Supporting guidance for Control of Scrub or Woody Vegetation

This is an old version of the page

This is an old version of the page

Date published: 30 March, 2015

Date superseded: 28 May, 2015

Credit: Andrew McBride, Scottish Natural Heritage

Scrub can provide a valuable habitat for a range of species including birds and invertebrates. However, where scrub is expanding into other habitats it can lead to a loss of important species and plant communities, both by shading out or out-competing the existing vegetation or by affecting the water table.

Scrub encroachment onto peatlands (bogs and fens) is often linked with changes in the water table due to drainage, but changes in land management practices and surface disturbance can also encourage scrub. Established trees and scrub draw water out of the peat and also intercept rainfall in the canopy, some of which is lost to the atmosphere through evaporation. This drier peat then encourages the establishment of further scrub and trees, the release of nutrients from the peat and also captures nutrients from the atmosphere.

Scrub encroachment can also be an issue on species-rich grasslands and on a range of heathland and wetland habitats.

As part of your application, include information on your scrub control proposals including: the species and location, the extent (area and percentage cover), the nature of cover (light, intermediate, heavy), the age of the scrub (young, mature, old), the proposed methods of treatment, what you will do with the cut material and your follow-up methods.

You will need to submit a Scrub Control Plan as part of your application.

Under certain circumstances a Forestry Commission Scotland felling licence may be required to remove areas of woodland under peatland restoration plans. Contact your local conservancy office for advice.

Hand pulling

Hand pulling can cause ground disturbance that encourages further germination of scrub so it is only appropriate where seedlings are small and thinly spread.

Cutting

Hand cutting and lopping may be appropriate for clearing small areas. For larger scrub control projects brush cutters and chainsaws are effective. Brush cutters can be used on scrub with a basal diameter up to five centimetres, for larger scrub a chain saw is more efficient. Stands of scrub over 1.2 metres high should generally be cut rather than sprayed as above this height there is increased risk of spray drift or operator contamination.

Cutting alone will not kill the scrub, and many species will regrow from cut stems in the following spring. To reduce the chance of regrowth cut stumps should be treated immediately with an application of 10% solution of glyphosate – this is particularly important for birch. Treating immediately will allow as much herbicide to be taken up as possible, preferably within one hour. Mix this herbicide with a water-soluble dye so you can see where you’ve been. Apply it with a spot gun or small handheld sprayer on a solid jet setting to reduce spills and damage to the surrounding vegetation.

Cutting should be carried out between 1 August and 28 February to avoid the bird breeding season and when the sap is falling to maximise the effectiveness of stump treatment.

Cut material

On drier habitats it will be possible to extract the cut material. On sensitive wetland habitats, such as bogs and fens, it may be less damaging to fell to waste some or all of the scrub and to leave the cut material to be gradually incorporated into the bog surface. Where this is the case, felled material should be cut into one metre sections, snedded and left lying flat on the bog surface. This promotes rapid inclusion in the bog. Cut material may be used to infill ditches, using the trunks to weigh down brash.

Flailing

It may be possible to flail dense scrub (gorse and rhododendron) at the edge of a site. The cutting can be collected and burnt on corrugated sheets or composted.

Spraying

For small areas of scrub regrowth where cutting is not possible, spraying is an alternative. We recommend you spray in summer and, to reduce damage to the surrounding vegetation minimise the risk, spray only on calm days. To further reduce damage to surrounding vegetation, weed wiping is preferable to spraying, but it is only effective with light birch regrowth.

Herbicide can be applied with a pneumatic sprayer or a low volume sprayer. Most woody species found on bogs can be treated with glyphosate. Formulations vary and label recommendations should be followed at all times.

Where scrub is dense and impenetrable, for example with gorse and rhododendron, either spray from the outer edge in year one followed by a further spray treatments once the edge bushes / branches have died back or cut paths into stands to provide access.

Removal of cut material from the site

Where large amounts of scrub are to be cut it may be preferable to remove the cut material from the site. See Control of Scrub or Woody Vegetation – Removal from Site of Cut Vegetationfor further guidance.

Access routes

If using machinery on wet sites use low ground-pressure vehicles and only when weather / ground conditions are appropriate. Select routes through drier areas to minimise damage and brash to protect the ground surface.

Follow-up work

Without aftercare from either grazing stock or further chemical treatment, areas that have been cleared can regrow into dense, impenetrable scrub within a few years. It is essential that you undertake follow-up treatment to tackle any regrowth. There is a separate capital item option for follow-up treatment.