The coppice orchard system

Phil Corbett and his own root fruit tree project

I met Phil Corbett during a Permaculture design course in 1990. He went on to develop the following system design. Phil understood the importance of agro-forestry systems and sought to adapt the Forest garden model to a system better adapted to commercial vegetable growing.

This system is basically a cut and cultivate approach, by using apple and pear trees that are on their own roots, not grafted, it is possible to coppice them at regular intervals. This creates a clearing that is then used for the more light demanding crops. The rotation part of the coppicing means that there are continually trees at different heights and stages of production.

In 2006 I set up a Corbett system on a piece of my land in Brittany. The apple trees were supplied by Phil and produced using aerial layering different (known) varieties of apples and pears. Here are 2 films, sorry about the quality they were made a long time ago, in which Phill explains the system.

This is a photo of the tree that Phil is standing next to in the film, taken in 2016

My experiences confirmed that apple trees could be coppiced. I found that hazel trees as bushes created very dense shade, it would be better to have them as a single trunk or to replace them with something else. Phil advises planting lime trees (Tilia) instead, on a shorter coppice rotation and for their edible leaves. As far as my coppice orchard is concerned the whole system works very well. I planted broom (Cytisus scoparius) for the windbreaks on the east and west sides. To the north there was already a walnut (Juglans regia), there was no noticeable allelopathic interaction with the apple trees. There is also a chestnut tree (Castanea sativa) and an elder tree (Sambucus nigra). I used Elaeagnus angustifolia for the N fixing shrubs. These are not coppiced, it kills them, but pruned in august to release nitrogen for the surrounding trees.

The garden beds under the trees were cultivated using no-dig techniques, crop rotation and green manures. The apples and pears, summer pruned, are kept low for an easy harvest and open to allow light onto the vegetables. The shading from the trees has no noticeably negative impact on the vegetables, with the summers being more and more hot the opposite is the case. The vegetables fan their leaves from excess sunlight/heat much less than the open field vegetables.

The system produces apples, pears, hazels, elaeagnus fruits, vegetables, salads, root crops, fungi, mulch, firewood and most of it’s own fertility.

The following text was written by Phil in 2003 when he gave a course on the farm in Brittany.

This project is based on the unpublished work of Hugh Ermen, formerly of Brogdale Horticultural Experimental Station and now retired and breeding new varieties of fruit trees.

Hugh discovered that there are several advantages in growing apples on their own roots [OR], i.e. not grafted onto a rootstock. Those advantages are:

• better health - although not altering the basic susceptibility of the variety to disease

• fruit development is typical of the variety, giving:-

• best possible flavour

• best storage life

• typical fruit size for the variety

• best overall fruit quality

• best fruit set, given adequate pollination, fruit from OR trees have more seeds, indicating increased fertility.

• It is highly likely that the degree of self-fertility is increased.

The only slight disadvantage of OR trees is that most varieties are more vigorous than is usually wanted. This means that trees may make a lot of wood at the expense of fruit bud production, giving big trees that take a long time to come into crop. Conventionally this vigour would be controlled by grafting onto a dwarfing rootstock. With OR trees a number of traditional techniques are used to induce early cropping. Once cropping begins the tree’s energies are channelled into fruit production and growth slows down to a controllable level. The techniques which are usually sufficient to bring about cropping are:

• withholding nitrogen [which stimulates growth] and withholding irrigation [except in serious drought]

• tying down 1 and 2 year old branches to the horizontal. This induces fruit bud formation.

• Summer pruning [induces fruit buds]and avoiding winter pruning [which stimulates regrowth]

Once cropping has begun a normal feeding and watering regime can begin. The average cropping OR tree can be maintained at a size very slightly larger than a tree on MM106 rootstock.

Unfortunately Hugh’s O.R. trees at Brogdale have now been destroyed for redevelopment of the site. The ORFT Project is busy propagating OR trees for planting in our trial grounds.. In a year or two we hope to have OR trees for sale when we have filled our immediate needs on site.

OR fruit trees are just as ‘coppice-able’ as other trees, and may be useful where damage from gales, animals or vandals is likely. Without a graft union trees can be planted deeper, and multi-stem trees with a crotch below ground level will be harder to uproot.

