Brilliant, hard working gum trees

GARDENING

Friday, we drove to Michigan along the 400 series of highways. Dark clouds blanketed the sky and the countryside was a monotone shade of grey, until the first woodland appeared along the highway. Brilliant yellow, orange and red foliage created walls of colour that refused to be muted by the gloomy weather. I watched the colours appear and fade as we drove along the highway: when a town appeared, dull greys and muted greens predominated, and when a woodland filled with maple, oak and other native trees, colours warmed the countryside.

Can a dull and dreary afternoon teach us anything about garden planning? I think it can. Just imagine how you feel when you see a patchwork of brilliant autumn colours. If colour has the power to brighten and cheer a gloomy highway, why shouldn’t we enjoy that same energy in our own home garden?

Over the past few years, I’ve been replacing older shrubs with woody plants that feature brilliant fall leaves, using native species whenever possible. To this end, let me introduce you to the Sweetgum and Black Gum, a pair of trees that brighten our garden with brilliant colours each fall.

Sweet Gum (Liquidambar styraciflua)

I was drawn to the Sweet Gum (Liquidambar styraciflua) at Carl Palleck’s nursery in Virgil. The nursery was selling out before closing it’s doors, and a conical shaped tree with luminous, starshaped leaves caught my eye — it was a sweet gum tree. Palleck explained this tree would grow to be a spectacular specimen, it would be trouble free and turn brilliant shades of red, orange, yellow and purple in the fall. He was right.

Native to the eastern United States, Mexico and Central America, the sweet gum is right at home in a sunny Niagara garden. It grows to be a large tree, 1824 metres tall with a spread of 1218 metres, so give it space. Young trees will accept some crowding, but they become less tolerant of competition with age, as the deep taproot and lateral roots develop. Young trees will develop quickly if given ample space and light from the start.

The tree has a pyramidal shape when young, gradually it develops an oval-round crown with a straight trunk. Glossy, deep green leaves with toothed margins feature five to seven lobes and a pretty star shape; can reach the size of your hand. Attractive, greyishbrown bark becomes deeply furrowed with age, branchlets have corky ridges.

In the wild, sweet gums are found in low areas with rich, moist soil. They will tolerate flooding, but not deep shade. They are a good choice for a windbreak because they accept a variety of sites.

The genus name ‘liquidambar’ means liquid amber, a nod to aromatic gum that seeps from the tree if it is wounded. Insignificant May flowers are followed by characteristic prickly green balls that age to brown over the season and hang on to the branches well into the winter. The seed is eaten by squirrels, chipmunks and birds. Heavily bearing trees can be a nuisance to clean up after, particularly if they grow near a sidewalk, but my tree does not produce many seeds so this has not been a problem.

The wood of the sweet gum has been used for lumber, veneer, railroad ties, fuel, pulpwood for fine papers, flooring and interior trim. The gum used as chewing gum, incense and in folk medicine.

At this time of the year, the Niagara Parks Botanical Garden features an allee of Sweet Gum trees at the entrance to the park and a grove of the trees beside the pond near the golf course.

Black Gum ( Nyssa sylvatica)

I can thank Lorne Fast, manager at the NPBG, for introducing me to the Black Gum (Nyssa sylvatica) on the grounds of the park several years ago. I was looking for trees with late season colour and the black gum is a real show-stopper. Also known as sourgum, pepperidge and tupelo tree, this hard working Carolinian native deserves a place in more local gardens.

Black gum reaches 15-metres tall (and occasionally up to 24-metres), and features a conical crown and a straight trunk. The simple, alternate leaves are leathery, and densely clustered at the branchlets. The small greenish white flowers are attractive to bees and pollinators. The bark is reddish brown and broken into deep irregular ridges and diamond-shaped plates.

Black gum grows in the wild with a mix black cherry, dogwood, tuliptree, hickory and oak; it is shade tolerant, will accept some competition and can exist on unfavourable sites. It is resistant to air pollution, salt, heat and drought and is not bothered by pests or disease, but deer and beavers may browse the twigs, foliage and young sprouts. It is not difficult to grow from seed and transplants well. It can be challenge to source, I suggest you head out early in the season. We found our black gum at Gauld’s Nursery in Niagara Falls.

The fruit of the black gum is favoured by foxes, racoons, deer, opossums and birds such as wood ducks, wild turkeys, robins, woodpeckers, mockingbirds, brown thrashers, thrushes, quail and woodpeckers. Seed crops are produced yearly.

The wood has been used is used for docks and wharves; veneer, containers and pallets.

Our young black gum is now in its third season and it is settling in nicely, with outstretched branches and glossy foliage. I’ve positioned it behind a seating area where we will appreciate the cool shade canopy in the summer and enjoy the brilliant fall colours as the season winds down. Theresa Forte is a local garden writer, photographer and speaker. You can reach her at 905-3517540 or by email theresa_forte@ sympatico.ca