CO-Horts Blog

Monday, October 20, 2014

Forced fall bulbs provide winter color

Kathy Steffa
Colorado Master Gardener -- Chaffee County

My favorite fall bulb catalogs have arrived, and I am preparing my order of bulbs to grow indoors this winter. Two benefits of this are that I can grow tender varieties that wouldn't survive outside, and I don't have to worry about bad weather and sudden snowstorms.

The easiest bulbs to force are Paperwhite Narcissus which are usually grown in pebbles with water no higher than the bottom of the bulbs. Since I worry about overwatering and rotting the roots, I prefer to grow them in plastic pots with a mixture of half garden soil and half peat-based potting soil. The bulbs often arrive already growing, so I put them in bright light for three days until the shoots green up, then I move them to full but cool sun. Cool temperatures and regular rotation of the pots results in strong, straight stems.

All paperwhites are very strongly scented. The Chinese Sacred Lily has an orange cup; Grand Soleil d'Or is yellow and orange and should be grown in potting soil only as it takes longer to come into bloom.
The other bulb commonly forced in water is the Hyacinth, for which attractive eggcup-shaped glass vases are available. Carefully remove all the outer dry husk and add water to just below the bottom of the bulb. Do not put any fertilizer in the water.

Blooming is apt to be more successful if you purchase specially cooled bulbs. Otherwise, keep the vase in the dark at a very cool 50 degrees F. until the flower stalk is completely out of the bulb. Check the water level weekly and top off as it evaporates.

Amaryllis are another very easily forced bulb, and there are new varieties including Cybister hybrids and the Papilio "butterfly" which is green and maroon flowered. Both of these are evergreen houseplants and are never forced into dormancy by cutting off the leaves. Miniature hybrids, often not much shorter, and Trumpets have also been developed.

Christmas-flowering Amaryllis come into bloom earlier than the Dutch ones because they come from South Africa. They are supposed to have more leaves on the plant when it blooms so that the flower doesn't look so naked. Never remove dry, dead-looking roots from an amaryllis bulb as they do absorb nutrients until new roots form.

Almost as easy to grow as Paperwhites and Amaryllis are unfamiliar bulbs which do not require twelve to sixteen weeks of pre-chilling. I start these on the garage floor, covered with black plastic until I see some green growth. This has included Anemone blanda and A. coronaria, Dichelostemma, Dracunculus, Freesia, Ipheion uniflorum, Ixia, Ixiolerion, Lachenalia, Ornithogalum dubium (can't tell beforehand if they will be yellow or orange!), Pancratium maritimum, Ranunculus, Scilla peruviana, Sparaxis and Veltheimia bracteata. Calochortus and Fritillaria davisii and F. pudica have not been successful for me.

Once a green leaf shows, move the pots to a place in cool sun where the temperature ranges from 40 degrees F. at night up to about 60 degrees F. daytimes. (If the nights get cold enough to start freezing the soil in the pots, bring them in to a warmer place even if they aren't yet showing any growth.) They will grow slowly and bloom in two to four months. I fertilize them lightly with a diluted low-nitrogen and kelp powder mix at every watering and watch for aphids as the winter days lengthen and warm up.

When flowering is completed, Paperwhites are usually discarded. Hyacinths can be planted in a pot after bloomiing and saved until spring but will need two or three years of growth in the flowerbed to rebloom.

Keep watering the bulbs with the dilute fertilizer solution until the leaves dry up and save the bulbs in a cool place to replant next fall. Those hardy in Zones three and four can be planted outdoors for bloom next spring.

The ultimate indoor bulbs are garlic and Egyptian or walking onions. Let them grow eight to ten inches tall, then pull them up and chop into soup, salads and other foods for a touch of green at the winter table. Enjoy!

Websites of bulb companies include:,, and Alternatively, you can shop locally and mix-and-match the exact bulbs you want on a planting day convenient to you.

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