Now that many gardeners in frostier USDA zones have learned about and acquired cold hardy tropical plants, there are palm trees in Indiana, orange plants in Ontario and magnolias in Utah. Whether these cultivars were bred from hardy Asian varieties or are grafts made on freeze hardy root stock, cold hardy tropical plants aren't completely safe from some types of freezing or storm damage. Here are some ways to help your tropical garden make it through a tough winter:
KNOW THY GARDEN
Whenever you add a tropical plant to your collection, keep plant tags in a special folder or envelope. Be sure you know exactly how cold a plant can get before it needs protection.
Also know your hardiness zone, but be aware that dips in elevation and other features can make a tropical garden warmer or colder than your designated growing zone might suggest.
Don't necessarily freak out if a particular plant is out of its league - winter wise - due to a sudden unusual cold snap. For example, the plant tag may say the variety is hardy to -5°F, but the weatherman says the temperature will drop down to -15°F. Your plant may still survive if you take the steps described below.
Likewise, a very cold hardy plant can be destroyed by a sudden frigid period, so take precautions for plants if they have not been gradually acclimated to freezing temperatures.
USE NO BLADE, ALLOW NO FOOD BUT DO GIVE WATER
Heavy, sustained winds can dry out even the hardiest plant, so wrap vulnerable trunks and foliage if cold gusts are in the forecast. You can also help your plants retain moisture by giving them a nice soak before freezing temperatures arrive.
Don't feed or prune tropical plants before winter. Feeding plants or trimming branches will promote tender new growth that won't be able to stand up to fierce weather.
CHOOSE SUITABLE CLOAKS AND COVERS
Many materials can be used to give plants some shelter from snow, ice and wind. Bubble wrap and heat reflective sheeting are good choices for smaller plants. Inverted Styrofoam coolers and cardboard boxes also work when weighted down.
Using stakes to hold up sheets and comforters is a strategy for larger shrubs and plants. Taller palms and other plants may be impossible to completely cloak, but you can wrap the trunks and perhaps salvage the tree by cutting back freeze damage to the living part later.
Mulches won't protect anything above what they are covering, but a heavy layer of leaves, straw or other mulch can protect ground covers and dormant ferns. Mulch isn't worthless over taller plants. It can help the roots stay warm and moist so that even if the plant dies back to the ground, its root system will be healthy enough to send new shoots come warm weather.
No matter what you do, you may lose some of your plants if there is an unusual cold snap. Don't despair. Instead, make note of how various plants performed throughout the cold season so that you learn which tropical plants and which winter strategies will work in your growing zone. Hire professional landscapers, such as SWF Construction, LLC, for extra help.