The Coppice Orchard

‘Coppice-ability’ is also the basis of our "Coppice Orchard". This consists of OR trees planted in rows running north-south. When the canopy of the orchard closes, a north - south row will be coppiced and the land in the row used for light demanding crops, e.g. vegetables on a no-dig system, while the trees regrow. The trees either side of the glade will have higher light levels on their sides and produce more fruit buds. The next year another north - south row is cut but not the immediate neighbours as these will have the extra buds, so the next row for coppicing will be next-door-but-one. In other words this will be Alternate Row Coppicing. This process is repeated every year, creating a series of parallel , sheltered glades. Eventually the rows of trees forming the avenues between the glades will also be coppiced in turn, but by then the ‘glade’ trees will have regrown to form the avenues. As the trees regrow there will be glades at all stages of regrowth until the cycle repeats itself, and niches for plants suited to full light, semi-shade or heavy shade, creating opportunities for different types of land use. The number of years before re-coppicing [and so the length of the coppicing cycle] is one of the many aspects of the project that we will only learn by doing it. The exact timing of coppicing can be adjusted to suit the type of produce that is wanted most.

COPPICE ORCHARD PLAN VIEW

Apart from apples, the main planting sites of the orchard also have OR pears and plums, hazelnuts, and nitrogen fixing trees and shrubs.

Instead of just producing fruit the coppice orchard can produce a wide range of crops – small wood, fruit, soft fruit, vegetables, possibly cereals, fungi and the more traditional bees and poultry.

Another possible yield might be heat from Jean Pain type ‘heat heaps’ using woodchips and other shredded orchard wastes. These heaps slowly compost and can yield heat over 15 months, so that a heap the size of a garage can give enough heat to provide hot water and heating for a small house over two winters. And when the heat stops you are left with a large pile of compost!

There is an old Chinese proverb that says ‘fertility follows in the footsteps of the farmer’ which is reworked as the permaculture principle ‘Fertility Follows Attention’. In the coppice orchard there is the potential for producing a great range of our needs in a single system, and productivity should benefit from our attention not being divided between vegetable plot, orchard, woodland, etc. The rotation of crops avoids disease build-ups, and if all residues are returned to the site there should be a build up of fertility. The plan is to include nitrogen fixing and soil conditioning plants, insectary plants to support useful insects, bird and bumble bee nest boxes, small ponds for amphibians and hedgehogs and generally to maximize the natural diversity, and yields, of the site.

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Phil Corbett in my coppice orchard in 2016

NOTES ON THE COPPICE ORCHARD

Note: microclimate / species notes are from central UK experiences – change things around to suit your own conditions.

These notes are given as a template to be localised and individualised, rather than a set of absolute instructions.

When I thought of the term ‘Coppice Orchard’ I wasn’t thinking about the psychology of naming things. Now everyone has the idea of ‘orchard’ in their head.

‘Food Coppice’ might be better – it allows the mind to get away from the trees, and to think of the system as a coppice system, with its repeating cycles and relationships. But then there’s lots of non-food crops, so ‘Crop Coppice’ gets us away from food and leads into the contraction of ‘Croppice’. Any more ideas?

The system involves more than coppice - there might be permanent windbreaks, and permanent standard trees within the coppice area.

If transport vehicles are big enough to need a track, then that’s a good place to plant permanent trees alongside.

Workers and young plants might need shade, and plenty of times in growing we need to keep things cool.

USERS

When growing conventionally for distant markets it is recommended that you don’t have more than 5 different harvests in the year.

Specialist harvesting equipment, storage, etc. make more harvests than this less practical and less economical.

The c/o can give many different harvests. There is a built-in element of opportunism.

It is conceived as a largely hand-tool system. Useful machines will be barrows for transport and a shredder.

So the c/o will be most useful in labour intensive situations where a wide range of produce is needed – communities , farm shops, restaurants, etc.

These users will have they own likes and dislikes – the system is flexible and can handle them.

More Veg Wanted = more frequent coppicing and smaller tree crops; maybe removing some unpopular trees – OR trees can be cut back, lifted in winter, and replanted elsewhere.

