Brian Minter: Tropicals for outdoor spaces

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During the COVID-19 pandemic, as the trend of making our homes and living spaces more appealing continues, we in the gardening industry are seeing a huge interest in creating more tropical environments, especially among folks who have outdoor pools, hot tubs and sunny patios. It’s a great idea, and one we can all share, but there are a few considerations to keep in mind.

Timing is one of the most important. Until our nighttime temperatures reach a consistent 10 C, please hold off on any tropicals. Warm, sunny days can be deceiving. If night temperatures dip down close to freezing, or just slightly above, the beautiful leaves of show-off specimens can be seriously damaged. It’s possible that many folks have already burnt their prized tropicals by putting them directly out in the sun during the day.

Even when a tropical palm or banana is purchased from a store, it needs to be properly acclimatized to local outside conditions before being set out. This means putting it in a protected outdoor area, sheltered from the sun and wind, for a week to 10 days, so it can adjust to the new environment. Once this adjustment period is complete, the plant will adapt much more easily to the often changing outside elements.

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The so-called hardy, green-leafed banana, particularly Musa basjoo, is the most popular and, perhaps, easiest care tropical. Originating from the most northerly islands of Japan, these bananas, with their four- to five-foot-long green leaves, are stunning. It’s best to locate them away from very breezy locations where strong winds can break or damage the beautiful foliage.

In areas rated Zone 6 or higher, they can even be planted permanently in the ground to be enjoyed most of the winter. During cold spells, however, they will need to be protected with a proper insulating wrap or cut down and their roots mulched, ready for new shoots to grow in late spring. When planted in larger containers, they can be enjoyed outside well into fall, but will need to be moved into a protected area during a cold winter storm.

The spectacular, red-leafed banana Ensete Maurelii is a far more tender variety that should go outside only in mid- to late May and must hibernate inside once the temperature starts cooling down in mid-October. For most people, finding adequate indoor space will be an issue.

Palms have become the go-to outdoor tropical, and they really do make a statement. One of the hardiest, most readily available varieties is the windmill palm (Trachycarpus fortunei). In their native habitats of northern India, Nepal, Australia and Southern China, they can tolerate -12 to -15 C, but younger plants in home gardens will need protection once the temperature drops to -5 or -8 C, especially if they’re in containers. Rated a Zone 7b plant, it’s well-suited to southern Vancouver Island, the Gulf Islands, southwestern B.C. and Greater Vancouver. In colder parts of the Lower Mainland, it’s best to leave them in their containers for moving to a protected location during cold winters. If left planted in the ground, they will need strategic wrapping for winter protection.

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Although not as plentiful or hardy, many other palms can add tropical beauty to outdoor living areas. Once properly hardened off to outdoor conditions, the range of varieties expands considerably: the Chinese fan palm (Livistona chinensis); the lady palm (Rhapis excelsa); an Afghanistan native, the mazari palm (Nannorrhops ritchiana); the saw palmetto (Serenoa repens); the sago palm (Cycas revoluta); and the California fan palm (Washingtonia filifera) are all candidates for summering outdoors in Zones 6 and 7 locales. In Zone 8, you might be able to enjoy them in winter as well if they have some protection during cold spells.

Eucalyptus, a semi-hardy tropical tree, is becoming very popular for its cut foliage. In Australia alone, there are over 500 different varieties. They are generally hardy in Zone 8 and higher. With some winter protection, they can be grown in Zone 7, and over time, they should develop into a reasonably resilient tree. Most varieties are very fast-growing and, in my experience, when started from seed, you can expect a two-metre tree by fall. Eucalyptus gunnii (cider gum), with its beautiful, fragrant blue foliage, is one of the hardiest. They do great when grown in containers, and if planted in well-draining, protected spots with good winter protection, they will surprise you with their resilience.

I love the fact that each year they can be hard-pruned into the old wood and will still send out lots of fresh new foliage within a few weeks.

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We are also seeing a crazy demand for citrus plants. With their intensely perfumed flowers, it’s not hard to see why they’re so popular for patios. They’re far more cool-hardy than folks realize, and once acclimatized to outdoor sunny locations, they will tolerate temperatures just above freezing. They don’t perform well indoors in most household conditions. If you can protect them from frost, they’re better left in a cool, well-lighted greenhouse type environment over winter. At this time of year, once hardened off, they can certainly venture out onto your patio to be enjoyed all summer. You can definitely expect fruit from any flowers, as long as they have enough ripening time over summer and fall. Citrus plants are lots of fun if you can find just the right overwintering location.

I makes me sad to see bay trees (Laurus nobilis) growing in European gardens, while we see so few here in the Lower Mainland. Years ago, I planted one in a solid Zone 6 spot in the Fraser Valley, out of our notorious winter outflow winds. It now measures three-metres across and five-metres tall. The fragrance alone makes it a great plant, and its beautiful leaves are so useful for flavouring our culinary endeavours.

Again, it’s finding that protected, hot, well-draining location for the first few years and providing great winter protection that will make all the difference. Over time, they will become far more cold-tolerant.

It’s a bit of a show-off thing to have a tropical look on your patio. How successfully it can be done will depend on where you live, what your microclimate is like and your ability to ensure just the right winter protection and location. As we edge closer to that 10 C nighttime temperature, you just might consider upping your game with some of these very special tropicals.