Overwintering Tender Plants: Tips for Keeping Your Tropicals Cozy
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As temperatures drop this time of year, my phone buzzes nonstop with texts and calls from friends wondering how to protect their beloved tropicals—like hibiscus, citrus trees, and aeoniums—from the chill of winter. It all boils down to one word: overwintering.
Overwintering is about giving your plants the care and protection they need to survive the colder months. Whether that means bringing them into a sunny indoor spot, tucking them into shelter, or wrapping them snugly with lights or covers to fend off frost, biting winds, or sudden cold snaps, a little preparation can go a long way.
Understanding Overwintering
The goal is simple: shield your plants from extreme cold, harsh winds and heavy rain, while managing the challenges of low light and shorter days to keep them healthy and happy until spring. Tender plants, native to warmer climates, are especially vulnerable to freezing temperatures, which can cause severe damage or even kill them.
In winter, lower light levels slow plant growth resulting in lesser needs for water. Overwatering can lead to soggy soil and root rot. In the Pacific Northwest, where wet winters pose as much of a threat as the cold, finding the right balance between protection and light is key.
Know Your Plants
Each plant has different needs. Some like aeoniums and Meyer lemon trees can handle cooler temperatures and survive a slight, temporary freeze. Others, like begonias and asparagus ferns, can't tolerate freezing temperatures at all. Understanding your plants needs will help you choose the best overwintering strategy.
When to Bring Plants In
If you’re wondering about timing, watch for two things: frost threats and overnight temperatures consistently below 45°F. I like to leave my plants outside as long as possible—typically late October to early November—so they naturally slow their growth. This way, they’re ready for the shift indoors before the first big frost hits. In Seattle, frost was predicted two weeks ago (still waiting on it!), but when overnight temps consistently dipped into the mid-40s, I knew it was time. Keeping an eye on the weather forecast ensures you’re not caught off guard. Once temps hit 32°F, frost can wreak havoc, damaging or even killing tender plants left outdoors.
Inspect Plants Before Bringing Them In
Before moving any plants indoors, huddling them together, or covering them up, give them a good once-over. Check under leaves and along stems for hitchhiking insects or fungal diseases.
For instance, I recently spotted scale on my Thai lime tree so I’m treating it before grouping it with other plants or bringing it inside. A quick rinse or wiping down pots can also help prevent problems from spreading.
Choose your Overwintering Strategy
Depending on your plants and space, you have three main options:
Bring Them Indoors
For plants that thrive in warm conditions, indoors is the best option.
- Gradual Transition: To minimize shock, gradually transition your plants indoors by increasing their time inside over a few days.
- Find the Right Spot: Choose a location with plenty of light and consistent temperatures. A sunny south- or west-facing window is usually best. Keep plants away from heat vents where dry, warm air can stress them, making them more vulnerable to pests or diseases.
- Temperature Tip: Most tropical plants do best with daytime temperatures of 65-75°F and slightly cooler nights.
Store Them Dormant
Some tropicals, like cannas, Colocasia, and bananas, can be overwintered in dormancy.
- How-To: Cut the foliage back to a few inches. Depending on space, either dig up the tubers or bulbs and brush of excess soil or leave them potted.
- Storage: Keep them in a cool, dark spot like a basement or garage. Wrap bulbs or tubers in newspaper, or towels, or store them in a box with peat moss to wick away excess moisture but keep root system slightly damp. If left potted, or wrapped check monthly for signs of too much moisture, mold or shriveling. and water sparingly if needed.
Protect them Outside
Unwieldly plants like large bananas or those a bit hardier like certain citrus trees can often stay outdoors with extra protection.
- Insulate Pots: Wrap containers with bubble wrap or burlap to protect roots from freezing when temperatures drop to dangerous zones.
- Cover Plants: Use frost cloths or breathable fabric to shield foliage from frost and wind when conditions arise where they can do damage. Remove coverings as soon as the risk passes to allow light and airflow.
My Overwintering Cheat Sheet
Here's how I’m caring for my tropical and tender perennials this winter:
- Aeonium spp.- These need a sheltered spot above freezing with minimal watering. In the PNW, where our winters are wet, they’re better off undercover or indoors.
- Begonia rex-cultormum -This makes for a gorgeous winter houseplant placed in a bright spot with indirect light away from vents to avoid dry air. I'll water sparingly and let it enjoy the cozy indoor temperatures of 60-70°F.
- Canna spp.– After removing the leaves, and cutting stalks back to 4-6 inches, I'll wrap the root ball in a towel, and store it in a heavy-duty contractors bag in my shed, which stays above 40°F. The towel helps absorb excess moisture, keeping the root ball damp but not soggy.
- Ensete ventricosum (Banana) – Like cannas, I'll remove the leaves and cut it back before moving it into my shed. Alternatively, it could be left intact and be placed in a bright window or under a grow light for the winter.
- Citrus x Meyeri (Meyer Lemon Tree) –It stays outside under the eaves until nighttime temperatures dip below 35°F. Indoors, it will enjoy a sunny east-facing window and occasional misting to maintain humidity. I’ll fertilize it in early March, using a dosage specific to potted plants.
- Citrus hystrix (Thai Lime Tree) – After treating it for scale, it will settle into a sunny window with regular misting and consistent watering. I’ll fertilize it in early March, using a dosage specific to potted plants.
- Colocasia esculenta 'Diamond Head' (Taro)– If space allows, I’ll keep it potted in my shed, cutting it back to the ground and watering minimally. Otherwise, its dormant corm will rest in a paper bag in the garage.
- Draceana marginata 'Tricolor'(Dragon Tree)– A lovely houseplant in the winter, it thrives with indirect light and soil that's allowed to dry out between waterings.
- Hibiscus 'Jazzy Jewel Amber’ – Mine goes dormant in the garage, where it gets minimal light and stays just above freezing. Watering is sparse—just enough to keep it alive.
Looking Ahead to Spring
Overwintering tender plants may take a bit of effort, but it’s so rewarding to see your prized possessions thrive year after year. Once the frosts are behind us, they'll need a little extra care to ease back into outdoor life. Give them a bit of time to readjust by gradually introducing them to sunlight over a few weeks and before you know it, they'll be bouncing back beautifully.
In the meantime, here’s to embracing the slower season ahead—savoring cozy days indoors while your tender plants rest safely, tucked away waiting for warmer days to return.
Happy container gardening!
