Secrets to thriving, beautiful houseplants

Forget about the proverbial "green thumb."

By following a few simple rules, anyone can grow the most popular types of houseplants. Jennifer Brennan, horticulture information specialist at Chalet in Wilmette, shares 10 tips to houseplant success:

•Don't drown houseplants. Roots need air as well as water. Keeping the medium soaked at all times means certain death for most plants. Use your finger to determine if the soil is dry and then water thoroughly. Make sure the pot has a drainage hole. At least once a month, "leach" the pot by letting water run through it to prevent mineral buildup. The amount of water used for leaching should equal twice the volume of the pot.

•Give houseplants a rest. Nearly all plants need a rest in winter. Shorter days and lower light intensity trigger plants into a dormant period, resulting in slower growth and less need for fertilizer, water and heat. Keep plants cooler when light levels are low to prevent stretching for light. Stop fertilizing from the end of October to the end of February. Do not repot until right before the plant goes into its active growth period.

•Accept the loss of "temporary" plants. Many popular gift plants die in a couple of weeks. These "flowering pot plants" are only temporary residents and should be enjoyed as long-lived cut flowers.

•Give houseplants extra humidity. A centrally heated room in winter is as dry as desert air. To add humidity, use a humidifier, set up gravel trays to hold water, or mist plants.

•Treat insects promptly. Trouble will strike whether you are an expert or a beginner. One or two scale insects or mealy bugs are easily picked off, but an infestation may be incurable. Start with the least toxic control and proceed to stronger controls based on population size. First, use cold water to wash pests away. Next, use insecticidal soap and then horticultural oil. If these methods don't work, use a plant-derived pesticide. Finally, use a systemic chemical insecticide or a contact chemical spray insecticide.

•Group them together. Nearly all plants look and grow better when grouped together in a room, due to the increased humidity.

•Repot when necessary. After a year or two, many plants outgrow their containers, deplete the nutritional value of the potting medium, or require frequent watering. In most cases, the plant just needs to be repotted into a larger container or fresh potting medium. Most houseplants thrive best in pots which appear to be too small for the amount of leaf and stem present. It is a mistake to repot into a larger pot unless the plant is definitely "pot-bound." Signs include: stems and leaves grow very slowly even when the plant is fed regularly in spring and summer; soil dries out quickly, so frequent watering is required; or roots grow through the drainage hole.

•Choose wisely. The plant must be able to survive in the home you provide. Even an expert cannot make a shade-lover survive in a sunny window. Understand the location's light conditions and then choose an appropriate plant.

•Have the proper tools. Basics include a watering can with a long. narrow spout; a reputable brand of potting medium; pots with drainage, drip or humidity trays; liquid fertilizer; safe pest killer; soft sponge; and small pruning shears.

•Learn about the plant's specific needs. Matching a plant's natural growing conditions increases your success rate and extends the plant's life. Use a good reference book or pick up a plant fact sheet at Chalet, 3132 Lake St., Wilmette.