OE wyrtig, adj: Garden-like, full of plants;
On anum wyrtige hamme, Homl. Skt. ii. 30:312.




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Forcing Bulbs for Winter Beauty


Getting bulbs (and corms and tubers) to bloom when you want them to is called "forcing," a variety of indoor gardening that allows you to enjoy flowering plants throughout the winter months.

Some of the lovely plants that can be induced to bloom for you in the winter include:

  • Anemone blanda, Windflower

  • Chionodoxa, Glory of the Snow

  • Crocus vernus, Spring crocus

  • Eranthus hyemalis, Winter aconite

  • Freesia hybrids, Freesias

  • Fritillaria meleagris, Guinea flower

  • Galanthus, Snowdrop

  • Hippeastrum, Amaryllis

  • Hyacinthus orientalis, Hyacinth

  • Ipheion, Starflower

  • Iris danfordiae, Dwarf iris

  • Iris reticulata, Netted iris

  • Leucojum aestivum, Snowflake

  • Muscari, Grape hyacinth

  • Narcissus tazetta, Paperwhites

  • Narcissus, Daffodils

  • Ornithogalum, Star of Bethlehem

  • Ranunculus, Buttercup

  • Tulipa, Tulips

Choose the healthiest bulbs you can find to use for this. You can purchase them ahead of time and store them in the refrigerator for two to three weeks before potting them up (this time doesn't count as part of the cold treatment time). Be careful not to store bulbs near apples and other ripening fruits or vegetables.

Time to chill out

Most bulbs (and tubers and corms) require a period of cold after they are potted up in order to flower. This "cold treatment" is simple process, though care is needed so that bulbs are moved to warmer quarters at the right time.

Different bulbs require different periods of cold treatment (see table, below). The only way to know whether your bulbs have chilled long enough is to actually look at the plant itself. Cold treatment should end when you see:

  • Roots just beginning to come out of the bottom of the pot

  • The tip of the new plant just beginning to emerge at the top of the bulb

How long to keep cool


After potting up, chill at 35-45o F for:

Anemone blanda, windflower

8-12 weeks

Chionodoxa, Glory of the Snow

10-14 weeks

Crocus vernus, spring crocus

12-14 weeks


16-17 weeks

Eranthus hyemalis, winter aconite

8-12 weeks

Freesia hybrid

No chilling; grow in bright, cool place; blooms in 4-8 weeks

Fritillaria meleagris, Guinea flower

13-15  weeks, keep moist

Galanthus, Snowdrop

12-14 weeks

Hippeastrum, Amaryllis

None; blooms 6-7 weeks after planting

Hyacinthus orientalis, Hyacinth

11-14 weeks
Ipheion, Starflower 10-12 weeks

Iris danfordiae, Dwarf iris

14-20 weeks

Iris reticulata, Netted iris

10-12 weeks

Leucojum aestivum, Snowflake

10-12 weeks

Muscari, Grape hyacinth

14-15 weeks

Narcissus ssp.

10-12 weeks

Narcissus tazetta, Paperwhites

None; blooms 4-6 weeks after planting

Ornithogalum, Star of Bethlehem

12-14 weeks

Ranunculus, Buttercup

None; grow in bright, cool place; blooms 4-8 weeks after planting


15-18 weeks


More than one kind of bulb can be planted in single pot, but it is important to choose bulbs that require the same length of cold treatment, so that they will all flower simultaneously.

With a little planning, you can have plants in flower all winter. For  example, if you want hyacinths in bloom for the holiday season in December, pot them up and put them in the refrigerator in mid-September.


Potting up

Pots - Start with clean pots. Choose a pot at least twice as deep as the bulbs to allow for root growth. Pots should have holes in the base for drainage (and also so you can see if roots are growing).

Soil - Use fresh potting soil with equal parts soil, sphagnum moss, and sand or perlite. Avoid potting soils that are primarily sphagnum moss; these retain too much moisture and can cause bulbs to rot. Also avoid potting soil mixes that include fertilizer. Potting soil should be moist, but not soggy.


Start by filling the pot with at least 1"-2” of soil, pressed down firmly. Then place as many bulbs as will fit in the pot, but don’t let them touch.

Cover the bulbs of hyacinth, tulip,  and narcissus just enough so that their tips are slightly above the surface of the soil. Other bulbs should be covered by at least an inch of potting soil. It is more important to have ample soil beneath the bulb than above it. Don’t fertilize.

When bulbs and soil are in place, water until you see water coming out of the drain hole at the bottom of the pot. Allow the pot to drain for 15 minutes.

Put a label in the pot with the plant name(s) and the potting date; then put the pot in a paper bag. Close the top of the bag by rolling it over one or two times, but don't tape or staple it shut. On the outside of the bag, write the planting date in a place where it is easy to see, along with the number of weeks of cold treatment for this plant..

Cold treatment

Place the bagged pot in a dark, cool (35-45o F) place, such as a refrigerator, garage (where it won't get below freezing), or very cold basement.

Bring on the blooms - About half way through the cold treatment period (see the table above), begin checking the plant about once a week. When you see roots beginning to poke out of the bottom of the pot, or a sprout emerging from the tip of the bulb, remove the bag. Move the pot to a warmer (50-55o F) location with low to medium light.

When shoots begin to turn green, usually 4 to 5 days, move the pot to a brightly lit, warm (60-65o F) location. Keep soil moist but not sodden.

When flowers appear, move the pot out of direct sun so that the blooms last longer. Remove spent flowers as they wilt.

Saving the bulbs

Bulbs can only be forced one time, but they can be saved and replanted in the garden, where they will often bloom again next season. To save bulbs, move the pot to sunny window after the flowers are done. Water regularly until the foliage withers and dies; then trim the dead foliage away. Take the bulbs carefully out of the pot and gently dust off the dirt. Let the bulbs dry for 2-3 weeks. Then store in a paper bag in a cool, dry place until planting out in the fall garden.

Other resources
Bulbs for Indoors: Year Round Windowsill Splendour, edited by Hays and Marinelli.


Anemone blanda


Crocus vernus



Fritillaria meleagris





Iris danfordiae

Iris reticulata



Narcissus tazetta





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