One of my readers from the Sustainable Future yahoo group (now defunct), Tres English, is interested in introducing forest gardening techniques in urban areas. Specifically, Tres asks "How would forest gardening principles apply to a linear forest?" In other words, the question is how to use edge areas, such as the shoulders of roads (known as verges in the UK) and the land areas between divided highways and such.
I previously posted on urban and other areas where forest gardening would have to be on a very small scale in Size doesn't matter - at least in Forest Gardening. Now I want to focus even more closely on the question of linear spaces. For that I turn to my forest gardening friend from the UK, Frank Bowman, for his insights. I'll then follow with some of my own thoughts.
It turns out that Frank has been thinking of this very subject recently, and really likes the idea of planting hedgerows of a biofuel plant - Willow (Salix viminalis and other varieties) - that could be easily coppiced, as well as help control traffic noise. In fact, he has been doing just that and finds a sense of justice in doing so. "It'd be a bit of justice too, to have renewable fuel growing and soaking up the co2 alongside where the co2 is being emitted!"
The photo immediately below is of Frank Bowman planting a willow forest by the hut.
"I think it would be a very easy novel idea to plant bio-fuel willow on the road grass verges. There is an awful lot of land on those verges throughout the country!The photo on the left shows dry Willow and the photo on the right shows the bunkhouse kitchen ceramic stove which uses one or two 15 kilogram bundles of willow per day. You can click on the photos to get a larger image.
One easy free source of Willow is that there are lots of viminalis and fast growing willow growing wild to be had for free to cut the branches and use, from the hedgerows, and lots of places in the countryside, close or alongside those very verges!
I'm in the photo here, last month October, and I saw an overgrown field hedge nearby and cut about 150 branches from it to add to the 'willow forest', I planted in our field. having come with a lot of 3' long branches to plant (simply stick them in the ground 1m apart). It didn't take me long to plant them at all. In all I planted about 400 trees in about 3 hours, and it was very enjoyable, being so productive, and I cant wait to see the growth next year.
I also planted two dense thickets around the field hut, to provide it with woodfuel close by!
Ive attached photos of the willow coppice field at Ragmans lane Farm and a photo of the ceramic stove willow burner, which uses 1 to 2, 15kg bundle loads of willow per day for the 18 person kitchen and bunkhouse. The figures that they gave me for the Viminalis yield, was for 1 hectare of land, the Viminalis Dry yield = 10 to 15 tons per yr, and wet yield = 20 to 30 tons." --Frank Bowman
According to Buckingham Nurseries, "Let the hedge develop normally for two or three years, then cut down one row to ground level one year and the other the next. By continuing this pattern, this will maintain a vigorous growth habit and it will control the overall height of the hedge."
In addition to being a fuel source, Willow can also be used to make baskets, and many varieties can make for colorful windbreaks.
This photo is of Osier Willow providing an informal screen at the Garden Centre of Buckingham Nurseries.
If Osier Willow (Salix viminalis) is used, the cut wood (withies) could be sold for basket-making. A vigorous variety such as this also offers excellent wind protection. If Golden Willow (Salix alba Vitellina) is used, this will produce outstanding yellow stems, and Scarlet Willow (Salix alba Chermesina) will produce brilliant orange-scarlet stems. By adopting this method of maintaining the hedge, a continuous windbreak will be achieved and one will gain the advantage of the very attractive colours of the young stems; and if the withies are sold this will provide an income from the hedge without detracting from its useful qualities." -- Buckingham NurseriesTim's Comments
In North Carolina, where I live, the idea of using roadside verges and the strips of land between divided highways for special plantings has been around for well over a decade. The efforts here center around "beautification." Most often, they use non-native wildflowers (although that is changing) or flowering small trees / large shrubs such as Crepe Myrtles. These areas, especially the trees, are not planted thickly into anything resembling a hedgerow, and are often well-manicured by the state or local government with regular mowings, and lots of artificial insecticides and fertilizers. The emphasis is on a very artificial definition of beauty, where the wild is not appreciated, and neat & orderly rules the day.
There is nothing wrong with beautiful scenery, but beautiful isn't necessarily useful.
Planting actual hedgerows is not done at the moment, but hedgerows would make excellent noise barriers, as Frank suggests, as well as helping control (slow down) traffic in neighborhoods as Tres suggests. Hedgerows don't have to be very wide to work, and there would still be a layering effect, though a somewhat smaller one than you would have with a larger patch of land. Most importantly, hedgerows could be much more useful in addition to providing attractive scenery.
