It’s Time to Move These Plants Indoors for the Winter.
There are certain plants that will not survive winter outdoors. Sometimes people buy plants that they intend to keep indoors all winter, like my indoor lemon, which goes off in the summer and comes back on in the winter. (Experienced gardeners use the summer to give their houseplants some air by moving them outside for a few months and then bringing them back inside.) There are all the potted annuals you buy every year for the outdoors; the only thing that kills them is cold weather, so these pots can be brought home in late summer. Finally, there are plants that you plant in the ground that really should be stored for the winter, such as dahlias or begonias.
Regardless of why you’re bringing plants inside, it’s just about moving day.
When to move plants inside
In the spring, we plant when night temperatures reach 60 degrees. When temperatures drop to 45 degrees in the fall, it’s time to move your plants indoors. However, if there is a frost warning, this exceeds the constant temperature and you should initiate an emergency evacuation.
Which plants to move
Many people have plants that they move indoors and outdoors seasonally because their growing area cannot support such plants. (Tropical and citrus plants are good examples.) But you can add annuals like tomatoes and peppers to the mix. Last year I talked about how to prune these annuals to put them in pots for the winter. It would be wise to try bringing in any annual you keep in a container, including herbs such as basil and parsley. Of course, you can try transplanting annual plants from the ground into a pot, such as petunias and marigolds. In especially cold places, gardeners dig up bulbs of dahlias, begonias, cannas, elephant ears, gladioli and calla lilies, clean them of dust and store them indoors for the winter. If you live somewhere that doesn’t usually get hard frosts in the winter, you may want to risk leaving the bulbs in place.
Keep bugs out of your home
There’s a good chance your plants have made some friends this summer, and those friends will be very happy to hitchhike to your living room on a leaf and then take all your houseplants. To prevent this, you need to inspect each of your plants before they go inside and give them a good dip . Dip the plant upside down in a bath of water with neem oil and Castile soap until all the leaves are covered; then place the entire plant—pot and all—in the same bath until no more bubbles appear. This will help control a limited number of pests, but if you still see anything on those leaves, consider calling your local nursery for a surface treatment.
When you need a bigger pot
All that vitamin D from outside can have a transformative effect on the plant. Your pet may need a larger potty to stretch his legs, and now is the time to do so. Remove the plant from the pot, untangle and loosen the roots, and inspect them for health. Trim diseased and/or moldy roots and look for pests. Before replanting, dip into fresh soil as described above. You can also divide the plants now or trim the leaves.
What your plants need inside
Different plants have different winter needs. For plants that you intend to continue to grow and bloom, you need light and warmth (but not too much or direct heat), as well as food and water. This group can include any flowering annuals and indoor plants.
For plants like citrus, you need light and warmth, but in the winter you will slow down the plant’s growth so it will go into a dormant period. You will begin to reduce the amount of water and fertilizer to encourage it to slow down.
Your tomato and pepper plants will go into a period of complete dormancy, which means they only need a few hours of ambient light per day. A basement is ideal and you will give them enough water and light to keep them alive but not much more, slowly waking them up in the spring.
Your light bulbs need darkness. Let them dry and then wrap them in newspaper and place them in the basement or garage where they will be safe but at a temperature of 60 degrees Fahrenheit or below.