More Fruit Wanted = a longer coppicing cycle; not coppicing all the trees in a N-S row; pollarding rather than coppicing: propagating more trees; trees trained as pyramids for high yields.

STARTING

Site:

Choose land under existing arable or veg production or at least with no permanent vegetation. This will avoid the problem of perennial weeds and grasses etc, that will take a lot of time to control otherwise.

If the land grows good veg crops it should be ok for trees.

Avoid low-lying frost pockets and land that has lasting puddles in winter. If this is all you have plant trees on mounds.

Converting Site:

If you have only grassland etc you should convert to vegetable crops first – the coppice ‘orchard’ is a vegetable growing system too.

The important thing is to get the perennial weeds out.

Areas of bush/perennial crops with no perennial weed probs could be planted into immediately.

Work out the pattern of n-s rows. Mark tree positions with poles in the ground to check you have it right.

Plant trees amongst vegetables or other crop – carry on cropping and planting vegetables and work out new rotations to fit the row pattern, new pathways, etc. Remember you won’t be coppicing for some time, but sooner or later you will need rotations that fit the new arrangement of rows.

Allow a square metre of undisturbed soil around each tree for good early root establishment. Mulch around trees or plant winter-actives around them, eg Spring Bulbs [eg Wild Garlic], over-wintered annuals, eg. Miner’s Lettuce.

Winter actives are busy when the tree is dormant, therefore no competition. [stacking in time].

Plant windbreaks if not present already – use n-fixers where possible, avoid using trees related to crop trees, to reduce disease.

Use evergreens in North and East [coldest winds] sections of windbreak, including Ivy.

Plant fruit bushes and perennials between trees as intercrop. If estimated coppice cycle is 10-12 years most bushes will be old by then anyway. Fruit bushes – currants, rasps etc- can be moved or propagated from easily.

Hazels live longer and get bigger and are part of the coppice trees mix.

NUTRITION

Most nutrition should be provided within the system – via ample numbers of N-fixers and mycorrhiza.

Inoculate tree roots with mycorrhiza by dipping roots into purchased mycorrhizal ’soup’. Include the windbreak if you can or make a home made ‘soup’ of good healthy woodland soil and rainwater.

Many species are good ‘distributors’ of nutrients in leaf fall etc, eg hazel, lime [Tilia sp.].

‘Within the system’ includes returning wastes to the system – kitchen wastes, human manure, wood ashes.

Watch tree and veg performance – adjust any deficiencies with slow release ground minerals, comfrey and other liquids, seaweed, etc.

Return all possible wastes to site – this might include using a row as a tree bog for human manure- decide on period of ‘quarantine’ before food is grown again. Bog year is probably best followed by a year of non-edibles – green manure or mulch crop - to be used on the next year’s food crops. Also wood ashes, paper and cardboard waste, etc. ‘Sheet Composting’ in fallow areas. Use high-carbon wastes as surface mulch; don’t dig in, 1 or 2 year old wood shreds to make a good compost.

Bury road kills, shot squirrels, etc, in tree bog year.

POLLINATION & INSECTS

Maximise flowering plant species, especially early and late season – to maximise insect population – both pollinators and predatory species.

Ornamentals are great if you have the desire, or the sales potential, and the space.

Many common herbs are good insect plants, eg. Marjoram.

Avoid flowering plant species that flower at same time as crop species, unless you’re cutting them anyway.

Bumblebees should be encouraged with nest sites – use the space of the Nature plots.

Ponds – great for insects - are probably best kept on the outside of the coppice area, or on large sites kept in “admin” areas, next to tracks, buildings etc.

STANDARD TREES

Plant any permanent trees and shrubs that will NOT be coppiced – eg Walnuts. These can be at ends of row or mid-row to make a break, if row is long. These can be sites for bird, bat and insect nest boxes, give shade and shelter to workers, focal/marker points, and, when big enough, tree houses. If an internal vehicle track is needed permanent trees can be planted alongside it.

