Amaryllis and Christmas Cactus

As the Christmas season approaches, many of you will be thinking of ways to brighten your interiorscapes. One of the best ways, of course, is with the use of flowering plants. 

First is the amaryllis (Hippeastrum). Ordinarily a spring-flowering tropical bulb, this showy bloomer brightens up any room when forced to bloom indoors. No cold period is required for these bulbs as is required for some others.

Amaryllises grow from large bulbs, some nearly as big as a grapefruit and weighing more than a pound. Even on average-sized bulbs, blooms are eight to ten inches across. The plant produces three or four flowers at a time atop each thick one-to two-foot tall stem. Usually, just as the first flowers fade, the bulb sends up a second flower stalk. 

Some bulbs are identified by color only-white, pink, red, orange, or striped. These are not as hardy or large or as long-lasting as the vegetatively propagated ones, with fancy names  such as Appleblossom, Beautiful Lady, Fire Dance, Scarlet Admiral, and White Giant. 

When potting up amaryllis bulbs, remember that they love tight quarters. If the pot is too big, you’ll likely get nice leaves but no flowers. It is best to use a pot that is no more than two inches larger in diameter than the bulb. The bulb itself should be left about half way out of the soil. The roots grow from the base of the bulb. Fill the pot with a well-drained soil mix and then water. 

The first sign of growth is the flower bud itself-the leaves don’t usually develop until the flowers are opening. Once the large, tear-shaped flower bud is visible, the plant should receive a feeding once a month, enough water to keep the soil barely moist, at least three to four hours of sun, and temperatures in the 70’s during the day and in the 60’s at night if possible. 

If you would like a spectacular show in your home during Christmas, force some amaryllises. Visit your local nursery or garden center or favorite online plant source and get started! You can also purchase prepotted bulbs at various locations. 

Next is the Christmas cactus, Schlumbergera bridgesii, also known and grown for its bright colors and profusion of flowers.

If you buy a Christmas cactus plant in bloom, put it in a bright spot out of direct sun, as too much light will make the leaves turn yellow.  Average household temperatures are fine.  Avoid drafts from heater vents and fireplaces. Keep the soil barely moist and feed the plants every other week with a good, all-purpose fertilizer.  The plants will stop blooming in late winter or early spring, but it is best to continue to give them this care until the fall.  

It is not particularly difficult to get the Christmas cactus to bloom every winter, as long as it is given some special attention during its rest period, from early September until flower buds form.  It flowers in relation to day length and night temperatures during the rest period.  When the fall nights are in the 50 to 60 degree range, flower buds will form regardless of how many hours of darkness the plant receives. 

But if the night temperatures are greater on average than 60 degrees, the plants will require at least 13 hours of uninterrupted darkness every night for about six weeks; either put the plants in an unused room or cover them with a dark cloth at night if they are in a lit room. Remember: the plants will still need bright light during the day. (A plant left outside until frost is likely to have had enough cool nights to have formed flower buds by the time it is brought inside).  

During the fall (October), while the buds are forming, stop fertilizing them and water them very sparingly-just enough to keep the stems from shriveling.

Once the flower buds appear, the night temperatures and hours of darkness no longer matter.  Place the plant in a bright spot and enjoy watching the buds open.

The Christmas cactus flowers best when it is rather pot bound, but if it becomes too crowded for space, it won’t bloom well.  So, when you notice a loss of flower production, or if it’s been several years since the plant has been repotted, move it up to a slightly larger pot in the spring before you set it out in the garden for the summer.

These cactuses can be easily propagated from stem tip cuttings taken any time of the year.   

Tim Lewis is a Georgia Green Industry Association Certified Plant Professional, gardening writer, and former Perry High School horticulture instructor. He can be reached at (478) 954-1507 or timlewis1@windstream.net.