Going Tropical, Southern Great Lakes Style

Going Tropical, Southern Great Lakes Style

I know, I know! No matter where someone gardens, it's always easy to get a case of the "zone envies". This is fairly typical and usually hits most gardeners as they are browsing through a plant catalog or reading a gardening magazine. Wonderful descriptions of jasmines, camellias, and other warm-zone plants are just too tempting and too unfair to those of us who garden in colder areas. My weakness happens to be for Burford hollies, camellias, crepe myrtles, and jasmines. I would give away my eye teeth to be able to successfully grow these plants year-round in my zone 5b garden.

Mainly I think that the plants we most lust after are the ones that are "just out of reach" for our growing zones. For example, those plants I have confessed to wishing I could grow in my garden are hardy just into zone 7, maybe zone 6b for some cultivars. Just out of reach for all practical intents and purposes. But, there is a way to thwart some of the zone envies, so take heart!

I know of gardeners who have successfully grown plants out-of-range, but like any gamble, it is a toss of the dice. While it is true that most plants gain hardiness as they age and become acclimated to a growing area, some plants are just too warm-blooded to be realistically expected to survive despite all efforts at coddling. Wrapping plants, siting them just precisely for the optimal growing conditions, using the concept of growing in microclimates all help, but it is entirely up to the whims of Ma Nature if a plant will survive for the long haul. Given one or two ferocious winters, all those years of pampering often go straight down the tubes.

What are some of the options for us, then?

One approach is to look over that list of what we most would like to grow, but can't in open ground. Pare it down by deciding which plants can be grown in containers, and brought indoors to successfully overwinter. Now, that Burford holly isn't going to do well in the long run as a container plant, it will just get too big eventually. Same with the camellia. I don't want to kill any plant just to satisfy my own vanity. With those plants, I might be able possibly grow and overwinter them for a few years, then I would have to toss them when they became unmanageable. But, there are dwarf crepe myrtles that will do just fine in a container and can overwinter on a cool, frost free porch. That jasmine can be brought indoors as well, and both will respond to pruning. I just narrowed my lust list down from four items I would like to grow to two realistic choices.

Many tropicals have a faster growth rate than northern-grown native plants. Brugmansias, for example, can easily achieve a four to eight foot stature within several years. Taking that into consideration, pick plants that if they are rapid growers, will respond well to pruning. Plants that respond well to pruning, like that Brugmansia, can be kept for many years.

Another thing to look for are any plants that are dwarf in stature or very slow growing. I briefly touched on this with dwarf crepe myrtles. Many tropical or warm-loving plants do come in smaller or dwarf varieties. Pygmy date palms can be grown in a container, then brought in for overwintering. Certain fig trees can do double duty on the patio and indoors during the winter as well.

One overlooked opportunity that can afford year-round growing of plants is to do the old substitution trick: Do you want a large crepe myrtle permanently in the landscape, but can't grow it? Grow Seven Sons Flower instead. Heptacodium miconioides is the exact name, and it can and does grow rapidly and well in our region while offering colorful red bracts following a late-summer blossoming. It also has an attractive, peeling bark, and is much like the crepe myrtle in growth and appearance. It can be pruned vigorously, and can be trained to maintain a tree form.

Magnolias are a family of plants with a wide variation in hardiness. Many magnolias are hardy for our region. There are various deciduous, semi-evergreen, and some of the hardiest evergreen magnolias which can be substituted for the more tender varieties. If you really must have a true Southern Magnolia, consider the hardier cultivars such as 'Edith Bogue', 'Victoria', or 'Bracken's Brown Beauty'. I have 'Victoria' growing in the open ground in a protected spot, and it is putting on new growth. It will probably never attain the stature of more southern-grown specimens and it may not flower reliably, but it is doing well for me. 'Henry Hicks', a form of Sweetbay Magnolia, is an easily grown semi-evergreen shrub or small tree. In some years, it will lose its leaves after a particularly harsh winter, but it bounces back with new growth. For the past two years it has bloomed in waxy and scented white blossoms in June. It closely resembles the true Southern Magnolia but with a scaled-down version of leaf and blooms. Deciduous magnolias offer many wonderful and hardy choices, including some now being bred to bloom in deeper pinks, peaches, and yellows.

That brings up another point: Look for hardier varieties of typically southern favorites. Hydrangeas, roses, rhododendrons, and azaleas come to mind. There are many cultivars specifically bred for harsher climates to consider. Just coming to mind is holly again. The Meserve hollies, 'Blue Prince,' and 'Blue Princess', are two evergreen hollies that will do well in our region, given the correct soil type, siting and drainage.

We might not be able to grow truly huge palm trees or bananas in the open ground in our region, but by studying growth patterns, hardiness of particular cultivars, overwintering capabilities, and good northern substitutes for southern plants, we can and should grow tropical-looking plants in our landscapes. It will help to alleviate the "zone envies" somewhat and will offer our visitors something surprising and unique to view when they come to call.

Share Your Gardening or Nature-Related Questions, Tips or Comments:

Through The Garden Gate