FIRST TIME COPPICING

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As the young OR trees grow the well-lit area of the C/O will be reduced to ever smaller patches. When you think a larger area of well-lit land is needed you can start the coppicing cycle.

Decide on the row to cut well in advance.

Human manure and road kills should go into tree bogs 2 years before coppicing.

The year before cutting the area will be covered with as much mulch as can be found. Shredded twiggy stuff from all over the orchard, vegetable wastes, wood ashes, paper, etc.

Concentrate the wastes on the next area to be coppiced right thro the year – so plants in the new area start with good light and good fertility. The area will have had a lot of shade before coppicing so there wont be many crop plants in it – save and move any that are worthwhile if still there. Old plants / weeds may need mulching out with a light-proof degradable mulch like cardboard or paper.

Which row first?

One way is to plant more vigorous tree varieties together in one [ or more] N-S rows. That row will be the most advanced and shadiest row and an obvious candidate for the 1st coppicing. But don’t let the vigour factor over rule the pollination factor when it comes to where to plant the trees. See the plan view for pollination recommendations.

You don’t need to coppice all the trees in a row if you don’t want to – just a few may give you all the extra land area you need.

You don’t need to coppice down to the ground if you don’t want to - you can pollard, to leave a high stem to get new branches from.

However you cut do it when it is the best time for the type of tree. Apples & Pears in dormant season [Dec-Jan is best ] and stone fruits – Prunus species – in September. These timings reduce the possibility of disease infection.

Leave cuts sloping so rain runs off.

Tree Propagation

Coppiced trees will have more roots than they can support. Locate roots [6-30 mm diameter] near surface and sever them from main stem leaving most of root buried. Raise the cut end of the severed piece into the light, leaving about 1 cm exposed. This will make a new tree. It will be removed next autumn and planted in the orchard or a nursery bed. Do this only with roots that are obvious near the surface – leave the rest for the tree.

AFTER COPPICING

The previous season you will have been sowing the area with plants for using as mulch this year. These will be mostly shade –tolerant large-leaved species – Burdock [cultivated varieties], Foxglove [Digitalis sp.] etc. These can be pulled up or have their roots severed, and the whole plant turned upside down, roots in the air, as a weed suppressing mulch between crop plants.

First year crop plants should be those that can go in as young transplants, widely spaced large seeds, tubers, etc. eg potatoes, beans, onion sets, brassica plants, outdoor tomatoes, leeks, cucurbits, i.e. avoiding subjects that might get lost in the mulch. Beans are useful for keeping up the nitrogen supply – remember next years mulch material will go to another row. Several crops will overwinter onto Year2 – garlic, leeks, brassicas.

Regrowth from coppice stools might give too many shoots – single out to best one [or how ever many you need]. Easy to rub out new shoots when they are small.

Season 2. In this year the mulch will largely have broken down into the soil. We can lift any young trees we made in year 1. Lifting trees and deep veg like potatoes gives us patches of bare soil for sowing roots, eg carrots, parsnips, beetroot.

Keep using n-fixing crops in gaps to maintain fertility.

The coppice stools will have made strong new shoots. With species like hazel and alder these might be bent over to make the frame for a plastic cloche to give us earlier crops. I wouldn’t advise this with fruit trees for fear of fungus problems. A small cloche could raise a lot of early seedlings.

A more permanent glasshouse-type structure might occupy on of the tree spaces near the centre of the system, possibly with covered area for doing outdoor jobs in comfort, tea in the shade, etc.

Last year’s new shoots on coppice stumps will now be growing laterals [branches].

Season 3: New shoots of coppiced trees may have fruit buds now. If so check that stems are strong enough to hold up under weight of crop. Stake if floppy. Remember the basic training techniques for OR trees – tying down and summer pruning when the tree is big enough.

As there will now be 2 newer rows producing veg so think about putting in strawberries and other soft fruit.

From this point on its hard to predict growing activity – play it by ear /see what happens, until we get to the tree bog stage again.

Phil Corbett, Kerzello, August 2003

NOTES ON THE COPPICE ORCHARD PLAN VIEW

The plan is an aerial view of the coppice orchard.

Species and climate notes are for central UK, adapt and evolve to suit your own conditions.

