Poinsettias are like Christmas budgets this time of year. Both are in the red. But what is that white flowering bush blooming freely now? Read on if you want to know. In the meantime, if you want to give inexpensive gifts with a personal flair, living plants that fit the personality of the recipient are ideal. However, be careful with your choices. There is a big difference between a succulent plant that might have romantic inferences and a spiny cactus that says something else! Poinsettias are blooming in some areas and not doing well in others.
Poinsettias especially in Kona, Ka‘u and Kohala are in spectacular color, but they do not like wet feet so are not always happy in East Hawaii.
Although mainland folks think of poinsettias as a Christmas flower, for us they bloom from November through March. Instead of being little potted plants, in Hawaii they become large bushes or even small trees when planted in the garden. The Poinsettia, taxonomically known as Euphorbia pulcherrima is indigenous to Mexico and Central America and was introduced to The United States by the first USA Minister to Mexico by Joel Roberts Poinsett in the 1820s.
As you drive around West Hawaii now you will see a close relative of Poinsettia with many common names. Euphorbia leucocephala is called the Little Christmas Flower, Snow Bush, or Snow on the Mountain. It is also called the White Poinsettia or Snows of Kilimanjaro. This close relative of the Poinsettia has similar cultural requirements. It prefers a sunny location and well-drained soil. Flowering is dependent on short days so don’t plant them near street lights or other artificial lights.
In massed beds, fertilizer application is important. An application of fertilizer in August should now be producing an abundance of white bracts. The plants need repeat applications of plant food in early spring, again in June and perhaps during mid-summer if there are heavy rains.
For best results, like Poinsettias, prune plants back in late winter or early spring after blooming is over
You’ll find that a compact plant will furnish more bracts than a plant with few leggy stalks. Prune the plants several times during the growing season. Nip the new growth tips back after they are 12 inches long, leaving four leaves on each shoot. Be sure to stop the pruning in early September, because the flowering buds are set in early October.
You will find that temperature is a limiting factor for a good show of flowers. If the night temperatures are much above 70 degrees, bud formation will be retarded. Freak periods of hot weather during this critical time may not permit buds to form at all. The best flower development is when the night temperatures range from 60 to 68 degrees. This year has seen somewhat warmer temperatures at lower elevations retarding flower formation, but upland regions have been ideal for a riot of color.
One problem to watch for now is mite damage. This little — almost microscopic — eight-legged creature is not an insect. You will need to have a magnifying glass to see it, but the damage is easy to spot. Leaves will have a fine salt and pepper dusty look. Dryer conditions are ideal for this pest. Spraying with a miticide will take care of the little stinkers. If you want to avoid sprays, spraying the leaves daily with the garden hose is helpful. This will also minimize whitefly attacks. Avoid sprinkling in the heat of the day or evening to avoid sunburn and fungal diseases.
Snow on the Mountain may be used in flower arrangements if the stems are treated to coagulate the milky sap and reduce wilting. As soon as the stems are cut, immerse the cut ends in hot water for about a minute. Then place them in cold water. Be sure that the steaming water does not damage the bracts.
An alternate method of halting the oozing sap is to singe the cut ends of the stem over a flame for a couple of seconds and then place the stems in cold water. For best results and longer lasting beauty, cut the branches about 18 hours before they are to be used in an arrangement. Store the cuttings in a cool, draft-free place during the waiting stage.
They are also easy to propagate from cuttings that may be grown in pots. If you want to experiment with this year’s potted plants, like the Poinsettias, don’t toss them out when they fade.
The plants will bloom again next Christmas season if you follow these tips. First, store the pots, plants and all, in an out of the way place. This treatment is intended to induce the plant to hibernate during the cool days while the shriveling top feeds the sleeping roots.
Only water the plant to keep it from getting bone dry. Avoid giving them fertilizer. Try storing the sleeping plants in the shady corner of the carport, lanai or garden.
Toward the end of February, tenderly awake the plants by cutting off any dead tips. You can grow the new plants in last season’s pots, but they will be happier if you set them in the ground where they can flex their roots better than in the confines of a pot. Plants may be kept to the height you desire, but without pruning they can reach 10 to 12 feet in height.
For more information, contact the University of Hawaii College of Tropical Agriculture and Human Resources (CTAHR) Master Gardeners at (808) 322-4893 in Kona and (808) 981-5199 in Hilo.