Van Bourgondien

Forced Bulbs FAQ

Q: I bought some spring-blooming bulbs in September, but never got around to planting them. Now it's December and the ground is frozen. I have daffodil, tulip, crocus, snowdrop and grape hyacinth bulbs. What can I do?

A: First, check the bulbs and discard any that are bruised, soft or rotting. You can pot up the healthy ones, keep them cool for 12-15 weeks and force them into bloom inside. If you start now you can enjoy colorful, fragrant spring flowers on your windowsill by late March. You can have flowers even earlier if you pot up tropical bulbs such as amaryllis or paper white narcissus that don't need pre-chilling.

Q: Right now I'm concerned about those spring-blooming bulbs that I didn't get around to planting outdoors. To force them to bloom indoors, what kind of pots should I use?

A: You can use decorative or functional round, oval, square or oblong containers that are deep enough to accommodate the bulbs and about two inches of soil. They can be made of plastic, ceramic, terra-cotta, resin, wood or metal, though if using the latter two, you might want to line the inside with plastic to protect the wood from rotting and the metal from rusting. For a touch of whimsy, use a found object such as an old boot or shoe, a birdhouse with no top, etc. that is deep and sturdy enough to hold soil and a few bulbs -- just don't forget to protect your “pot” with a plastic liner, if necessary. The most important things to remember are a) your container, traditional or unique, must be clean and b) it must have drainage holes. If your containers don't already have drainage holes, you must drill them. Here's an important tip: if using terra-cotta pots, soak them overnight before using them so the clay won't wick moisture out of the soil.

Q: What kind of soil is best?

A: Use a commercial potting soil mix. These mixes come in several sizes and can be found at garden centers, hardware/home improvement stores, “big box” stores, and even in grocery stores. Almost any soil mix will do, but those with added fertilizer are an unnecessary expense. Bulbs come already “packaged” with everything they need to grow and bloom right inside.

Q: How do I know which end of the bulb is up?

A: It can be tricky with the smaller bulbs. Look for tiny, rootlike protrusions; the side from which they grow is the bottom of the bulb. But don't be too concerned; though right side up is best, they should grow upright even if the bulbs are mistakenly planted sideways or upside down. Tulips and daffodils are easy; they are pointed on top.

Q: How do I plant my bulbs?

A: Fill each pot loosely with soil mixture so that larger bulbs like daffodils and tulips will have at least 2 inches of soil beneath them. Tulips and daffodils should be left with the tips of the bulbs showing just above the soil, but smaller bulbs such as crocus, snowdrop and grape hyacinth should be covered completely. Be gentle. Don't press the bulbs into the soil too firmly; this will allow the roots to grow through it more easily. After setting the bulbs, fill your pot with soil to within ¼ inches of the pot's rim. As you can see, it is best to use shallower pots for smaller bulbs. Next, add water until it drips through the drainage holes in the bottom of your pot. Then, label each pot with the name of the bulb (including its cultivar name, color, height, etc.), the date you planted it, and the date it will be ready to force (12-15 weeks from the day you pot up your bulbs). Don't forget to mark that latter date on your calendar.

Q: How many bulbs go in each pot?

A: A good rule of thumb is to plant a 6 inch wide pot with either 3 hyacinth, 6 tulip, 6 daffodil or 15 crocus bulbs. As you go, you will soon get the hang of how many of each bulb to plant in different sized pots.

Q: What's next?

A: Now look for a place to store the planted pots. You need a dark place with temperatures that range between 35 and 50 degrees F. Depending on where you live, look for a cool basement, unheated garage (as long as the temps don't go too low), a heavily mulched (so the bulbs don't freeze) outdoor trench or cold frame (protect the bulbs from squirrels and other critters with hardware cloth) or other space that can be kept within the right temperature range. If you have an old working refrigerator, that is ideal. Just make sure that the bulbs are not placed next to fruits (such as apples) that emit ethylene gas, which will harm the bulbs. Be extra careful to keep small children from mistaking them for food, as some bulbs are poisonous. Remember to cover the pots carefully to keep out light. It's wise to check them in about six weeks or so to make sure they aren't drying out. If so, add only enough water to make them moist, not wet.

Q: How long do the bulbs need to be chilled?

A: Expect a minimum cooling period of 12 and a maximum of 15 weeks. Though spring-blooming bulbs planted outside in the fall in the northern U.S. will stay in the ground for at least six months before blooming, bulbs will bloom after a much shorter chilling period in southern states. No matter where you live (except in frost-free areas like southern Florida), as the sun warms the earth in the spring, the bulbs will sprout and grow and bloom right on schedule (Mother Nature's schedule). It is that process that you a re-re-creating when you force bulbs to bloom indoors.

