Unseasonably warm is the best way to describe this winter's weather up until the middle of January. An arctic chill from Canada blasted states from New England to the Deep South, surprising everyone, meterologists included.

Gardeners across the country found that recent record-breaking high temperatures kept their plants confused about whether to go to sleep or to bloom. Hopefully those plants remained asleep in their beds; otherwise damage control will be needed. Keep in mind it's still winter, so play it safe before filling the garden with new plants. Gardeners in our Zone 5 may wish to do a little houseplant maintenance until the weather permits working in the yard.

What to Look For In a House Plant
You can increase a house plant's chances for a long and healthy life if you choose a robust one at the start. Inspect plants closely before making your choice. Looks tell much about how the plant has been grown and readied for sale.
Choose those that are short and stocky rather than tall and spindly, and have abundant foliage growing right down to the top of the pot. Plants on which the first buds are about to open are preferable to those with full-blown blossoms because you will be able to enjoy their beauty from the beginning. A near-perfect plant has a thick, well-balanced array of leaves on a straight, sturdy central stalk. Just one stem of flowering plants may be in bloom, but many buds at different states of maturity indicate a long flowering to come.

Avoid plants with symptoms of pest infestation. Look at the undersides of the leaves for tiny spots that are lighter than the rest of the leaf: if you find any, you know that insects have been sucking the plant's juices to its detriment. Examine leaf surfaces near the tip of new growth for very small green, yellow, pink, black or brown insects called aphids, or plant lice. Check for spider mites: although they are too small to see without a magnifying glass, the damage they cause is not. They reveal their presence with speckled, whitish discoloration of the leaves. Check carefully where leaves and stems join for a white, cottonlike substance that is really a community of mealy bugs.
Once you are satisfied that all is well with the plants you have chosen, make sure they are properly wrapped if the weather is chill. Many house plants suffer quickly from cold, and even if your car is only three steps from the greenhouse door, your purchases will require protection in subfreezing temperatures.

Picking the Right Spot
To cope with the challenge of raising tropical outdoor plants inside your home in the winter, it is necessary to know, not guess at, the needs of each plant. Where climate and weather are variable, you will not always be able to provide the optimum conditions that will produce abundant flowers.

To come closest to this ideal, put your tropical flowering plants such as gardenias, crossandras and lantanas in the brightest, south-facing window in your house, and if the room is painted white and reflects light, so much the better. Make sure that the window you choose is the brightest without any overhanging trees, buildings or roof.

If all your windows are bright and you choose plants such as African violets, which do not need much sun, place the plants back from the window to keep them out of the direct rays of the sun, or draw a sheer curtain across the window. Dark walls may help in a situation like this, for the darker the paint, the less ligh is reflected. Conditions can differ so much in each house that you will have to do the best you can for each plant, and then rely on practical observation. If a plant does well, leave it where it is. If it does not do well, try another place, keeping in mind the plant's needs.

If there seems to be too much stalk and not enough leaf, the light is insufficient. Move the plant closer to the window glass. Be careful in winter not to allow leaves to touch the windowpane which can cause chilling at night. If this is not possible, find a sunnier spot. If the plant is getting too much light, drooping leaves will warn you. Find a shadier place, or draw the curtain across the window for part of the day.

When you have decided what kinds of plants you would like to grow, take stock of the conditions you can provide for them. Since house plants come from many different parts of the world, their needs for light, temperature and humidity vary greatly. But plants are adaptable, and many gardeners do not realize that their houses also are adaptable. Each house offers a broad range of microclimates. Even with central heating, different sections of a house will be far from uniform in temperature. A window sill on the north side is usually far cooler than one on the south. A south-facing window generally gets more light than one on the north. Kitchens and bathrooms are usually more humid than other rooms.
Despite many variables and the dangers of generalization in indoor gardening, one rule holds true for almost all plants: the more light a plant can be given without causing damage to its foliage and without depriving it of its nightly rest in the dark — the more likely it is to produce a rewarding abundance of flowers or a fine crop of foliage.

Robin Milliken is a Landscape Specialist and Master Gardener
The Master Gardener appears monthly in The Olathe Daily News.
© H&R Lawn and Landscape

Links to other monthly columns: