An Appropriate Time to Resort to the Use of ‘Force’

Brighten Winter Days by Forcing Bulbs Indoors

If you’re the type of gardener who spends the winter months anticipating the first flowers of spring, you might want to try “forcing” bulbs. By providing favorable conditions indoors, you can trick many bulbs into blooming during winter—well before they would normally flower outdoors. This technique is called forcing, which stimulates a plant to bloom out of season.

Though the effects are stunning, forcing bulbs is quite easy. By controlling the climate, you create an environment that causes the bulb to bloom earlier.

Now is the perfect time to make your selections for forcing, said Marty Bailen, a nursery salesman at Rogers Gardens in Corona del Mar.

“We have a great selection of bulbs now,” he said. “For forcing, you want the biggest bulbs possible because they’ve stored the most energy and will give you the best show.”

Why Force Bulbs?

  • Brighten up the house when the garden is dormant
  • Many forced bulbs are fragrant
  • Containers make inexpensive and impressive holiday gifts
  • Fun indoor activity for children

Best Bulbs for Forcing

According to Bailen and Dan Davids of Davids & Royston Bulb Co. in Gardena, these are the best choices:

  • Paper-white narcissus
  • Hyacinth
  • Amaryllis (especially South African varieties)
  • Chinese sacred lily (Narcissus tazetta)
  • Soleil d’Or (Narcissus tazetta)
  • Iris danfordiae
  • Iris reticulata
  • Crocus
  • Tulips

Note: Forced bulbs often use up their food supply and may not bloom again. Most are best discarded after flowering.

Methods for Forcing Bulbs

1. Water Forcing

  • Use conical or hourglass-shaped containers
  • Place bulb above water line; roots grow down into water
  • Bulbs must not touch the water to avoid rot

2. Medium Forcing

  • Use pebbles, sand, vermiculite, or perlite to support bulbs
  • No nutrients in medium, but it keeps bulbs upright

3. Soil Forcing

  • All bulb types can be forced in potting soil
  • Amaryllis must be forced in soil rather than water

How Long Do Forced Bulbs Bloom?

  • Amaryllis: 2 to 3 weeks
  • Paper-whites: About 1 month
  • Hyacinths: 2 to 4 weeks
  • Tulips: Just 1 week

Tips for Successful Bulb Forcing

  • Choose large, firm bulbs—avoid soft or damaged ones
  • Pre-chill certain bulbs (hyacinth, crocus, tulips) for 4–6 weeks in a ventilated bag in the vegetable crisper
  • Use suitable containers for each method
  • Place water-forced bulbs just above the water surface
  • Embed bulbs halfway to three-fourths into the medium for soil or pebble forcing
  • Add activated charcoal to water to prevent odor or change water frequently
  • Pack bulbs closely for a fuller color display

Rooting and Lighting Guidelines

After planting:

  • Place in a cool, dark place (e.g., basement or garage) for root development
  • Hyacinths may need up to 6–7 weeks in darkness
  • Move to dim light once roots and growth appear (4–6 inches tall)
  • Gradually increase light exposure until ready for a bright room

Alternative method: Dan Davids suggests skipping the dark period. Start bulbs outdoors in the shade and move them indoors after 6–8 inches of growth.

Care Tips After Forcing

  • Place in a bright but indirect light location
  • Avoid drafts, heater vents, and direct sunlight
  • Water when medium dries or water level drops
  • Discard bulbs once blooms fade—they won’t rebloom

Estimated Bloom Times from Planting

  • Amaryllis (South African): 8–12 weeks
  • Chinese sacred lily: 6–12 weeks
  • Crocus: 6–12 weeks
  • Hyacinth: 12–16 weeks
  • Iris danfordiae / reticulata: 12–16 weeks
  • Paper-whites: 4–6 weeks
  • Soleil d’Or: 6–12 weeks
  • Tulips: 12 weeks

Julie Bawden-Davis

Julie Bawden-Davis is a bestselling journalist, novelist, blogger, and YouTuber. A prolific author, Julie writes in several genres. She enjoys creating page-turning suspense served up with a dose of romance, garden books that turn any brown thumb green, and spiritual books meant to enlighten and inspire. Widely published, Julie has written 45 books and more than 4,000 articles for a wide variety of national and international publications. She lives in Southern California, where she enjoys sunny, blue skies most days and year-round gardening. Julie gains inspiration from being surrounded by plants when she writes.