Gardening Topic for March 2005
Creating a Nurturing Environment for Your Houseplants

Provided by the Western Massachusetts Master Gardener Association
www.wmassmastergardeners.org.

What exactly do houseplants need to grow well? There are many factors, but perhaps the most important are good light, adequate water and humidity, heat without extreme temperature fluctuations, ventilation without drafts, and adequate fertilization. Balancing all these factors is most important. For instance, plants in a cool room need less water, and most plants need less fertilizer in the winter. Also, light and water requirements vary greatly with different types of plants. But let’s break it down.

Good light means different things for different plants. A Spathiphyllum (peace lily) will grow well, and even produce lovely white flowers, in moderate to low light. Many a Schefflera (umbrella plant), Dracaena (corn plant), Philodendron, Aglaonema (Chinese evergreen), Chlorophytum (spider plant), and fern will also do well in fairly low light. But some of these plants also come in variegated forms, with white, yellow, or pink markings. If you have one of these, it will need more sunlight than the plain green variety. Also, remember that succulents such as Crassula (jade plant), Sedum morganianum (burro’s tail), Kalanchoe tomentosa (panda plant), aloes, and cactuses need much more light than the aforementioned plants. Which brings us to the next issue – watering.

All plants need water, but when and how you water makes a big difference. Many people have a single watering schedule for all their plants. Although this may seem efficient, it is not the most effective method. Plants with thin, serrated, or feathery leaves usually need the most frequent watering. But that doesn’t mean they need to be watered every day, or even every week. The size of the plant, whether it is in a clay or plastic pot, the temperature inside your house, and whether the plant is in a warm spot or on a cool window sill all make a difference. When you notice a plant drooping slightly, that’s the time to water. The plant will not go into shock over a slight wilt, and it’s the best way to know for sure that the soil has dried out enough for a good watering. After a few weeks, you will be able to detect what each plant’s watering schedule should be, and you can water accordingly after that. Chances are that several plants will end up on the same schedule, which will make your life easier.

But the cactuses and succulents will be on a different watering schedule than your typical tropical indoor plants. In the winter, in a room that is not overly heated, these plants can easily go for a month or even two without watering. The signs of thirst to look for here are a slight shriveling. The soil will also pull away from the edges of the pot. When you do water, make sure you soak each plant thoroughly, so that water runs out the bottom and fills the saucer. After some time has gone by (anywhere from a few minutes to a few hours, depending on the size of the plant), discard any water left in the saucer, and you’re good until the next watering. However, if you notice that water ran out and then the plant soaked it all up rather quickly, that plant may still need more water. Keep watering until it’s saturated, knowing that your plants’ roots have soaked up all that’s needed for now.

Humidity and ventilation are generally harder to control than light and water. Most homes in the Northeast are too dry in winter, and cold air can rush up stairwells and under doors without warning. Nonetheless, it doesn’t hurt to try and protect your plants. You can use a humidifier in the room where most of your tropical plants are. Or put several plants in a tray that has a layer of pebbles on the bottom to which you have added water. You can also try misting plants in winter, but it may not be worth the effort, as the effects are generally short-lived. Don’t put plants near radiators or other heat sources, and avoid drafty areas. You want circulation, but not gales.

Most houseplants like temperatures in the 70s during the day and in the 60s at night, although some are fussier than others. You will soon find out if your home is too warm or too cold for certain plants. And you can also try moving a plant to another room to see if the conditions are better there.

A good all-purpose houseplant fertilizer, in liquid, powder, or tablet form, helps keep plants growing. However, most houseplants in the Northeast need little or no fertilizer from November through February, when light levels are low and they are not actively growing. But as the days start to lengthen, begin fertilizing at the recommended strength. Keep up that routine during the spring and summer, and then taper off in the fall as the light fades. Also, younger plants usually need a little more fertilizer than older, more established ones. But don’t overdue it, as plants can burn with too much fertilizer. As with watering, don’t kill them with kindness.

There is so much more to be said about houseplants, but perhaps the best advice is to learn by doing, by reading, and by talking to gardening friends. When buying a plant, it is best to purchase it at a reputable plant store or garden center. The people working there generally love plants and are knowledgeable about them. And if you have problems later on, you can always go back and ask them for help.

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Provided by the Western Massachusetts Master Gardener Association