Logee's Greenhouse

Flowering short-day bloomers is rewarding, as if somehow you’ve cheated old man winter out of his gloom and brightened your space for a taste of springtime. Yet, winter is the leanest time and often the most challenging time to bring plants into flower.

Remember, the process of creating beauty takes place months earlier. Winter flowering plants usually fall into three groups: those that form buds during the short day length; those that prefer cool nighttime temperatures of fall; and those plants that flower year-round even under the low light of winter. Once you’ve been with these flowers in the dead of winter, we are sure you will want to continue that trend for next year.

The one distinction between short-day bloomers and other winter performers is that short-day bloomers only depend on the length of darkness that they receive in a day. Other winter bloomers like Jasminum Polyanthum are not dependent on the day length as much as cool nighttime temperatures.

Some short day bloomers that we like are Cantua buxifolia, Coleus thyrsoideus, and Calliandra haematocephala. All are dependent on the day length for bud formation, which begins in October, or once we have gone below 13 hours of daylight. Although, many tolerate cooler temperatures, they are not dependent on it.

Cantua buxifolia or the “Sacred Flower of the Incas” is always a welcome sight and with a little attention to culture is a sure bet for winter color. First, don’t prune after early June. During the heat of summer watch for spider mites, which have an affinity for this plant. Grow them in the sunniest spot possible. They also can tolerate dryness. A slight wilt between waterings does no harm and, in fact, may help. In early fall be sure that the plant is kept in total darkness from sun down to sun up. By the time December rolls around the buds will be visible with two-and-one-half inch tubular flowers dripping from its cascading stems; they will last from January to May. We grow this plant in a standard or tree form or as a mounding bush in the potted container.

Coleus thyrsoideus can be a little tricky to bring into its full glory. Cuttings need to be started no later than late spring before the heat of summer has arrived. In the summer, pot them up and grow outside in a sunny spot. They have trouble with long spells of heat and, at this time, growth can be slow. The foliage can become yellow or light colored regardless of the amount of fertilizer given. This is a time to maintain them, for as the weather cools, they green up and start growing once again. It is important to do the last pruning, or pinch, by the end of August. Grow them in full sun. Give them a normal day length, that is no light from sun down to sun up, and grow at 65°F minimum temperature. Bud formation will be visible by early December with flowers staying through March into and early April.

Finally, Calliandra haematocephala, “the red powder puff” is an excellent winter bloomer. The trick to blooming this plant is to perform the last pruning in early to mid August. It also needs a normal day length, but is not as sensitive as the others. Keep it in an out-of-the-way spot that has a sunny exposure. The growth that forms in September and October will have small buds along the leaf axis, which by November will open continuously into March. The mesmerizing effects of its puffballs of brilliant red are a perfect showstopper for indoor winter fun. Prune hard once it has finished flowering.

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