Management of woodlands and hedgerows

Woodland Aftercare

Woodland schemes are sown in a wide variety of circumstances with varying degrees of shading and other effects from tree roots and leaf fall. For this reason the results of sowing seed will be quite variable. Establishment of ground cover can be slow and patchy and in deeper shade full ground cover will never reach 100%. The balance of species, and in particular the amount of grass growth, will be influenced by the amount of light available.

Established woodland:

Established woodland that has been under-sown with a woodland mixture may require little management during establishment. Establishment in woodland where light levels fall below 50% of that in the open is slow by comparison with sowings in the open. Some species, for example bluebell, take several seasons to germinate and 4-6 years to reach flowering. In the long term, ground flora will benefit from good tree management. Exclude stock and where appropriate manage the woodland as a coppice with standards, cutting sectors on a 20-30 year cycle.

Open or young woodland:

Open or young woodland with higher light levels will produce more growth and grasses will be more prominent. In these conditions an annual cut mid summer may be worthwhile for a more managed appearance and to keep weeds of semi-shade like nettles and brambles in check.

New tree plantings:

These will take 10-15 years for the canopy to close and for light levels to drop. During this initial phase seed mixtures that have been sown should be managed as grassland (mown or tussocky). As ground cover declines and shade increases to 50% woodland plants will have more opportunity to thrive. This is a good point at which to sow additional woodland wildflower seeds.

Weeds in woodland:

The most troublesome 'weeds' in woodland are nettles, cleavers, cow parsley and brambles. These weeds being only partially tolerant of shade are usually more prominent in woodland edges and glades. Chemical weed control is not really an option in woodland and is not effective for these species anyway. Woodland management which increases shade levels (eg dense planting including under-storey shrubs) will help weaken these plants. Low numbers of weeds can be successfully removed by digging them out. Mowing in more open situations can help keep these weeds in check. Woodland 'weeds' tend to be associated with more fertile sites and as with grassland schemes heavy infestations of nettles or cleavers indicate high fertility levels which mean that weed problems are quite persistent and diverse results difficult to maintain.

Hedgerow and Margin aftercare

Hedgerows, woodland edges, rides, glades and other semi-shaded communities usually sit on the boundary between one habitat type (eg open grassland) and another (eg closed tree canopy). The management requirements of established hedgerow mixtures can be tailored to light levels and to fit in with adjacent vegetation types.

First year management:

In the first year annual weed growth should be cut back. This will encourage the development of a good perennial ground cover which will to help control problem hedgerow weeds like cleavers and sterile brome.

Management once established:

Zoned management of hedgerow margins frequently produces the best diversity of habitat structure: areas closest to the hedge or woodland boundary and those which are more shaded are left uncut in most years; areas that are further from the margin and more open can be managed as grassland habitat. For example in a 6 metre sown margin the 2-3 metres against the boundary should be uncut, the next 3-4 metres cut once or twice a year.

Hedgerow vegetation that is not mown or grazed each year will become rough and "tussocky" in character. It can form useful refuge habitat on corners and margins of a site.

To control scrub and bramble development, tussocky areas may need cutting every 2-3 years between October and February. For wildlife this cutting is best done on a rotational basis so that no more than half the area is cut in any one year, leaving part as an undisturbed refuge. Mowing established tussocky vegetation may require heavy duty cutting equipment: domestic mowers would not be tough enough to deal with the thick tussocks or woody scrub that develops. Tractor mounted flail mowers are suitable for large areas, petrol brush cutters (professional 'strimmers') are good for small or awkward areas.

Hedgerows and margins that are cut can be managed as grassland.