Lowenfels: Forcing bulbs lets Alaskans keep gardening as winter sets in

Jeff Lowenfels
Fran Durner / Anchorage Daily News archive

Both my parents and my grandparents, as well as most of my aunts and uncles, forced bulbs that were supposed to flower in the spring to flower in the winter. I never gave it much thought, probably because everyone was doing it. I am not sure why more folks don't do the same thing today. It is such an easy thing.

I guess I did pay enough attention as a kid to realize there is really only one trick to forcing bulbs to flower early and that is to look up how long each particular variety of bulb needs to be chilled before it will bloom. With the Internet at hand -- and this column -- you can't fail.

Let's start with the bulbs that don't need to be chilled at all. These come from places where it is warm all year round and so low temperatures do not trigger a blooming period. Amaryllis are in this category. All they really need is a dormant period of eight weeks or so. Some paperwhite narcissus are in this group. Other paperwhites have been pre-chilled before they are sold. You will find both in stores during the next couple of months.

Amaryllis bulbs purchased from stores will bloom in eight weeks. These have been through a dormant period and are primed to blossom with the biggest flowers you can grow indoors. Those already in possession don't need chilling, but they do need that eight weeks of rest in the dark before you re-start them.

Paperwhites will bloom when grown either in soil or resting on pebbles or marbles. It takes anywhere from three to six weeks after you start them. Remember that some folks don't like their very powerful, sweet smell.

The more obvious forcing bulbs do need chilling. Tulips take at least 14 weeks of chilling and can go up to 20 weeks before they really need to come out of dormancy. Then it takes 2 or 3 weeks to actually bloom. So, if you want tulips indoors before they are available outdoors, you want to start forcing them ASAP. A second secret: All tulip tips curve and if you put them so they all curve "outward" toward the rim of the container, the eventual display will look uniform and professional.

Next up are daffodils (Narcissus). They need even more time to chill, 15 to 17 weeks to be precise. Get going. Again, add on 2 weeks or so of time so the bulb can develop a bloom after chilling. Some folks use different varieties of daffodils in the same pot to extend blooming. I like to use the doubles as this ensures lots and lots of blossoms. You can also mix tulips and daffodils.

Crocus are marginal outdoors in Southcentral Alaska unless we get great snow cover, but they are really easy indoors if you give them 15 weeks of chill. The big flowering varieties are the best to force, in my worthless opinion. Scilla, both blue and white kinds, require 12 to 14 weeks and Muscari, also known as grape hyacinth, need 15 weeks of cold and dark chilling. Galanthus or snowdrops require 15 weeks as well.

What does chilling entail? Once potted, store your bulbs where the temperature is ideally 47 degrees. Anything from 35 to 50 degrees will do, however. It should be dark and well ventilated. The soil is going to need to be slightly moist the entire period. You may actually see growth and be tempted to cut it short. Beware that if you do that your plants may blossom but they will be stunted and perhaps malformed. Who wants that?

Once your bulbs have been through the requisite chilling period, place them in light at 60 to 68 degrees as shoots grow and buds develop. Putting them under supplemental light after the stems are a few inches is in order. Once again, though not the point of the column, you can see the need for having a good plant light system when you live in Alaska.

Spring comes late here in Alaska. Coaxing a few spring flowering bulbs into action, early, is a great way to celebrate Spring with the rest of the country.

Garden calendar

Holiday cactii: Place in a below-55-degree spot where there is no supplemental light at night for 30 days to stimulate bud formation. Up against a window in an unlit room

Driveway and paths: Stake so you know where to take and to put snow.

Spider mites: Oh, oh. They are all over when the heat comes on in the fall. Either toss the plants or spray with an organic miticides.


Jeff Lowenfels' bestselling books are available at tinyurl.com/teamingwithmicrobes and tinyurl.com/teamingwithnutrients.


Jeff Lowenfels