Scrub, brush and woody weeds are a common sight across the UK. These weeds cause problems in forestry plantations, as well as areas of non-crop land managed by both public and private organisations.
Due to the nature of their growth, this group of weeds can be very difficult to control. Not only do they require treatment at different times of the year, they may also require a variety of control methods in order to achieve optimum results.
Young trees in particular succumb to the highly competitive nature of both grass and broad-leaved weeds. To minimise this problem the Forestry Commission recommend an area of one square metre is kept free of weeds around newly-planted trees.
In forestry and woodlands weed control is important both before and after planting. Where trees have previously been grown, weed invasion, particularly by bramble, broom, gorse and woody weeds, can occur.
Bramble, broom, gorse, rosebay willowherb and woody weeds can be effectively removed with products such as Timbrel* or Garlon* 4. Triclopyr, the active ingredient of Timbrel and Garlon 4 degrades rapidly in the soil, allowing planting to take place from six weeks after application. Timbrel and Garlon 4 are also safe to grasses. Not only does this provide vital wildlife habitats, it also prevents erosion and enhances the appearance of treated areas.
After planting new trees effective weed control is vital to aid successful establishment. Products like Kerb* Flo, can be applied to transplanted forestry trees at any growth stage, either pre- or post-planting. They have excellent activity on grass weeds and some broad-leaved weeds when used in forestry situations and can be used on all popular tree species without risk of damage to the trees. To broaden the pre-emergence activity and spectrum of broad-leaved weed control it is possible to tank mix them with Flexidor* 125.
The most active extension growth of trees is normally between April and June and during this time they are vulnerable to the effects of weed competition. On fertile soils in particular, woody weeds will develop at this time amongst the planted desirable species. Targeted applications of Timbrel or Garlon 4 should be made as spot treatments, always using a tree guard to protect the planted trees. Alternatively, basal bark or cut stump treatments are also a possibility. Overall applications can be made to some coniferous species, provided it is done during their season of complete dormancy.