The ground must be prepared properly so that the new hedge plants establish and grow away well, shading out competing growth after a couple of seasons. Where ground preparation is poor, the plants will struggle to make growth, and weeding will remain a problem for several years.
The soil should be friable with a good tilth, so that roots can establish easily. A free draining soil with a high content of organic matter will give the best growth, though such conditions are not always possible. The ground must be free of other growth, and weed control will be required for at least two years after planting.
The amount of ground preparation required will depend on the soil conditions. Previously cultivated agricultural land or garden soil should have a good tilth, and may simply require weeding or removal of turf before planting. In previously uncultivated ground, or where the soil is heavy clay, very stony, or on a highly disturbed urban site, more work will be needed.
Dig a few test holes along the line of the proposed hedge, to check the soil conditions. If the soil is deep and friable with overlying turf , the turf can simply be removed or sprayed with herbicide, and the hedge planted. If however there is only a thin soil layer over heavy clay or subsoil, then the ground will need digging over, and plenty of compost, manure or other organic material added as available. The quantity used will depend very much on the supply available, but aim to add about one cubic metre of organic material for every 5 cubic metres dug over. Rough grass can be mown for the summer prior to planting, and the resulting turf then removed as above. If the ground supports growth of perennials such as nettles, brambles or bindweed, these will either need digging out or treating with herbicide.
For heavy clay or other difficult ground conditions, if possible start preparing the ground a year before planting. During the first winter, leave it rough dug for frost and weather to work on it. In the spring, spread a thick layer of manure or other organic mulch to keep the weeds down, and to be dug in nearer planting time. Treat or dig out perennial weed growth. Where the soil is good, it’s best to leave the cultivation until just before planting, to avoid leaving the soil exposed to erosion and spread of weed seeds.
Marking out
Allow sufficient width for the type of hedge you are planting, taking particular care with hedges beside paths, roads and drives, and ensuring that sightlines at driveway entrances will not be obscured when the hedge is fully grown. As shown in the diagram opposite, untrimmed ‘wildlife’ hedges will take up considerably more room than trimmed, stockproof hedges.
The cultivated strip in which the hedge is going to be planted should also be generous. The old advice (Beddall, 1950) was ‘dig wide, dig well and dig deep’. The plants will establish best if they have a deep and wide root run of cultivated soil. It’s also very important that this ground is kept clear of other growth, either by weeding, mulching or herbicide, so that competition from other plants for water and soil nutrients is removed.
For digging and planting by hand, mark each end of the planned hedge with two temporary stakes, placed at the corners of the strip to be cultivated. Mark any definite changes of direction between the stakes along the edges of the strip. Then, with one person to sight between the stakes, another person places canes or similar to mark the outer edges of the strip. When planting along a boundary of land ownership, make sure you follow the correct line, allowing sufficient room for growth, and for any maintenance needed on the side adjoining the boundary. For curving lines, make sure the curve is smooth, using strings as necessary. Then take time to look at the marked strip on the ground, making sure it is exactly as you want it, as the hedge is hopefully going to be there for a very long time!
Where a tractor is being used to prepare the ground, the operator should be able to plough a straight furrow, or follow a smooth curve. Mark the start and end points, and any definite changes of direction as necessary.
Removing vegetation
When deciding how to prepare the site, try and plan ahead. For example, rough grass can be mown regularly through the previous summer to convert it to short turf, which is easier to deal with. Regular mowing discourages perennials such as nettles and bindweed. The turf can then be removed and either relaid elsewhere, or stacked to rot, or where the site is being double-dug, cut up and put in the bottom of the trench. When stacking turf to rot, stack the turves neatly grass-side down, and cover with a black plastic sheet to prevent regrowth. In six months or so it will have rotted down to a rich, crumbly soil.
As an alternative to removing the turf, it can be sprayed with a herbicide such as glyphosate. This needs applying in late summer to early autumn, while the grass is still actively growing. The grass will turn brown and form a mulch which protects the surface of the soil and discourages the germination of weeds. If troublesome perennial weeds such as creeping thistle or bindweed appear in the interval before planting, they should be spot treated with herbicide. The hedge plants can then simply be slot planted through the dead grass. This should only be done where the underlying soil is deep and friable. Hedge plants slot planted direct into heavy clay or other difficult soils will not thrive.
