Overwintering Houseplants
In climates like central North Carolina (Zone 7b), a shady porch or nice spot beneath a tree can be a perfect place to put your houseplants for the summer. They will get more light than by a window and greater air space with room to grow. The question is what to do with theses tropical plants when autumn comes and the landscape begins to go dormant.
Cuttings of the Coleus can easily be rooted and kept indoors to grow new large plants in the spring.
Obviously you bring them inside your home or greenhouse but there are key practices to keep in mind in the process.
Make sure you don’t wait to long!
This is important because you don’t want to give your plant a major shock when it’s halfway through November and we have already experienced temperatures in the 30s.
Temperature matching can be important.
Bringing a plant from 40F to 74F immediately on a late autumn night is not going to feel right for the plant and could deliver negative stress. Bringing a plant inside during the day when the temperatures are in the 60s will be a much less drastic transition and in many cases you can continue some growth.
NC Winters “Sminters”
As school kids growing up in North Carolina we dreamed of more snow. This is especially true for residents of Raleigh and Eastern NC. Our winters are not that drastic in Zone 7b. You can grow these seemingly tropical houseplants in the ground and they should generally return every spring:
Fatsia japonica
Flytraps and Native Pitcher Plants
Some selections of Colocasia and Alocasia
Aspidistra (most varieties)
Sabel minor and Trachycarpus
Farfugium gigantium
Hardy Maidenhair Ferns
This variegated Aspidistra elatior could probably survive a winter in the ground, but will likely appreciate a warm setting indoors.
Just remember some will not stay evergreen and go dormant. If you can cut off their frosted dead foliage and put a nice pile of mulch over them, remembering to remove the mulch in the early spring, you should be good to go. Be careful if you have these plants in pots because they lose a lot of hardiness above ground.
Check for pests!
You don’t know what your plant might have picked up on the wind outdoors all summer. It is important to spray plants with Neem Oil thoroughly to get a first deterrent down for spider mites. A drench with imidacloprid or wiping down thoroughly with alcohol is your only defense from scales. Remember pests from your outdoor plants can move to your houseplants, so be on alert during winter.
Armored Scale and an ant drinking the plant sugars from the damages on a Meyer Lemon Tree. You don’t want to bring this in your home as it could spread to other plants!
Spider Mite damage on a Wisteria, while this plant is deciduous and hardy, many of your tropical plants will show similar symptoms if they are infected with mites.
Cheap and easy pest control products.
Light and more of it.
Very energy efficient LED T8’s offer more growing space and barely raise your power bill.
Your plants that just came in for winter are going to do best with as much light you can provide them during the winter. If you don’t have enough space from your window light, you will need to set up grow lights. The best and most economical option is to buy standard shop light ballasts and LED fluorescent replacement bulbs, 5000K, and a timer. Links to some at Lowe’s are here:
Of course the bulbs don’t run very hot and they diffuse light fairly well. The closer you can get them to your plants the better the rate of photosynthesis will be.
Even a lamp with a daylight LED Bulb or Compact Florescent can be effective for growing when positioned appropriately.
Succulents are an exception.
Succulents are not like most of your tropical houseplants that must come inside all winter. Succulents are home to cool, dry, sunny climates that don’t freeze. As long as they safely stay away from temperatures under 35F the succulents will LOVE growing outdoors in winter and express some of their most beautiful colors! Just remember to protect them from rain and water sparingly. A good tip that makes it easy to bring them in when cold temperatures are threatening is to put your succulents into crates for the winter.
With so many warmer days in the winter here, These will only need to come in when the temperatures are going to drop beneath freezing.
Fertilize a lot less!
Cut down on your fertilizers a lot in the winter time. With less light that comes with the shorter days and generally lower temperatures and drier air your plants won’t be actively growing as much.
I wish you the best of luck bringing your plants inside for the winter. Just remember these few simple principles and you’ll have great success!