Many gardeners who have sunrooms, light gardens or wide windowsills in their houses overwinter plants which are used outdoors during the summer growing season. One reason for doing this is to save money by not having to purchase so many plants in the spring, although this doesn’t seem to work for me as I rationalize that I have saved so much money that I can buy all those other plants that I would also like to have!
Another reason for bringing plants inside for the winter is to add to the collection of indoor plants. I spend countless enjoyable hours during the winter tending my indoor garden and in late winter and early spring I enjoy beginning the whole process of taking cuttings from these overwintered plants so that I have plenty for my outdoor garden when the growing season does arrive.
Some plants are easy to bring indoors because I simply take slips from those growing outdoors. Coleus, German ivy and the perillas are examples of plants that root easily and very reliably either in water or in a planting medium. I take several slips just in case one or two fail to root, and I usually put them into a vase of water in the sunroom and leave them until I have time to pot them up. By then they will be well rooted. Before I begin the process of bringing plants indoors, I give the sunroom a good cleaning, during which I examine all the plants already in the sunroom for any signs of insect pests. Then I set a rule that anything that comes inside must be insect free.
To achieve this I have a bucket of insecticidal soap solution on hand and I swish the slips around in the mixture before I bring them inside. Some plants, such as geraniums and members of the plectranthus (Swedish ivy) family, do not root as reliably as coleus so I usually bring in a small piece of plant which has some root attached. The parent plants will generally have grown too large to be brought indoors but a small piece will soon grow and produce lots of slips by late winter. These plants are closely examined for insect pests and given a good bath in the insecticidal soap solution. I pot the plants up in a soilless mix on the surface of which I sprinkle some all-purpose insecticidal dust such as that used on potatoes and cabbages in the outdoor garden. This ensures that fungus gnats will not establish themselves in the planting medium.
There also are those plants which are really houseplants but which have been put outdoors during the summer. In my garden that includes my Cuban oregano (actually a plectranthus), my scented geraniums and the pots of streptocarpella. The plants are cut back and any damaged foliage removed. They are also given an insecticidal soap bath and the soil surfaces receive a dose of insecticidal powder. If any of these plants appear in need of repotting, this is an opportune time to do it.
The final group of plants to bring indoors is my collection of “exotics” that I grow in containers in my outdoor garden: my many oxalis, my calla lilies and the Peruvian daffodil. These plants are brought inside in their pots – after the prerequisite shower and powdering – so that they can be gradually dried off and stored for the winter. This drying-off process usually takes a month or so. I simply stop watering them and they gradually die back at which time I store the pots away in a cold, dark place.
Bringing plants indoors for the winter is a good gardening task for a warm, sunny September day. By taking a few precautions, no insect hitchhikers will accompany the plants indoors, and by ensuring that healthy slips, cuttings or pieces of plants are chosen and treated correctly, no member of your plant collection will be lost in the process.
– Albert Parsons writes from Minnedosa, Manitoba