Plan to move tender plants before temperatures dip into the 40’s
There’s nothing like a cold north wind and fast moving front in late October to signal me that I’m out of time to get those tender plants and tropicals off the deck or out of the ground. So, guess what I was motivated to do last night?
Due to the popularity of tropicals and the striking contribution they make to any vista, chances are you too have one or more in your garden, or on your deck or balcony. The good news is you’ll have them for years to come with some good timing and a little care on your part.
The trick is to make sure you protect these cold sensitive plants before they succumb to a killing frost or freezing temperatures. All tropicals can take the heat but most are highly sensitive to cold weather. For the most tender plants, temperatures in the 40’s can do them in. Others can make it through a frost or two but take the sign of this colder weather as their signal for dormancy. In either case, don’t expect them to look very good once Jack Frost has paid a visit.
Some of the most common tropicals include banana, caladium, elephant ear (Colocasia spp.), angel’s trumpet (Brugmansia spp.), hibiscus and one of the most popular structural plants today, New Zeland Flax (Phormium tenax).
Tropicals can be brought into a bright sunny room and grown as houseplants until next spring arrives. However, there are a couple of challenges with this scenario. First, some of these plants have such high light and humidity requirements, unless you have a virtual greenhouse, don’t expect the same lush growth and flowering. Secondly, not many of us have such a room, especially with ample space for the larger specimens.
A more practical solution for many is to store them in a near dormant state in another part of your house or outbuilding. A cool dark place, one that stays above freezing at night and hovers ideally between 40 and 50 degrees during the daytime is ideal. Common choices include unheated basements and crawl spaces, root cellars, garages and potting sheds.
For this storage option, the objective is to keep the part that grows below ground from completely drying out or freezing while allowing the above ground growth to go dormant until next spring. Here are some of the particulars.
Plants that were growing in containers outdoors can be kept in their containers when moved inside to hibernate. Tropicals that have been growing in the ground can be dug up and potted or otherwise stored in a frost free area.
Woody plants like hibiscus and angel’s trumpet should be carefully dug and repotted in a light potting medium. The soil should stay only slightly moist but be sure to check it periodically. Don’t be alarmed if most of the leaves fall off. The goal is to keep these plants alive but not necessarily stimulate new growth.
They can be left unpruned or you can cut back a bit to accommodate space requirements. Because they grow rapidly from new wood in the spring, heavier pruning and any fertilizing should be delayed until that time.
As you remove non-woody tropicals such as cannas, caladium and elephant ears, wait until after cold weather or frost has nipped the foliage and started the process of winter dormancy. There is no need to preserve the old foliage so cut it back to within a few inches.
These plants are easy to dig up and over winter. The source of next year’s growth comes from their bulbs, corms or tubers. For best results, allow enough time to rinse them clean and air dry before storing in a cool dark place as described earlier. Then place them in a container that is well ventilated, such as a crate or basket. Lay the bulbs in peat moss, sawdust or a similar substitute and space them so they are not touching each other. The material should be light enough to allow air circulation and retain just enough moisture to prevent the bulbs from completely drying out.
A month or two before next spring approaches, you can repot the bulbs for an early start to your spring garden, or wait until after the last frost and plant them directly in the ground again. Either way, over wintering tropicals is an easy, effective and economical way to keep your plants coming back better than ever year after year.
About Joe Lamp'l
Joe Lamp'l is the Host and Executive Producer of the award winning PBS television series Growing A Greener World. Off camera, Joe dedicates his time to promoting sustainability through his popular books, blog, podcast series, and nationally syndicated newspaper columns. Follow Joe on Twitter
i live in south mississippi and have planted, in the ground, 2 hibiscus. i will not be digging them up for winter months. how can they be protected?
Tracy, If you don’t want to dig up your plants for the winter, there is always a chance that they will not come back if you live in Zone 7 (hardiness). Problems occur when there are extreme fluctuations in temperatures. With this in mind, I would recommend not cutting back your hibiscus until early spring (right about now) before new growth begins. Make sure you apply a good two inch layer of mulch in the fall and keep track of the weather. Cover your plants with a blanket or burlap if extreme cold temperatures are forecasted. Make sure to uncover them during the day, once the sun comes up. Make sure too that they don’t dry out, they don’t need to be sitting in soggy soils, but adequate moisture is important. I hope these suggestions are useful. Good luck!
I live in zone three and my tropicals include a large sago pine, a 5 foot Majesty Palm and a 7 foot elephant ears, and several begonias, ivys and spider plants, I have usually wintered them in my heated home for the winter and treated them as house plants. I have many large windows but they would normally go dormant until I start to water them more and feed them in early March with the onset of longer days and brighter sunshine. I am going to try something radically different this year and I am going to create a mini green room in my basement bedroom and use one of my grow lights to use as a consistent source of light. I will be able to better control the humidity and I am hoping that rather than go dormant they will continue to grow as they do in the natural habitat. Any feedback would be appreciated and anyone else who does this, your experience would help!
I love you are willing to experiment. And, I think you’re plan might work. But is there any natural light in this basement bedroom? I think that’s still important, even if it’s indirect. Typical consumer grow lights, unless they are really strong, don’t have the power to simulate outdoor light. I have colleagues that do similar things with success but when combined with locating plants by a window. Please keep us posted on how this turns out.
Can I actually cover my potted tropical plants with clear plastic with holes perhaps? I usually put my potted tropical plants in the basement but because I do not have enough space I am planning to place them instead in a crawl space below a porch and cover it with mulch as well.
I would not suggest this Markus. The same plastic that will protect your plants in the winter, will also cook your plants when the sun is overhead and the heat builds up underneath. You just can’t get consistent protection by leaving them outside under plastic like this.
This plant is Ensete maurelii ?
thanks
Great post, and I like the emphasis on just keeping the plants alive. A lot of people tend to overwater the plants, or stimulate growth that only weakens the plant further when it doesn’t get the sun it needs. Thanks for calling attention to the subject of overwintering tropicals! 🙂
Right Steve and thanks. Overwatering is the subject of many a plant’s early demise. How awesome would it be if we could all back off the watering a bit, and save a lot of such a precious resource!
Thanks for your comment.
i live in zone 7 i believe,newnan ga.. my question is ,can i plant and keep in ground my plumeria. i have elephant ears, angel’s trumpet,banana trees,and they always return every year. thought of placing lava rocks around base to help keep warm. when in grounds grows great, not so good in planter. help please
Tina, It sounds like you have had good luck with tropicals so I would go ahead and try leaving the plumeria in the ground and protect it with mulch. Not sure about the lava rocks. I would not cut back any growth until early spring right before new growth begins. The one thing that is hard to predict is the sudden drop in temperatures that happens. Cover your plants with plastic and or a sheet if you know about frigid weather in advance. Be sure to uncover them the next day once the sun comes out. Happy gardening.