by OCMGA Master Gardener Tammy Borden
Who says gardening has to wait until spring? By forcing bulbs you are convincing a spring bulb that it has slept through the winter months and are encouraging it to bloom early. It’s wonderful to have bright blooms and sweet scents during the grey and drab days of winter.
Forcing bulbs is not too difficult. It just takes time, patience, and a little advance planning. It may be a little late to start forcing some types of bulbs for this winter, but some bulbs are ready to go and need no advance planning! Here are some easy steps to getting your own beautiful indoor blooms.
Step #1 – Select Your Bulbs
Many bulbs require pre-chilling in order to grow indoors (35-40ºF is recommended – like in your refrigerator!). The catch here is that many ripening vegetables and fruits, especially apples, release ethylene gas, which can kill or damage the flowers, so if you store produce in your refrigerator, try a partially heated garage instead or use bulbs that do not require pre-chilling. Here are some suggestions for bulbs that work well for indoor forcing:
- Amaryllis (requires no chilling)
- Hyacinth (12-16 weeks of chilling)
- Tulip and daffodil (12-16 weeks of chilling)
- Crocus and grape hyacinth (12-14 weeks of chilling)
- Paperwhite narcissus (Requires no chilling)
- Autumn crocus or Colchicum autumnale (Requires no chilling)
- Dutch Iris or Iris reticulata (Requires no chilling, but should be fed every 2 weeks)
- Bluebells or Scilla (Requires no chilling)
Step #2 – Prepare Your Bulbs
There are several methods for growing bulbs indoors. Here are the most common:
Pebbles & Water: Simply take a clear glass bowl, fill it with gravel or decorative stone. Firm the base of the pre-chilled bulbs into the pebbles until they stand firmly on their own. Next, fill water up to the base of the bulbs, but not high enough that it touches them (about 1/8 away). Keep it in a cool, dark location for a few weeks until they’re ready to bloom to help maintain strong stems and encourage root growth.
Water Forcing: There is an hourglass-shaped vase you can buy called a ‘Hyacinth Glass’. Simply fill the container with water, up to the tapered neck, set the pre-chilled bulb on the widened mouth of the container and it’s ready to grow. Again, do not let the bulb touch the water. Place bulbs in a dark, cool place for a few weeks before blooming.
Potting in Soil: Shallow pots are usually used for forcing, but you can use most any container, if it has holes for drainage. Fill the pot about 3/4 full with a peat based potting mix. Squeeze in as many bulbs as you can fit. You can use all one type or mix and match, but choose bulbs with a similar bloom time. Plant the bulbs flat side down and cover with potting mix. Leave the shoot tips poking out slightly above the soil line. Water until it comes out of the drainage holes. Next, chill the pot and all for the recommended time (above). You can do this by burying it in the ground outside, placing it in your garage, or in a refrigerator. When you bring the pot indoors, keep it in cooler temperatures for a few weeks until it’s ready to bloom.
Step #3 – After the Bloom
Unfortunately, forcing takes a lot out of a bulb so it may not bloom again for many seasons. Still, bulbs can be planted outside when the weather permits just as with any perennial. Do not remove the foliage until it has turned yellow. The bulbs should never be forced a second time, always start with new bulbs.
Have some fun this winter and give forcing a try!