How to bring your plants inside so they survive the winter
No matter where you live, you can enjoy the lush, colorful plants of the deep tropics in your garden — at least for the warmest months of the year.
Yet all is not lost as cooler temperatures move in. The good news is that, given the right conditions, most tropical plants will overwinter inside, patiently waiting until they can safely be moved outdoors again next spring.
Although there are plants suitable for every growing region, tender tropical plants won't survive in temperatures below a certain level.
Common plants in that category include Rex Begonia, ferns, cactuses, bromeliads, succulents and even small citrus trees. Before outdoor temperatures get too chilly, these plants need to move indoors. Plants that are moved when indoor temperatures more closely match the conditions outside better handle the transition.
The bigger the difference, the greater the shock on plants coming inside, so try not to wait until the first frost or freeze warning before moving plants.
Before your plants settle in to their new winter home indoors, there are a few things you should do.
Ÿ Inspect for pests. If insects or bugs are living on your plants while outside, they'll make the trip indoors. That's why it's a good idea to inspect each plant first. Some bugs and insects are so small and hide so well, it can be difficult to spot them. An easy and effective control is a stiff blast of water. Don't make it so strong that you damage the plant, but it should be forceful enough to knock any bugs out of their hiding places. This simple task is well worth the small amount of effort. A pest-free plant inside over winter will improve chances of survival and make your life a bit easier, too.
Ÿ Repot your plants. After a full season or more of growth outdoors, the root mass within pots likely has expanded to fill the space. Once roots grow to the confines of the container, they continue to grow in whatever direction they can. But the longer they're forced into this behavior, the more difficult it becomes for the plant to thrive, let alone take up water and nutrients. So as you prepare your plants for their new environment, take the time to remove them from their existing container to inspect the roots. Look for light-colored, nonodorous, healthy-looking roots that have not yet formed a circular pattern. If any of these conditions are present, it's time to repot to a larger container and fresh potting soil. It's also time to break the circular root mass. My preferred method is to knead apart the roots including the bottom, gently tearing apart the matted root formation so new growth will be redirected outward.
Ÿ Lighting is important. Although replicating outdoor lighting conditions is impossible, it's a good idea to provide some supplemental lighting from a south-facing window or an overhead florescent light set to stay on about 12 hours a day. Your goal is not to keep the plant growing — just alive. It will likely go into a dormant or semi-dormant state, so its lighting needs are not as great. But some amount of natural or close-to-natural light will help.
Ÿ Water and fertilizer less. While inside, plants don't require as much water and fertilizer as outdoors, especially those that have gone into semi-dormancy. Slightly damp soil is sufficient. Similarly, fertilization needs are greatly reduced. Moderation is key. To keep a nondormant plant happy while indoors, fertilize at a rate of about a quarter to half of what is suggested for outdoor feeding. Instructions are listed on the label for indoor applications.
Once the risk of frost has passed next spring, you can safely move your plants back outside. Go ahead and water the soil well, but allow them time to acclimate to the outdoors again for about 10 days before resuming a more vigorous fertilization routine.
Ÿ Joe Lamp'l, host of PBS' “Growing a Greener World,” is a Master Gardener and author.