Overwintering Tropical Plants

You can overwinter many tropical plants by just bringing them inside for the winter.  I have a six-year old hibiscus that resides, and blooms, in my living room until later April.  The only problems I have had is that the plants, unless given supplemental light, may look ragged and tired by the end of winter and we get fungus gnats, tiny and annoying, but not harmful, bugs.  I recently began using a BT (Bacillus thuringiensis,  http://en.wikipedia.org/wiki/Bacillus_thuringiensis) product from Gardens Alive  (KnockOut granules
http://www.gardensalive.com/product.asp?pn=3440  ) that is organic and harmless to all but the gnats and it seems to be effective.
Overwintering an aquatic (pond) tropical plant is a different matter. I have been overwintering an umbrella palm (photo above) for several years.  Umbrella palms are easy to root, just cut off the long stem and place the "umbrella" in water, but these take a few years to get to a decent size, hence I bring it in from the pond. I have also overwintered floating water hyacinth with success.  These plants are overwintered in an out-of-the- way place, my attic, as they are not very attractive and can get a little smelly (change the water if this happens).  They need supplemental light, under hanging florescent tube lights.They need a sturdy container that does not leak and holds a sufficient amount of water to keep the plant alive.  Here I am using a crisper drawer from a long-defunct fridge (Reuse, Reduce, Recycle!).  It is sturdy and clear and I can check the water easily for bugs.  I do not bring in pond water- this guarantees bugs, and perhaps hatching mosquitoes, in your house! I use tap water, with the proper amount of a de-chlorinator sold for ponds, or cholrine-filtered water.
So, plan to bring those tropical plants inside in the future (BTW, I brought this umbrella palm indoors on 11/26- the pond retains heat and it was still unfazed by the cold!)
Happy gardening!

More on bananas and other tropicals

I am starting to move my tropical plants to my front porch, preparing to bring them inside for the winter (see my pod cast, VirginiaOrganicGardener, on itunes or at http://virginiaorganicgardener.podbean.com/ this week and next for tips on dealing with unwanted critters coming in on these plants!) My banana plant, despite the cold, has put out another flower that I will get to enjoy indoors for the next few months..and maybe sketch too. This is one of the joys of many tropicals, like citrus and hibiscus: getting indoor blooms in the dead of winter. My set up to keep them going is simple: they are placed on a tarp, under long florescent fixtures in my insulated, and occasionally heated, attic.
Happy gardening!

Overwintered potted plants

I overwinter a lot of plants- some in my attic under supplemental florescent light, some on a kitchen windowsill and others in my garage. These garage plants are a little sturdier than the ones I over winter inside, plus they usually cannot stand the dry conditions inside a house (I once read that to provide indoor air moisture equal to outdoors, you would have to mist inside plants a hundred times per day). Another reason to overwinter in my garage is when the plant is dormant and needs just a little extra cold-weather TLC. Potted plants are especially vulnerable to the freeze-thaw cycle (which also cracks ceramic or clay pots). The roots of potted plants are essentially above the ground and can freeze badly and dry out easily if left outdoors all winter. Going into an unheated garage or shed can provide enough added protection to allow the plant to survive.

If you overwinter pots this way you may encounter the same problem I have- the potted plant seems to break dormancy early in these sheltered conditions. This is a problem- these plants cannot adequately photosynthesize in the dark conditions in my garage nor will they come into proper bloom. I don't want to set them outside without protection: after all, they were protected from the harsh, outdoor conditions all winter. So, this is what I do- I mass the plants in pots near the house and cover them with pine straw (I tuck pine straw under, between, behind and over the top of the pots-see photo above). The house provides a wind break and some heat pools. This protects the plants and pots, allows rain and some warmth from the sun, and it conditions the plants to the outdoors. If the plant is truly early, this may slow its growth down just enough. Some people put potted plants in a cold frame- my cold frame is too small for the 15-20 large pots I have (even if it hadn't gotten loose from its rope and stake mooring in a windstorm and flew up 10 feet and broke apart!) You can also trench your potted plants- that is, put them in a trench and cover with straw, hay or leaves for a month or so, until it warms up- perch them on brick for drainage. In a month, your plants will be truly ready for spring...as will we all!

Happy gardening!

Overwintering

I have used the word "overwintering" a few times in this blog- then a friend asked me what I meant by it. Overwintering is taking a plant that is usually potted, into the indoors or into a sheltered location for the duration of the winter. Overwintering can allow a plant that is not normally hardy to your region to survive until the next growing season. Sometime it is as simple as bringing a plant indoors and putting it next to a sunny window. I do this for hibiscus and a curry leaf tree. Both suffer some leaf loss from the lower light and drier conditions, but later rebound- and the hibiscus sometimes rewards me with an indoor bloom or two! Some plants simply need some minimal shelter, like an unheated garage, and this is where I put my potted exotic bulbs, passionflowers and bonsai plants. I water them sparingly, as they are dormant during this time.

Some plants need a bit more care. Last year I overwintered a Meyer lemon in a sunny window. Though it survived, it looked pretty ratty by about this time. This year, I put my Meyer lemon, Kaffir lime (top photo), lemongrass and a few other outdoor plants in my heated (but cooler than the rest of the house) attic under florescent lights. The plants look great, and the Meyer lemon is rewarding me with fragrant blossoms! (see photo below).


I am also overwintering some large ornamental bananas (photo below), though I am not completely certain they need this level of care. I have read about people in this region storing them in an unheated garage, waiting for them to send out a daughter plant in the spring.


You need to watch for light levels, but also for over-or under-watering and pests. Plants do not put out as much growth in the winter, so could easily get root rot from too much water. When you first bring the plants indoors, you might also bring in some hitch hiking aphids, white flies or scale bugs (among others), so some sources recommend dousing the plant and the soil in insecticidal soap (no chemical fertilizers, you do not what them in your home, as they are not meant for indoor use) and isolating the plants from other houseplants for a few weeks.

After the last frost, my plants will go back outside. I might try to acclimate them to outdoor conditions for a week before the last frost, and will first put them out on a shaded and protected porch for a few hours, increasing the length each day. This is not possible with my HUGE and HEAVY banana plants...I can only ask my son and husband to drag them out of the attic to their final destination in one go! (DO NOT heavily water a large potted plant just prior to moving it- let it dry out a bit, or it will be a messy job to move!)
[Later note: my husband, upon viewing these plants in our attic asked if I had posted photos of them on this blog, so that I could get the "proper insane, obsessed gardener street cred." ! ]

Visit my garden pod cast, VirginiaOrganicGardener by clicking on the pod bean button on the top left of this page! Happy gardening!