Growing Concerns 486: Bring plants in for winter, pansy marketing


Houseplants that summered outdoors don't harbor  house-infesting insects 

I have some questions about bringing plants in for the winter. What about pests in the soil? What about pests on the plants I may not be able to see? What can I do to help them survive the transition? Should I fertilize them or hold off? - Louise -


Remember those real life horror films when a science channel introduced prime time TV viewers to the microscopic mites that live at the base of the human eyelash? Do you stil feel itchy when you recall that? If so, you may not find it easy to accept this advice, which is to stop worrying about pests if the plants look healthy and were growing vigorously when you brought them in.

Every plant has bugs. Live plants involved in experiments on the space shuttle might be exceptions but all the rest are certainly hosting at least a few insects or microscopic troublemakers. Plants can't escape their parasites any more than people can. We're free-ranging, living things so we can't be sterilized.

We and our plants thrive if given a healthy environment. Our systems are able to wage war against pests, keeping them in check by loading cells with antagonistic chemicals, populating blood or sap with defensive microbes, keeping some at bay with thick coatings until they can be rinsed off, and just plain outgrowing some, shedding them with old tissue. We are almost always dealing with some greeblies but most of the time there are too few to do more than psychological damage.

Given charge of a person, we look them over, decide if they seem clean and healthy, then proceed normally to keep them that way. We don't give antibiotics or other drugs "just in case" because we know that dosing a well person with those can make them less effective if sickness actually comes. The same tatics apply to your plants.


Shower 'em with clear water

Rinse them off well, if only to get a true measure of their healthy color but also to make up for any lack of cleansing rains. Rinse off the pot, too. Don't think about what's in the soil or too small to be seen -- if the plant is growing well, it's got any such hitchhikers in check. Those pests are not using the plant as a Trojan horse to invade your home. They are living with the plant because they can, and it's very unlikely they will be able to populate any other niches in your house.

In fact, your home environment may be the death of them, as it can be for plants. Focus your efforts there, at the transition you mention.


Cool, bright and no fertilizer

Keep your plants in the brightest possible light, suplementing if necessary with grow lights or afternoons out on a shaded porch when the temperature's above 55. Be very careful with water as potting soil may at first dry out in the parched indoor air but then need water far less often than when the plant was oudoors photosynthesizing more rapidly.

As days shorten and the plant's growth slows, stop fertilizing -- the general rule is to withhold fertilizer from November through March unless the plant is under supplemental light and actively growing.

Look your plants over well every time you water them turn them to the light or rinse light-blocking dust off their leaves. If you see color changes or other signs of reduced vigor, change the light or water before the plant goes downhill and loses control of its ever-present pests.


Short reports

Read between the lines of clever pansy marketing...

...Any pansy can overwinter and be there to add spark among the spring-blooming bulbs next spring. "People have definitely heard the ads for the 'Icicle' series pansies," says Erma Rhadigan, retail manager at Ray Wiegand's Nursery in Macomb Township. "But they're wrong to think that's the only pansy they can plant in fall, or that it's significantly hardier. I've planted pansies of all kinds in fall for twenty years at my home in Macomb Township, and when I grew perennials professionally for many of the garden centers in the area. Unless it's a really terrible winter, they all make it through. Sometimes they bloom during January and February thaws, too!"

So don't be picky -- if a good looking pansy or Johnny Jump-up at the garden center catches your eye, buy it and plant it!


Stay a step ahead of rabbits...

...If it's green during winter or has particularly tasty buds and bark it'll be fodder for bunnies, especially this year when rabbit numbers have been prodigious. Put chicken wire fencing around pansy plantings and protect the first two feet of small bushes and the trunks of trees -- that's the reach of a cottontail standing on packed snow. This is especially important around rabbit favorites such as burning bush, euonymus, Viburnum bushes and fruit trees.


Green thumbs up

to gardeners who take their love of nature into the voting booth by questioning candidates' positions on environmental issues. Although the U.S. has fallen far behind many countries during the last twenty years in stewardship of the land, air and water, the nation's growing number of gardeners could bring us back to the top.


Green thumbs down

to Daylight Savings Time, for taking away an hour in April when a gardener truly needs ever minute, and withholding it until late October when it's often too cool and dark to be of much use. How aggravating, too, when the time changes saddle many of us with days of jet lag during two of the most important gardening seasons!


Originally published 10/19/02