Q: How do you know whether they are ready to be forced?

A: Remember, you labeled your pots with the date you put them into cold storage and marked on your calendar the approximate date they'd be ready to come out. Once you have chilled the bulbs for at least the minimum time needed, you can check them to make sure they have formed roots. Bulbs can't be forced unless they have formed healthy roots in a planting medium; this is why it won't work if you try to force them in the packaging they came in.

Gently tip out the soil in one pot. You should see healthy white roots. If you don't see roots, replace the bulb in the soil, place the pot back in storage and check again in a week or so. Sometimes the bulbs begin sprouting while in cold storage; that's normal and means they're ready to be forced.

Q: Okay, I see roots. What now?

A: Bring your pots out of storage into a room where they will receive indirect light and temperatures of 60-65 degrees F. This will stimulate the bulbs to begin active growth. When the shoots begin to turn green, move the pots into brighter light and warmer temperatures to promote flowering. Rotate the pots ¼ turn every day so all the leaves will receive an equal amount of sunlight. Begin looking for flower buds in about 3-4 weeks.

Q: Is there something I can do to make the flowers last longer and the plant continue to send up new flowers?

A: Yes. To help make the flowers last longer, move the pots into bright, but indirect sunlight during the day and provide cooler temperatures at night. Remove spent blossoms as they fade to keep the plants from producing seed. If they can't produce seed, they will keep flowering. Eventually, though, the plant will run out of energy and flowering will stop.

Q: Do I have to throw away the spent bulbs, or can I plant them outside in the spring?

A: That depends on the bulb. Some, such as daffodils, can be planted outside in the spring, but be prepared to wait a long time for more flowers. It can often take two or more years before the bulbs have regained enough strength to bloom again. Some bulbs, tulips for instance, will never bloom again, and should be discarded after they stop flowering.

Q: Can you recommend some daffodils for forcing?

A: Two excellent ones are Tête-à-Tête, a very fragrant 6-8 inches tall charmer with 2-3 small, yellow, long-cupped flowers on each stem; and 'Golden Bells', also known as 'Yellow Hoop Petticoat', a 7-8 inches tall darling with an unusual bell-like shape and multiple stems per bulb. You could also try the taller ruffled cup daffodils. At 16-18 inches tall they include 'Ice King', white with a ruffled yellow cup and 'Rose Cloud', white with a pink ruffle cup. The two make a beautiful combination. 'Fidelity', at 18 inches tall is light yellow with a large pink trumpet. There are many other daffodils that are also suited to forcing. If you are looking for the unusual, try 'Palmares', a gorgeous butterfly daffodil in creamy white and salmon.

Q: Which tulips are best for forcing?

A: The easiest tulips to force are Triumph, Single Early, Double Early and Darwin Hybrids. There are several of each to choose from. You can put a single color in each pot, or combine colors as you wish. Particularly nice combination of Triumphs include the dark purple 'Negrita' with soft pink 'Esther'. Another is a mixture of pink, white and pink and white bi-colors that is reminiscent of apple blossoms.

Q: What other bulbs can be forced?

A: Crocus, Dutch iris, hyacinth, grape hyacinth, and many other bulbs can be forced, but not all are as easy as daffodils and tulips. If you really like a particular flowering bulb, try it. Experiment to see what works for you.

Q: I want to have flowers blooming in time for my niece's wedding shower in early February. What bulbs can I force that will bloom by then?

A: Congratulations to the prospective bride and groom. Your best bet would be paper white narcissus, Narcissus tazetta 'Paper White'. These fragrant white daffodils are tropical bulbs that need no pre-chilling and are easy to plant and care for. They should give you gorgeous, highly scented white flowers in about four to eight weeks on strong, 16-18 inches tall stems. Paper whites can be planted in one of two ways: in a pot filled with soil (leave the tops of the bulbs exposed), or in a shallow (at least 2 inches deep), decorative bowl with no drainage holes. Use a layer of pebbles, pea gravel or sand in the bowl to hold the bulbs in place. Don't worry about crowding them; it's all right if they touch each other. If you used soil, add water until it drips through the drainage holes on the bottom. If you are using a bowl, add just enough water to cover no more than the bottom 1/4 to 1/3 of the bulbs. (Use a clear glass bowl if you are interested in watching the roots grow.) After planting, provide indirect light and temperatures of about 50 degrees F for the first two weeks or so, until the shoots appear. After that, move them into a warmer, brighter room and watch them grow and bloom. Since the bulbs must be discarded after flowering (they can't be forced again), buy several dozen at once and store them in mesh bags in the refrigerator (away from fruit). You can keep the flowers coming if you plant another bowl or two every other week.