You’ve kept your outdoor plants going through pleasant to hot and dry weather, but with days and nights getting downright chilly, you’re thinking about moving some of them indoors.
Just as there are ways to ensure success when planting, there are ways to ensure your plants will overwinter indoors happily. Which brings us to the first tip: If a plant has been unhappy outdoors, bringing it indoors to fuss over is probably a wasted effort. Let it go and concentrate on the healthy plants.
But even healthy plants can host lots of unwanted critters. Three area garden centers agree the biggest mistake home gardeners make when bringing in plants is failure to inspect and treat them for bugs, spider mites and more. Rose Long, a buyer at Reed’s Nursery in Valparaiso, Ind., recalled seeing “a cloud of white flies from my own plant about 10 years ago. You don’t want that.” She relies on Bonide systemic granules to kill white flies and their eggs, along with other little hitchhikers.
Some gardeners say to lift the plant from its pot, shake off loose dirt from the roots, and spray with insecticide more than once. But Eric Bobey, co-owner of Deer Creek Nursery in Crown Point, Ind., said this just stresses the plant, poor thing, and who wants to do that? Bobey said to simply spray it with soapy water, rinse, and bring into the house to dry -- sort of like washing the dog, but a lot less messy.
Larry Karp at Karp’s Garden & Feed Center in Hobart cautions against using a systemic insecticide on herbs and other edibles. For those, look on the label for safe alternatives. Whatever you use, be sure to look under the leaves as well as on top,” since some insects like to hang out there just to confound you later on.
The magic moment
Just when should you bring in the foliage and flowers? It depends on the plant. Bobey recommended housing common varieties by early October. “They’re not cold hardy; one cold night and there goes your houseplant.”
Well, sure. But surprise: Some bulb plants, such as gladiolas, need to stay outside until after the first frost. Then, said Bobey, “Dig them up, dry them out and store in a cool, dry place.” Bringing them in sooner means the foliage won’t have been killed by frost and will sit there and rot. Not good. Knocking down the foliage allows for dormancy, and “Most plants need to go into dormancy,” said Long.
An exception is Silver Drop eucalyptus, which grows rapidly in winter in full or part sun while other plants are moodily adjusting to the move.
Some bulbs, like daffodils and tulips which bloom in early spring, are planted now, in the fall. But here’s Karp’s rule of thumb: If bulb plants flower in summer, dig them up and store them in spaghnum peat moss or vermiculite, which helps keep moisture away from the bulbs. Tropical plants are another matter. Your beautiful hibiscus needs to be safely out of the weather before a hard freeze, said Bobey. Your unheated garage isn’t warm enough, either; the temperature should not fall below 50 degrees.
Eat, drink, sun
As for common foliage and flower houseplants, a common error is overwatering them. Simply check soil dryness by sticking a finger into it, said Long. Karp said potted plants are usually drained pretty well and need watering just once a week in winter. “I recommend bringing plants in house in a potting mix,” said Karp. “You don’t have that overwatering problem as much as with potting soil, which has dirt in it and isn’t as forgiving as potting mix.”
Long said signs of underwatering are brown, dry tips on outer leaves; overwatering causes inner leaves to turn yellow.
The days grow shorter, so “You’re bringing plants from extreme sun outside to low or almost none inside,” said Long, so try to place sun-loving plants at south-facing windows; plants liking shade can go to west or east windows. If it’s still not enough sun, consider a grow lamp. Bobey said four or five hours of light are needed each day, whether from a natural or artificial source.
Finally, fertilize. “The faster it grows, the bigger it is, the more it will need fertilizer,” said Karp.