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Houseplants: Staying Alive


The Bee Gees aren't the only organisms working on staying alive in tough times. Here in the Northeast, houseplants are heading into two months of hostile environmental conditions. A few tips from the experts will keep some special plants in shape until February, when daylight makes its presence felt.

Cymbidium orchid
Marilyn Shapiro, treasurer of the Greater New York Orchid Society and regional director of International Phaleanopsis Alliance, Inc., grows almost 300 plants in her Manhattan apartment. She got her first orchid in 1975 from a man who grew them above a brownstone in Greenwich Village. Her cymbidium lives near an open, cold window.

Her tips: ďIf the cymbidium is a standard or a miniature, give it a six-week cold snap because it likes to be chilled. A drop in temperature at night (to 35 or 40 degrees) from late October to Christmas encourages them to bloom. In September and November, they like to be fed so they can put on robust foliage. Around the holidays, you should be rewarded with blooms.Ē

Cane begonia (angel wing begonia)
Bernard Wiener, national representative to the American Begonia Society and membership director of its Delaware Valley Branch (PA), has grown begonias for over 30 years.

He says many canes grown under good natural light can grow 3 to 5 feet tall. Itís best to cut the oldest canes close to soil level in winter and leave the current year's canes alone, as he just recently did. Heíll propagate the cuttings for spring.

ďThe pruning is done so you have more chance for the flowers to form on the new canes. The flower is what you aim to get if you grow it properly. During winter months, they donít do any productive growing. The trick is to maintain them and keep them alive until the light starting in February comes, whereby you can get better growth on the plants.Ē

He says winter is a difficult time for the grower to get any real evidence that the plant is thriving. You have to keep it watered enough so the roots donít dry up, but not so youíre pushing it with too much water. In winter, most plants go into dormancy because they do not have good natural light. If you want to push them into more vigorous growing, you have to supplement the light.

Light and water: You canít have one without the other. Best window is a southern exposure with afternoon sun. The plant will tell you if itís growing properly in that exposure if the canes increase in size (it needs this light to do that). If the canes are increasing in height, itís okay to grow it naturally and water more frequently. If you do not have afternoon sun, cut the water back. Do not fertilize it.

Temperature: A plant in the winter time likes the same as a person: 70-72 degrees.

Humidity: The worst thing for a plant is to be growing in a hot house with a high temperature. Humidity is reduced in high temperatures. Increase humidity around the plant by placing pebbles in the saucer with water below the level of the pebbles. ďItíll make the plants happier,Ē he says.

Water: Use a wooden lead pencil in the way of baking a cake. When you want to know when the cake is done, you put a toothpick into the batter and if it comes out moist it needs more time in the oven. Stick a pencil into the soil in the middle of the pot and go down two inches. If the pencil comes out the same color that it went in, itís indicating that itís dry. Then you water it properly until the water runs through the bottom hole of the pot.

Kathryn Andersen, director/secretary of the North American Clivia Society, says donít overwater clivia because the roots will rot right off. Just think: in a normal summer they can live outdoors in shade with the amount of rain that comes down.

If you overwater and rot the roots, know the signs: yellow foliage, the plant falls over and easily comes out of the pot. If roots rot, scrape off the slimy parts, dust with a fungicide, and put it in sand to re-root. Sometimes the roots in the center of the pot die while the roots along the outside are plentiful. Take off the bad roots and repot with fresh soil.

Andersen says: ďFeed with dilute fertilizer once a month from March and clivia will probably bloom in June after over-wintering in normal house temperatures. If you want it to bloom in March or April, put it in a very cold place like 45-55 degrees; stop watering it in October or November completely and donít water until January. It goes through a dormancy. The leaves will mostly remain and not die back. Technically theyíre a bulb but just look like big fat roots. (Cliviaís six species are in the amaryllis family.) Let dry between waterings.Ē

Light: In household light in winter, although not dormant, the plant will not grow so low light wonít make much of a difference.

Ray Rogers, coleus aficionado, plantsman and author, plays at Atlock Flower Farm in Somerset, New Jersey, among 150 coleus cultivars watching for promising sports. His dedication to coleus has led to a book, Coleus: Rainbow Foliage For Containers and Gardens, breeding, and starting a coleus society. Many coleus, he says, are at their peak in February, so you only have to keep them well for two more months.

Hereís how: Think sun, warmth, and water.

Give coleus as much sun as possible, preferably a southern window, but not right up against it where the leaves will freeze at night. Minimum night temperature: 55 degrees.

Water slightly. ďIf you think you are keeping it moist enough, you are probably over-watering.Ē In a sunny and warm spot, itíll take more water. If itís too dry, itíll wilt. If the soil is too wet, the roots will rot and thatís the end.

Leaf loss: Itís normal to cast off the oldest leaves; all plants do, even evergreens. But if a lot of leaves all over the whole plant turn brown and crinkly, it is on the verge of death.

Look at your over-wintering plants as stock plants, as a grower would. Cut them back in April and root the cuttings in sand. (Atlockís gorgeous stock plants in the greenhouse now were cuttings last April.) After the last frost, plant them in the garden. Dig and pot them up in a container in August and cut them back. Coleus grow fastest in August and September, so never fear. In October, chop them back hard and bring indoors.

They need at least one month of dormancy before you wake them up and one month to blossom. Rogers has always timed his to bloom in March for exhibition at the Philadelphia Flower Show. If you want yours to bloom for Christmas, you need to dry the leaves up by mid October and in September, begin to withhold water.

But itís too late for that. A lot of amaryllis donít need to go dormant and if they donít go dormant, theyíll bloom when they feel like it, often two or three times a year. ďItís a big mystery for some people. When they start looking terrible, put them in a dark, cool place but not humid. Keep them bone dry.Ē

American Begonia Society: (great photos to help identify your plant)
Greater New York Orchid Society:
North American Clivia Society:
Ray Rogers:

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published December 01, 2008

Photos to enlarge

Bernie Weiner over-winters cane begonias, including Looking Glass, in a sunny window. Photo courtesy, Bernard Wiener

Cane begonia's coveted blossoms

Ray Rogers in the greenhouse with 'Charity,' a scented geranium

Ray's playground and toys - coleus sports

Feline Ivy and 'Dark Star' coleus

Evergreen Cybister amaryllis

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