Tip
- Spring Bulbs Brighten Winter Days
The reason people force bulbs is to make them grow and bloom earlier than they would have naturally. But forcing bulbs sounds like a bit of an oxymoron, doesn't it? At my house, bulbs get coaxed into bloom rather than forced. When I'm luring silky petals from hard, brown bulbs, I take time to set the stage. That starts with a comfortable setting, refreshments, and cool temperatures. Then I lower the lights. When show time arrives, the lights and the temperature come up and the urge to emerge is irresistible. No resentful flowers for me!
Many people don't realize that there are really only two types of bulbsfor indoor growing: those you need to pre-chill and those you don't. Here's how to tell the difference. Bulbs that do not need pre-chilling. In this category are amaryllis,freesia, and the tropical narcissus varieties such as paperwhites and 'Soleil d'or.' These zone 8 to 9 bulbs have never known winter, so don't expect a cooling period.
You can plant these bulbs in a pot filled with soil, or just grow themin a shallow bowl and use pebbles to hold the bulbs in place. They'll usually bloom just four weeks after "planting". To help keep stems short and sturdy, provide indirect light and 50 degree F temperatures for the first two weeks, then warmer, brighter conditions after that. If you're growing your bulbs in water, it should cover no more than the bottom 1/4 to 1/3 of the bulb.
Amaryllis are available most everywhere these days, and if you lookaround, you'll find many interesting colors and forms. No need to settle for basic red, when you can have white, candy stripe, or peach, with single or double blossoms.
Some people object to the scent of paperwhites, but I love them. Even more wonderful (and not as off-putting) is the scent of the yellow or yellow/white varieties of tropical narcissus such as 'Bethlehem', 'Soleil d'or', 'Omri' and 'Chinese Sacred Lily'. Buy a couple dozen of these no-chill bulbs and store them in a cool, dry place. Start some every few weeks for blooms right through January.
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Bulbs that need pre-chilling. All other spring bulbs require a chilling period before they'll bloom. This includes tulips, daffodils, hyacinths, crocus, Dutch iris and scilla. Cool temperatures stimulate a biochemical response inside the bulb that "turns on" the embryonic flower so it starts developing. Most bulbs require 16 to 18 weeks of cold before the flower is fully formed. At that point they're ready for light and warmth. If you cut the time short, the flowers will emerge but they will not be fully formed. For indoor blooms, the easiest bulbs are crocus, hyacinth, muscari, and mini-daffodils. Tulips and standard daffodils are a little trickier.
Bulbs seem to look best in a shallow, wide pot. There should be about 2" below the bulbs for root growth. The very top of the bulbs can be even with the pot rim. Use a standard potting mix (2/3 soilless mix, 1/3 compost/soil). Potted bulbs also look best when they're crowded, so snuggle the bulbs together about 1-inch apart. It's also good to stick with one variety of bulb per pot, since cooling and bloom times vary. Label each of your pots with variety name and planting date. You won't remember what's what when February comes.
Finding the right place to chill your bulbs is the real challenge. The bulbs need to be kept at 35 to 45 degrees F for the entire cooling period of 16 to 18 weeks. If you live where outdoor winter temperatures rarely get below 25 degrees F, just keep the pots of bulbs moist and store them right in the garden beneath a layer of straw. If your winter temperatures are colder than that (it gets to minus 25 degrees at my house), the potted bulbs can be stored in an unheated basement, a ventilated crawlspace, or a cold frame.
Here's another option. A friend of mine digs a trench that is two feet wide, six feet long and two feet deep in his vegetable garden each fall. He nestles about a dozen pots in the bottom of the trench, lays row cover fabric overtop, then piles on a layer of straw about two feet deep. Besure to choose a well-drained location and use a soil thermometer to periodically check the soil temperature in the pots. It should be about 40 degrees F. This friend has used a bulb trench for about 5 years now and has successfully coaxed winter blooms from tulips, daffodils, Dutch iris, crocus, and even Lily of the Valley. I'll be giving the idea a try in my own garden this fall.
Check the sidebar for specifics about how long to chill your bulbs. Generally, for flowers in January, you should plant in September or early October. For February flowers, plant mid-October. For March blooms, plant in late October or early November. Keep the soil moist, but not wet for the entire duration. And keep the bulbs in the dark or they may start growing before they're fully chilled.
Time for Spring! Once you remove your bulbs from cold storage, allow three or four weeks to bloom time. Wake the bulbs gradually, starting with about two weeks of indirect sunlight and 60 degree temperatures. When shoots are three to five inches high, move the pots to a 68-degree environment and a bright, sunny window. Once buds color, move the pot to indirect light again to prolong bloom.
After blooming, most people discard potted bulbs. If you find that impossible, keep watering the pots and start adding some fertilizer. When the foliage yellows (usually after a month or two), you can remove the bulbs and plant them outdoors. Just remember they make take several years to build up their blooming energy. Paperwhites and other tropical narcissus will not rebloom.