Unwanted woody plants along the proposed hedge line should be cleared and the ground thoroughly dug over to remove all roots. Bramble, bindweed, climbing hop and other vigorous scrambling plants are difficult to remove, but will rapidly regrow to smother a young hedge if not kept in check. Thorough hand weeding or herbicide use will be needed to control growth during the first few years after planting. For a wildlife hedge, some existing woody growth can be left where it does not interfere with the establishment of the new plants.
If possible, cover bare ground with an organic or plastic mulch to protect it and keep it weed free in the interval until planting (see below).
For machine cultivation, existing vegetation can either be removed by ploughing and cultivation, or by use of herbicide followed by cultivation.
Double digging
In heavy clay, or soils with a ‘hard-pan’, double-digging may be necessary, together with the addition of organic matter as available. A hard pan is a hard layer of soil which restricts drainage and is difficult for the roots to penetrate. It occurs naturally in some soil types, and can also be caused by repeated cultivations to the same depth in the soil. The hard pan should be broken up by hand digging or machine cultivation.
To double-dig:
- Starting at one end of the marked strip, dig out a trench across the end of the strip, a spit deep and about 2-3ft (600-900mm) wide. As you dig, remove roots and weeds, and throw the soil into a barrow. This soil is then barrowed to the other end of the strip, or, for group work, to the next point where digging is commencing.
- Fork over the exposed bottom layer to another spit’s depth, breaking up any hard pan with a pick axe if necessary. If turf has been stripped and is not wanted elsewhere, this can be placed grass side down over the forked layer and chopped up. Add farmyard manure, compost, composted chippings or other organic material as available, spreading it over the forked layer. As a rough guide, add about one measure by volume of organic material for every five measures of soil dug over in the top spit.
- Repeat step 1, but throw the soil forward so it covers the lower spit in the first trench.
- Repeat step 2, forking over the lower spit in the second trench and adding organic material. Proceed until the strip is finished, using the barrow of soil to finish the last trench.
It is usually advisable to prepare the ground a couple of weeks before planting, so there is no risk of delay in planting when the hedge plants arrive. If there is going to be a delay of more than this, it may be advisable to cover the cultivated strip with organic or plastic mulch, to protect the soil from erosion and spread of seed. Rolls of sheeting, for example 100m x 1m width, designed for mulching hedges, are available from suppliers of hedge plants, and can be used both before planting, and then left in position for 2-3 years to act as a mulch. The hedge plants can be slot planted through slits in the sheet.
Alternatively, it is possible to double-dig and plant at the same time, but this does require careful team work. While one person double-digs as described above, another person positions the plants as the trench is backfilled. Follow the planting advice. The person planting should have a stick marked with the distance from the edge of the trench to the planting line, and in addition the digger should keep sighting along the line of plants to check their position. For double row hedges, two pairs can work together, each doing a line of plants. The hedge plants should be checked for firmness after a couple of weeks or so, after the soil has had time to settle.
On suitable sites, a hand operated rotavator can be used instead of digging by hand to prepare the ground for planting. However, rotavators work best in soils which are already fairly friable, and may struggle to cope with soils with a high content of stones, clay or roots, or where the subsoil is near the surface. Rotavators can be hired from tool hire companies.
Machine cultivation
Farm hedges or longer lengths of hedge around playing fields, in parks and other large sites are most easily prepared using farm machinery.
On arable farmland, the strip of the proposed hedgerow can be ploughed and cultivated at the same time as other operations. Where the adjoining field is being sown in the autumn with winter barley, wheat or oats, this can also be sown across the line of the hedge. In the early winter, the hedge can then be planted by hand or machine into the young cereal crop, which then provides a nurse and shelter for the new hedge during the following spring and summer (MacLean, 1992).
On rough grass and other non woody growth, the easiest option is to cut the line of the proposed hedge by machine during the summer before planting to produce a grassy sward, and then use glyphosate to kill this off during late summer. This can then be ploughed and cultivated in preparation for planting the hedge.
