Your houseplants are shocked

The party’s over for the lucky houseplants lounging on our decks and patios. They spent a reasonably good summer out there, basking in the sun or the shade depending on their affinity for either. The early summer, cool and wet, kept their roots happy, and when it did get hot, it wasn’t too bad as Inland Northwest summers can go.

But now the sun is dropping lower in the sky and a few dreaded frosts have already hit: Any self-respecting houseplant should be inside the house by now.

But just like us, our vacationing houseplants are going to mope a bit as they transition back to their winter spots. A little planning on our part can keep leaf-drooping sulking to a minimum.

First, check to see if plants bring any hitchhikers in with them. The outside bugs aren’t particular when it comes to plants they go after. Houseplants are just as good as the roses when it comes to a free meal. The problem is when we bring the plants into the warm house, the bugs think its spring again and they start becoming active, while their cousins outside are hibernating or getting killed off by the cold.

Isolate any plants you bring in for a couple of weeks before you reintroduce them to the rest of your houseplants. Check carefully for signs of bugs under leaves and where leaves join stems. Apply insecticidal soap being diligent about getting into small crevices where bugs could be hiding.

If you brought your plants in before the big rain a few weeks ago, it may be helpful to give the leaves a washing. Put them in the shower and turn on some lukewarm water for a few minutes. Wipe the leaves to remove the last of the stubborn dirt. Leave the plants in the shower so the excess water can drain away. Skip applying any leaf-shine products as research has shown it can reduce the plant’s ability to transpire properly.

The toughest challenges of coming back indoors for our plants are the changes in light levels and warmer, drier indoor temperatures.

They were used to higher, brighter light levels outdoors, so when they come into the lower indoor light, they can go into shock. Think of it in terms of you feasting on Thanksgiving dinner every day and all of a sudden you have to survive on a salad. So review what kind of light your plants prefer and try to provide it for them. A fig (ficus) tree requires much brighter light than say a heart-leaf philodendron

Generally, an area with low light will get no direct sunlight, for example a window with a northern exposure. An area with medium light will have indirect sunlight and is typically close to east-facing windows or a few feet from a west-facing window. Areas with high light levels are brightly lit south or southwest-facing windows that do get some sun during the day.

In our northern latitudes, it is advisable to provide plants with medium and high light requirements some extra light to increase daily intensity and duration. The best way to do this is suspend a fluorescent light fixture a couple of feet above the plants and set it on a timer so that the plants get a total of 12 hours of light a day. Fluorescent light is preferred because it has a reasonable mix of red and blue light that plants need, and don’t generate heat that could damage the plants.

While specially balanced horticultural fluorescent lights are available, they are expensive. Ordinary fluorescent tubes will work almost as well and are much less.

Indoor temperature changes can also send plants into shock; temperatures 55 to 65 degrees are ideal. Be sure not to put plants near heat ducts or above baseboard heaters as the warm air will dry them out quickly.

Because most houseplants go dormant in the winter, the need for fertilizer and water are both reduced. Most plants can get by with a couple of heavily diluted fertilizer applications, or none at all, from now until they show signs of growth in February. Watering schedules will need to be monitored for a while to find the right balance between keeping the soil damp and not soaking wet. Dormant plants use a lot less water and excess water around roots can lead to root rot very quickly. For most plants a good rule of thumb is to insert your index finger into a pot down to the first joint. If the soil is dry at that level, then water.