Indoor Bulbs
By on Apr 23, 2008
By Veronica Sliva
Nothing is quite as uplifting as the appearance of cheerful spring flowers after months of dreary winter weather. But with a little forethought, you can have containers of daffodils and other spring bulbs blooming indoors as early as January.
"Forcing bulbs" is the technique of tricking these plants into blooming early. There are two types of bulbs for indoor growing: those you need to pre-chill and those you don't. Let's take a look...
Bulbs that need pre-chilling
For bulbs that require a chilling period, just mimic Mother Nature. Forced bulbs, like those that bloom in the garden, require cool temperatures to stimulate a biochemical response. To force bulbs into bloom, give them the minimum amount of chilling they need to develop and then create a false spring by bringing them into a warm, bright room.
Bulb selection
The easiest bulbs for forcing are crocuses, hyacinths, muscari, and mini-daffodils. Tulips and the larger daffodil varieties can be forced too, but once they start growing they require lots of sunlight and can be more of a challenge to force successfully.
Planting method
Choose a container?plastic or clay pots will do as long as they are clean and have a drainage hole.
Cover the bottom of the pot with about 2.5 centimetres (1 inch) of gravel to provide good drainage. Then add 5 to 7 centimetres (2 to 3 inches) of good quality potting soil. Do not add fertilizer because the bulb already has all the nutrients it needs for flowering.
Snuggle the bulbs into the soil as close together as possible but without touching one another. The pointed ends must face upwards.
Fill the pot with soil until only the tips of the bulbs are peeking out. Label the pot, water well, and place into a plastic bag to retain moisture.
Storage
The potted bulbs must be kept in cold storage until a good root system develops. An unheated garage, cold cellar, cool attic, or even a refrigerator work well. A temperature of 7 to 10°C (44 to 50°F) is ideal, but never below freezing. Every now and then, check to see if the pots need watering. The soil should be kept moist, but not soaking wet.
Forcing
The length of necessary cold storage time varies with bulb types. Most require a cold period of 12 to 16 weeks to establish a good root system. At around 12 weeks, check for root growth. When roots fill the pot and poke out through the drainage holes, it's time to wake the bulbs gradually. Start by putting them in a spot with indirect sunlight for a couple of weeks. When the shoots are 7.5 to 10 centimetres (3 to 5 inches) high, move the pots to a bright, sunny window. Once the buds show colour, move the pots back to indirect light in order to prolong the blooming.
After blooming, you can discard the bulbs or plant them outdoors, although it may be several years before they bloom again, if at all. Bulbs that do not need pre-chilling
Paperwhites
Among the easiest bulbs to grow indoors are paperwhites. An effective room deodorizer, this cheerful member of the narcissus family is intensely fragrant and one pot easily permeates a large room with its sweet, musky fragrance. As the name suggests they are generally snowy white, but yellow varieties also exist.
Tuck several of these bulbs into a container filled with pebbles. Add water to cover no more than the bottom 1/4 to 1/3 of the bulb. To help keep stems short and sturdy, provide indirect light and temperatures of about 10°C (50°F) for the first two weeks and warmer, brighter conditions after that. You'll have scented blooms in just four weeks. What could be simpler?
Amaryllis
Big, bold, and beautiful, amaryllis blooms make a decorative statement in any home. Plant a single bulb in a pot, adding about 2.5 centimetres (1 inch) of soil around the bulb. Set the bulb so that about 1/3 of it shows above the soil level. Water well and place in a warm, sunny location. Flowering occurs in four to six weeks. As the plant grows you may need to stake it to keep the top-heavy flower stalk upright.
It's possible to get your amaryllis to bloom again. After the flower fades, cut off the stalk, but not the foliage. Keep the plant in bright light and continue to water and fertilize. In spring, when the danger of frost has passed, plunge the pot into the garden. Late in the summer when the leaves turn yellow, decrease watering. After the foliage has died back, let the soil dry out. The bulb is now dormant and should be stored in a cool, frost-free place. In November, bring the pot into bright light and start watering again. With luck your amaryllis will reward you by re-blooming.