Gardening in the Greater Vancouver area of British Columbia is such a pleasure as there is a great deal of diversity of plant materials which grow well in our climate. Not only can we grow a broad spectrum of temperate plants but we can also experience the thrill of growing many varieties of heat-loving plants in our gardens and on our decks.
But what do we do at this time of year when days are shorter and temperatures dip toward freezing at night? It would be nice to be able to move all the heat-loving plants into a heated greenhouse so as to have them readily available for the following spring and summer. Lacking the heated greenhouse one might find that tossing them in the compost pile would be the alternative. Most of us plant lovers are too tender hearted and frugal to go this route.
Outlined below are some tips that you might use to provide some winter protection to the tender plants you have grown thus saving the plants themselves instead of absorbing the cost of replacing them again next year. Most heat-loving plants can be overwintered using one or more of the following methods.
1.Keep your plants in the active growth mode by supplying them with a warm and bright environment. This can be achieved by using a heated greenhouse or placing them in a sunny window location in your home during the cold winter months. A few plants that respond well to this treatment are:
Elephant Ears Tropical Hibiscus
Remember to turn the pots occasionally and water when the soil is dry
2. Provide a bright but cool area for plants that can handle light frost. This might be achieved by moving the plants into the basement or into an insulated garage. In either case light may have to be provided by a window or by artificial lighting. Plants will need to be turned occasionally and watered when the soil is dry. Plants that respond to this treatment are:
Flowering Maple (Abutilon)
New Zealand Flax (Phormium)
3. Provide a cool and dark location for many tropical and semi-tropical plants. This is the ideal condition for plants that go dormant during the winter months. This can be provided by placing the plants in a crawl space, garage or insulated outbuilding where they will not be subject to freezing. This is the preferred method of overwintering many bulbs, corms and tubers such as agapanthus, begonias, caladium, calla, canna, dahlia, ginger, and sweet potato vine. This is often achieved by packing the bulbs/corms and tubers in shavings or peat moss with minimal moisture. Many non-bulbus plants can also be stored in a cool and dark location such as:
Many tropical and semi-tropical plants grow to sizes that make it difficult or impossible to over winter the whole plant. Where this might be a problem it is a typical practice to take cuttings and root the cuttings so that they are available for planting in late winter or early spring. They can then be introduced to your garden when frost danger is past, probably in late April or early May.
Some tender plants that have achieved large size may be provided winter protection where they are growing by covering the base with their own leaves as in Gunnera. Larger palms and large but tender banana plants may have to be wrapped with bubble wrap or other protective materials to prevent being killed by cold winter weather.
No matter what methods you use to over winter your plants you should expect some losses but it is real joy to be successful. Good luck and happy gardening.
Del L Knowlton