Houseplants--Your Winter Garden

Martie Young
Adams County Master Gardener

Here it is, January. Christmas is over, the decorations are put away, the greens have dried and fallen all over the house. Itís time for some different greenery--some that will last longer than the Christmas tree. If youíre like me, you may need a trip to the plant store to assure yourself that there are still plants that arenít hidden by snow that will bloom in your house and make you think of spring.

There are many such plants to choose from. Some are familiar such as African violet, philodendron, spider plant, dracaena, and Chinese evergreens. Others may be not so familiar like Flamingo lily (Anthurium spp.), Flowering maples (Abutilon spp.), Citrus, and Gardenia.

In this weekís column, we will review some general guidelines to follow for keeping your houseplants growing vigorously throughout the winter months. Next week, we will take a closer look at some specific houseplants to buy.

Lighting

If you choose a plant that you havenít grown previously, be sure to ask for directions and the best conditions for the plant. In general, the plants that bloom inside need bright light. This can mean a minimum of 4 hours of direct sun (citrus, gardenia, flowering maple, oxalis, and hibiscus) or it can mean bright but indirect sun (Kafir lily, hydrangea). If you have grown African violets successfully, which means that youíve gotten them to bloom, you already know what they need (fluorescent light or an east or west window during fall-spring). The plants that come as a dish garden generally will survive on less light. The dish garden combinations are not necessarily compatible, however. You may not be able to get an African violet to bloom unless you remove it and plant it separately.

Temperature and Drainage

Many plants prefer cooler temperatures than their owners. Citrus, Kafir lily and gardenia require cool nights of 50 to 60 degrees to set flower buds; orchids like 65 to 75 degrees. All plants do better with lots of humidity. To improve the humidity for plants, set them on trays covered with stones and water the trays. Always provide a pot with a drainage hole.

Pests

Insects may be a problem. Common plant pests are mealybug (white and cottony and easy to identify), aphids (small insects which can be green, black or brown), scale (an armored bump on a leaf or stem), mites (silvered foliage and/or webbing), fungus gnats (tiny flying insects that live in the soil but sometimes are found throughout your house) and whitefly. Always buy new plants from a reputable source and keep a close eye on them so you do not introduce any new pests to your other plants. There are insecticidal soaps and stronger insecticides if a pest problem develops. Remember, be sure to read the directions and use the least harmful method. Remember, pesticide on a flowering plant can sometimes injure the flowers. If pests get out of control, it may be best to throw away the plant..

Water and Fertilizer

Proper watering may be the most important factor in plant health. If you have plants in low light and/or low temperatures, less water is needed. Monitor by sticking your finger down into the soil or lift smaller pots to check the water weight. Itís important to allow soil to dry out between waterings. Discard any standing water as soon as possible.

Martie Young is a Penn State Master Gardener from Adams County.Penn State in Adams County is located at 670 Old Harrisburg Road, Gettysburg, PA 17325, phone 334-6271 or 1-888-472-0261.

Penn State is committed to affirmative action, equal opportunity, and the diversity of its workforce.

 

Houseplants - Your Winter Garden

Last week, we took a look at some general guidelines to follow to keep your houseplants growing successfully through the winter months. Today, we will take a look at some specific plants that bring the garden inside. Depending on your specific house conditions, here are some plants you might want to try:

Oxalis

Oxalis needs well-drained, loose soil (potting mix with added perlite) and 4 to 6 hours of sun a day. During the growing season, feed oxalis every other week with all-purpose, balanced houseplant fertilizer. To avoid spider mites, cut oxalis back to soil level when bringing indoors. Mites flourish in overly dry conditions. Repot oxalis every year or two and divide the tubers or fibrous roots.

Citrus

Citrus trees thrive on container living with their shallow roots. They need 4 to 6 hours of sun, good drainage, regular feedings and plenty of water. While the plant is indoors, water only when the top inch of potting mix dries out. Citrus trees flower in late winter or early spring and fruit ripens 9 to 18 months later. Check plants for pests such as mealybugs and spider mites; spray with horticultural oil or insecticidal soap, if necessary.

Bromeliads

These plants like moderate temperatures, bright indirect light, an occasional breeze and a deep drink now and then. Some bromeliads donít require soil; they need only a stick to cling to. Those grown in containers should have a pot no larger than necessary to stabilize the plant. A coarse, quick-draining, acidic potting mix, such as a homemade mix of equal parts perlite, pine chips and commercial potting soil, is suitable. Dry air is the biggest problem and can be solved by setting potted plants on pebbles in trays of water. Misting leaves helps also, and grouping bromeliads builds their own humid microclimate.

Ivy

Ivies adapt to a variety of conditions. Plant in an ordinary soilless potting mix, with extra perlite for drainage, water only when the mix is dry to the touch, and spritz the leaves with water frequently to foil spider mites, one of ivyís few pests. Feed sparingly, as much as monthly in winter and bi-weekly in the growing season. Light pruning helps to increase branching.

Orchid

To grow orchids, you must adhere to one basic rule: only grow orchids that are suited to the conditions you can offer them. The realities of available light, air circulation, humidity level, and temperatures-- both day and night--are most important. Before shopping, evaluate your windowsills. A low-tech way to rate your light is to observe the shadow your hand makes when placed about 6 inches above the plantís eventual position. A crisp shadow means the light is high; a soft one means itís low to medium. No shadow, no orchids, please. Even low-light orchids need light at least eight hours a day.

Beginners should try phalaenopsis; it does not demand a lot of light and requires average household temperatures.

Christmas Cactus

Plants we know as Christmas Cactus donít all bloom at Christmastime. They are long-lived perennials that require very little fussing. They need bright, but indirect light, moderate water, and a well-drained, porous planting mix. In summer, theyíre happy outdoors in the shade of an arbor or tree. They are long-day, short-day plants that is prompted to set buds when daylight diminishes in the fall. In rooms where lights are turned on at night, the plants fail to get the message. Keep them in unlit rooms at night until buds appear at stem ends. Feeding also affects bloom. They do fine with a balanced 15-30-15 liquid fertilizer, applied half-strength in March or April and again in June. In September a full dose of zero-nitrogen bloom-inducing fertilizer will harden off new growth. Misting the plants controls spider mites. It is not necessary to repot for many years.

African Violet

Producing flowers requires lots of bright light. East-facing windows with full sun in the winter are best; west or south-facing windows need sheer curtains in summer to keep leaves from scorching. Temperatures can range from 60 at night to 70s during the day. Donít let plants dry out or become waterlogged. Water thoroughly with room-temperature water. Never leave the pot in water more than half an hour. Using cold water or spotting the leaves with water will affect the plantís health. Continual blooming requires nutrients: a quarter teaspoon of soluble powder fertilizer per gallon with every watering.

Happy winter gardeningóitís just as much fun as any other type of gardening.

Read other articles on house plants

Read other winter related gardening articles

Read other articles by Martie Young