Winters can be cold, dark, and depressing. If you are lucky enough to have a sunroom, cultivating a beautiful set of plants through the winter is a great idea. Sunrooms can get quite cold in the winter though. This guide will show you the best plants for your cold sunroom. We also cover how to keep your sunroom warm in the winter so those plants thrive.
A successful winter sunroom uses the right plants and the right techniques. First, determine how cold your sunroom will get at night. Second, pick the best plants for those temperature ranges. Houseplants (zz, pothos, etc) and garden staples (kale, oregano) can all do well. Third, keep the sunroom warm by sealing leaks, insulating, or heating it.
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Best winter sunroom plants
Picking the best plants for your 4-season sunroom is an essential choice. Different regions will experience dramatically different temperatures at night. In southern Florida, you could grow absolutely anything in your sunroom in the winter. But in Maine, you would need to be far more careful about picking strong, hardy plants.
Luckily a lot of our favorite houseplant species can do well down to temperatures around 40 degrees Fahrenheit. If you expect the temperature to drop below that, use one of our strategies in the second half of this article to keep things warmer.
Here are a few of the (many) plants that can bring some greenery to your cold winters.
A houseplant staple, the ZZ Plant can survive as long as temperatures do not drop below 40F. These plants are common and beautiful. They make an easy addition to your sunroom spread.
This species can tolerate low light, dry weather, and cold temperatures. This makes it ideal for a winter sunroom. It also has beautiful flowers!
The venerable spider plant can survive down to 35 degrees. It won’t grow much under 65 degrees though. These plants are so productive and cheap they can easily fill out your sunroom arrangement.
Pothos is a classic. Its beautiful vines filled with dark green leaves lend a tropical feel to any space. Trellis this plant up the walls of your sunroom. Hardy down to 40F, pothos delivers.
Many succulent species are from the desert where the daytime heat is paired with freezing nighttime temperatures. Each species differs, but Haworthia, Jade, and Gasteria can all do well with low temperatures and low light.
Bring some height in with the Ponytail Palm. Beautiful and tropical, the Ponytail Palm can survive as long as the temperature does not go under 40F. Its low water needs also help it tolerate the dry winter air.
Ornamental varieties of Kale and Chard grow well even outside during mild winters. Start them off in the late summer in pots outside, then bring them into your sunroom in the winter. They can take near-freezing temperatures.
Sage, Thyme, Oregano
These classic herbs are low-growing perennials that often survive even under the snow. They do well in dry and cold conditions. Use them as a groundcover in pots or planters.
Keeping plants warm in a winter sunroom
Even the hardiest plants can die if the temperature gets too cold. Use these easy strategies to keep your sunroom at a comfortable temperature even in the depths of winter.
1. Open the door
The first item on our list is such a simple trick. Just open the door connecting the sunroom to your house during the coldest nights that you are worried about your plants. This will let the heat from your house flow into the sunroom keeping away the worst of the winter chill.
This might raise your heating bill, but especially for very cold nights, this strategy will keep things tolerable for all of your plants.
Putting a fan in the door will force even more warm air in.
2. Seal any leaks
Many sunrooms are an older design that may have seen some wear and tear. It is quite easy for gaps to develop along the edges of windows and doors and the panels that make the sunroom.
These drafty leaks can make the temperature in your sunroom plummet. Sealing these should be one of your first steps.
You can use weatherstripping (basically insulating tape) to seal along the edges of your windows and doors.
If you have larger gaps, use a clear caulk to patch them up.
If your sunroom has an external door, place blankets or a rug along the bottom to make sure that a draft isn’t blowing in under it.
3. Insulate with thick curtains
The windows are the largest part of any sunroom. Unfortunately, they can often be thin and lose a ton of heat.
Double-pane or insulated windows can help, but you can also easily decrease how much heat you lose through your windows. We recommend getting some thick drapes or curtains to cover the windows at night.
Make sure to get curtains that are specifically marketed as “insulating”. This will make sure they keep in the maximum amount of heat.
4. Circulate warm air with a ceiling fan
If you have a ceiling fan in your sunroom turn it on at night. Since hot air rises, your plants might be left in the cold while all of the heat stays up near the ceiling.
Activating your ceiling fan on even a low setting will keep things circulating and should make your plants much warmer.
If you don’t have a ceiling fan, you could easily place a portable fan on the ground pointed upwards to get the same effect.
5. Use an electric heater
Running a cheap electric heater can skyrocket the nighttime temperatures in the sunroom.
Be careful though, some space-heaters can easily cause fires. Make sure to keep it away from anything flammable if it falls over. Also, get a heater that does not have an exposed heating element. Anything glowing red hot could easily start a fire.
Finally, keep pets out of the room when the heater is on as they could easily knock it over and cause a massive problem.
6. Let passive solar heating keep things warm
Sunshine keeps your sunroom warm in the daytime. If you are clever, you can trap that energy and use it to keep things warm at night.
The key is to use materials that easily absorb and store the head around your plants. Black and dark colors absorb the most heat. Heavy materials like bricks, stone, and water are best at storing them.
Dark tiles and bricks placed in and around your pots can help absorb and release sunshine.
Spray paint milk jugs black and fill them with water. Place them near your plants and they should release some heat during the night.
7. Position them right
The area near the windows will be the coldest. If possible, move your plants towards the center of the room or whichever side is closest to your home. This will help avoid the coldest temperatures.
Use a thermometer gun to check the temperature in different parts of the sunroom at night. Then you can place your plants in the warmest sections.