Each tree occupies a square of about 4 or 5 metres per side.

WINDBREAKS

The coppice orchard is surrounded by windbreaks. If you already have tall hedges, woodland, high walls, etc as a border, you may not need a windbreak.

Windbreaks are used to raise temperature on the sheltered side by reducing wind chill. This is important for pollinators as well as plants. In very bad weather bumblebees will choose the more sheltered sites. The coldest winds come from the East and North and on these sides evergreens are used for the best protection, including leylandii and evergreen climbers to help fill the cracks.

Windbreaks also prevent mechanical damage by reducing wind speed. Trees are most vulnerable to damage when they are fully laden with fruit in September. Damaging gales come from Southwest through to Northwest, but are not cold winds, so a deciduous windbreak is ok here, with the benefit of letting the sun through on early spring afternoons.

A windbreak across a slope will cause cold air to dam up above it, possibly creating a frost pocket. Allow for good air drainage.

The windbreak contains a lot of N-fixers, in fact it may be entirely Alder, with Eleagnus or Gorse at the base as draught-stoppers. These will not only grow quickly but some of their N will feed into the system. Mixed species of Alder are less vulnerable to disease than a single specie – avoid a monoculture.

Windbreaks and the land next to them may hold standard trees that we do not coppice, eg, Walnut, Chestnut, Oaks, Pines.

N-TREES

Within the system are numbers of N trees. These are Nitrogen fixing trees and these will be either Alders or Black Locust [Robinia]. The N also stands for Nature and these plots will have other useful plants and structures, bumblebee nests, hedgehog boxes, etc. These plots may contain several trees.

Notice the arrangement of the N trees – every crop tree has an N tree next to it, except for those next to the windbreak, which are benefiting form the n-trees in the windbreak.

The staggered arrangement of the N-trees means that coppicing a row leaves the maximum number N trees standing in the system. When N trees are coppiced they release huge amounts of nitrogen. Make sure these areas have plenty of deep-rooted follow-up plants to make use of this, eg comfrey.

HAZEL

These trees are often found with Alders. They give a nut crop but also are useful as ‘distributor’ species with a mineral-rich leaf fall. Thus they will help spread the Nitrogen from their neighbour. As these will not get bigger than approximately 12 years of growth there might be 2 trees per plot.

FRUIT TREES

Note that this system has twice as many apples as plums and pears. This is a reflection of likely consumption. If you think you’ll need different proportions of fruit then plant to suit your needs. You might want mostly nuts and a few fruits, that’s fine.

POLLINATION

Notice the Apples are in a double row. This allows each apple to be next to 5 others, giving potentially very good pollination. The letters represent varieties. The 2 rows have a total of 4 varieties: A & B in the top row, and C & D in the lower row. The Top row has the ABBA arrangement and the lower row has the CCDD arrangement.

This means that when a N-S row is cut each pair of trees in the remaining rows will be different varieties, and still able to pollinate each other, or putting it another way, loss of neighbouring trees will NOT mean complete loss of pollinators.

Single row fruits, like the plums and pears here, should also be planted on the ABBA principle, rather than A B A B.

If you are planting lots of mixed varieties it will not matter so much. If you have only a few trees of a variety don’t put them all in the same n-s row, or you will lose them all till cropping starts again.

HARVESTING

It will make less work to have the varieties arranged according to season – e.g. all the early plums in one E-W row or half a row, the late plums in another , etc. This will concentrate transport in particular parts of the system, rather than running all around the system to collect all the early plums.

CHERRIES – there are none on the plan. OR cherries are not easy to control, Morello types might be more compliant.

I have grown sweet cherries from seed and I think they may be easier, but of course you don’t know what you have till it crops.

Cherries could be part of the ‘standard’ trees, or grown on dwarf rootstocks as permanent features in the system, or on colt stock as fans along edges, so they can be netted against birds.

By using Cool Temperate Plants and Services you are supporting this exciting project. I hope you will agree that it is rich in potential.

https://www.cooltemperate.co.uk

Thank you for your support.

Phil Corbett

Ps Phil unfortunately has some health problems which mean that there is sometimes delays in his replies.