Hedgerows can consist of a variety of trees, shrubs and plants, many of them food bearing. Some food bearing plants you might consider for hedgerows include hazelnuts, dwarf apples, dwarf pears, plums and various berries, as well as some uncommon natives such as Pawpaws and Persimmons here in the USA.
You can do everything with a narrow strip of land that you can do to a much larger area in regards to forest gardening. You are just more limited in space. This might mean avoiding trees that grow very large at maturity (oaks, hickories, pecans, etc.) if the space is just too narrow. Consult a local arborist for help with this (most cities of any size now have arborists). Or maybe not, as I have seen roadsides in Charlotte lined with large oaks and hickories separated by 20 -30 feet each. I can definitely envision building hedgerows between them.
You can also include plants that provide shelter and food for wildlife, particularly native pollinators (which are extremely important, yet are currently experiencing declines). Or the hedgerow can be used simply as a windbreak, noise barrier and CO2 sponge.
For more information on building hedgerows, check out this page of the Buckingham Nurseries website.
What are hedgerows?
Here in the USA we don't have the tradition of hedgerows that they do in Europe, especially in the UK, Ireland and the Low Countries. Many Americans are unaware of the rich history or functionality of hedgerows.
Simply put, a hedgerow is a group of closely spaced shrubs, trees and other plants that form a barrier or boundary. Hedgerows often separate fields from roads, mark property boundaries, serve as living fences and are even used as a part of formal gardens. Hedgerows are intentionally planted and usually maintained by people for just such purposes. Over time, additional species will colonize hedgerows alongside the intentionally planted trees and shrubs.
Technically, hedges contain no large trees, while hedgerows are older and do contain large trees.
History of hedgerows
Julius Caesar, in 55 BC reported that the Nervi tribe in Flanders (in modern Belgium), were creating hedges of slender trees, brambles and briers in such a way that formed a defensive wall that could not be penetrated or even seen through.
There are historical records of hedgerows being created in the British Isles at least as far back as the mid 800s AD. Some still living hedgerows are known to have been planted more than 700 years ago.
Perhaps the longest hedgerow ever created ran some 2000 miles along the Customs Line in India during the mid-to late-1800s. It was created by the British and used to control the opium trade and to collect taxes. The Great Hedge of India "consisted of fences, stone walls, and above all a nearly impenetrable barrier of trees, thorny bushes, and hedges, with periodic guard stations." Eventually, the hedge was dismantled.
"The maintenance and laying of hedges in such a way as to form an impenetrable barrier for farm animals is a skilled art. In Britain there are many local hedgelaying traditions, each with a distinct style. Hedges are still being laid today as they are not only beautiful and functional but they also help wildlife and protect against soil erosion." -- Wikipedia article on Hedgerows
Modern and Future Hedgerows
Hedgerows began to fall out of use after WWII. However, a number of organizations have been created to preserve the history and craft of hedgerows, as well as to encourage their continued use. Some of these organizations are the Hedgelaying Association of Ireland, the English Hedgerow Trust and the British Hedgelaying Society.
Traditionally used as living fences to create barriers and boundaries, hedges also provided fuel for heating and cooking. Hedgerows can still be used for these purposes today, but can also be used to create wildlife habitat, encourage native pollinators, prevent soil erosion, capture CO2 emissions, and to provide food when planted with fruit- and nut-bearing trees and shrubs.
Information on planting hedgerows, including possibilities for what plants to use, can be obtained from the above mentioned organizations, as well as the following links:
Hedging Plant Selection - UK website of Ashridge Trees
Planting a New Hedge - part of the Buckingham Nurseries website
Index to Hedging Plants - part of the Buckingham Nurseries website
Edible Landscaping - not specifically on hedgerows, but is a great online catalog of food producing trees, shrubs and other plants, including many great candidates for hedgerow planting
Your selection of appropriate hedgerow plants will be largely influenced by your particular climate and circumstances. Read the back issues of this Forest Gardening series for more information.
A Caution or Two
I feel the need to offer a caution or two at this point. Be thoughtful in dealing with road edges and such. Ask your local officials if there are restrictions and regulations regarding how you can use them. Be careful and use common sense. I don't want anybody hit by a car while trying to plant a tree or pick blueberries. And watch out for power lines that often run in these areas. Consider the mature height of your trees and shrubs compared to the location of those lines.
I would not plant the verges of fast moving highways or busy roads with food plants. Instead, I would plant these areas for use by wildlife, especially native pollinators, to absorb CO2 emissions, to prevent soil erosion, and as noise and privacy screens. Neighborhood roads with slow moving traffic, as well as areas along greenways and sidewalks, would make more favorable areas for hedgerows concentrated on food producing plants.