Peace, light and love,

Arlene Wright-Correll

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