Hedgerows enjoy potential new growth in Ontario

The European practice of hedgerows and hedge laying is slowly entering Ontario’s landscape.

During a recent Ecological Farmers Association of Ontario webinar, Jim Jones, a British ecologist and hedge laying expert, explained how a managed hedgerow can fulfil several roles within agriculture.

Why it matters: Managed North American hedgerows could provide a biodiversity and ecological boost to areas with diminished woodland coverage.

“Hedgerows can create a landscape with a sense of place. That gives you a relationship to the land you wouldn’t otherwise get,” said Jones, who now calls Ontario home.

North American shelterbelts and windbreaks utilize deciduous trees with conifers on the outside to reduce wind effect. However, U.K. hedgerows are managed fence lines that provide ecological benefits and hold cultural significance.

“North American hedgerows tend to be the strips of vegetation that have remained within field boundaries, usually because fieldstone has been scraped to create a boundary and the woody species have grown up there,” he said.

“They’re the great habitats for wildlife, but they’re not really any use in terms of as a field (boundary) or livestock boundary.”

A managed hedgerow can play a massive role in biodiversity, said Jones, especially in regions with diminished woodland coverage, like southwestern Ontario. They can provide multi-species habitat and a microclimate from the grass boundary inward.

“When you’re starting to think about a new hedge row — doing it from scratch — you’ve got to ask yourself what it’s for, especially if (you’ve) had no concept of what a planted, managed hedgerow is all about,” Jones said. “You’ve got to think about what kind of function your hedgerow is going to perform.”

Coniferous trees are not ideal for hedgerows because they don’t respond well to coppicing, which is the process of cutting the tree at its base to promote rapid new growth. That is fundamental in hedgerow management, said Jones.

The backbone structure of a new hedgerow consists of 50 per cent of one species, like Ontario’s hawthorn, Osage orange or black acacia.

Hedgerow propagation doesn’t require ground preparation, although conditioning soil using turf stripping, plowing, spraying and use of landscape fabric helps. Transplants can be slot- or notch-planted into existing conditions, Jones said.

He likes a dense one-metre planting structure with five plants, ideally one or two-year-old whips, in two staggered rows 38 centimetres apart with 45 cm between each plant. Rabbit and deer guards are recommended.

“(Staggering) provides more structure as the hedgerow starts to grow. People are often surprised at how dense a hedgerow is planted, but once you come around to managing it, you see how important that is.”

Fit for Ontario

Although the availability of wood and barbed wire allowed North American farmers to drift away from labour-intensive hedgerow fencing, there was a resurgence in the 1840s and again in the 1930s to combat soil erosion during the dustbowl, mostly using Osage orange.

The thorny tree, which grows in Caledon but is threatened by the proposed Highway 413, is said to be “horse high, bull strong and pig tight,” making it an excellent base for Ontario hedgerow systems, said Jones.

The challenge lies in creating a cohesive list of species ideal for North American-managed hedgerows because European options aren’t necessarily viable.

To date, Jones has used American hazelnut, gray dogwood, chokeberry, nannyberry, arrowwood, serviceberry, black chokeberry and fragrant sumac in pilot hedgerows on Mount Wolfe Farm in Albion Hills.

In addition, Topsy Farm on Amherst Island also used Alleghany serviceberry, nannyberry, red oak, ninebark, hackberry, meadowsweet, grey dogwood, maple, highbush cranberry and chokecherry for its hedgerow.

Hedgerows have a circular lifecycle of 50 to 100 years before they become derelict and die. In the first 50 years, the shoots will proliferate from below-cut stems and thicken yearly, densifying interlocked branches.

At some point the hedgerow requires rejuvenation from the bottom, where hedge laying comes into play, said Jones.

Using stakes and binders, a “living hinge” is cut about four-fifths of the way through the tree near the base and is laid at a 35-degree angle between the stakes as a single-brush or double-brush system. Traditionally, if livestock is on both sides, a double brush system is employed.

He said a generous number of stems within the border is essential before laying a hedgerow.

The Ontario Rural Skills Network provides hedge laying workshops, as does Jones’ business, Hedgerow Co., which propagates indigenous species for hedgerow development.