Save Your Frost-Tender Container Plants
It sounds crazy, but you can grow even the most exotic-looking plants by planting them in containers and protecting them from the winter cold. All you have to do is keep them alive until spring. In an ideal world, overwintering plants would be as simple as bringing them indoors for winter. In the real world, central heating systems rob indoor air of humidity, pests seem to appear from thin air, and watering is often neglected. The good news is that with a little practice you can overwinter almost anything.
Before the First Frost
Check each plant for pests and diseases and remove any unhealthy-looking leaves. If you spot any pests, spray the plants twice with an insecticidal soap or horticultural oil before moving them indoors to a sunny part of the house. Keep sun-loving plants in a room with south-facing windows or, better yet, in a sunroom. Keep shade lovers in a well-lit north-facing room to protect them from direct sun. Provide plenty of room around the plants for cleaning, maintenance and air circulation. Group plants together by their moisture requirements and put plastic saucers underneath to protect floors from spills while watering.
Most tropical plants can be grown through winter in a warm room. Aloes, echeverias and other succulents are happy in a warm room but should be watered only if their leaves start to shrivel. Tropical plants like bananas, bromeliads and elephant's ears also like to stay warm through winter, but prefer regular waterings. They also like humidity, and an occasional misting or bath inside a shower will prevent spider mites and parched leaves.
Plants that go dormant in winter should be kept in a cool room. These include Mediterranean plants like fig trees, lavender and oleander as well as South African plants such as red-hot poker and lily of the Nile. Dormant plants require half as much water as they would normally receive while they're growing.
Periodically wipe leaves with a damp cloth to keep them clear of dust and pests. If pests appear, spray leaves lightly with horticultural oil and look between the leaves, leaf undersides and stems to find any that are hiding. Container plants need little or no fertilizer through winter, but can be fed lightly right before spring arrives to coax new growth. After the last frost, slowly "harden off" the plants (let them adjust to outside temperatures) by moving them to a shady part of your garden every other day for a week. When the plants adjust again to outside light levels and temperatures, resume normal watering and feeding until fall.
That's it, so what are you waiting for? You can grow a desert of succulents and cacti in the cool Pacific Northwest, a Mediterranean resort in New York or a rainforest of tropical plants in Montana—in containers!
- Insecticidal Soap