This will ensure early and uniform growth. Suitable early training and regular trimming will then lead to the development of a successful hedge. In garden conditions it may be desirable to dig a strip up to 6ft(2m) wide for each new hedge. Compost or farmyard manure can be incorporated to improve the soil and the roots of perennial weeds can be removed. Annual and herbaceous perennial weeds can be a nuisance to newly planted hedges and cause poor bottom growth, but other shrubs, climbers and scramblers are the worst 'weeds' of hedges. They are mostly natives that spread from roots left in the soil during site preparation or by seeds from neighbouring plants. Among the worst offenders are elder, hawthorn and sycamore among the trees, and brambles, bindwood and dog rose that scramble through and damage both young and established hedges. All of these and other invaders need to be looked for each year and removed before a length of hedge has been damaged beyond repair. If soil preparations are adequate such dominant hedge weeds should not be troublesome in the first years, and the ordinary garden weeds can be dealt with by hoeing or the use of herbicides (see Chapter 38, "Weed Control", pp.332 to 339). Just as most hedges compete with neighbouring plants for food and water and thus cause loss of vigour in such crops, so, in the first year or two, young hedges may suffer from competition by weeds, or from lawns or other plants growing nearby. Weeds can be controlled but with newly planted hedges the effects of competition may need to be offset by additional feeding and watering if good early growth is to be obtained. When growth commences, training and trimming need to be started. All but very few hedge plants are better when trained to form a broader base and narrower top than the traditional perpendicular or more common rounded hedge pattern. A narrow-based isosceles triangle is the ideal sectional shape for most hedges. With such a slightly wider base the lower branches will not be killed by lack of light and the hedge will remain green to the ground. It seems so much easier to trim the lower branches too hard and thus produce a rounded sectional pattern to the hedge. A positive effort has to be made to leave the base lightly trimmed or untouched in order to encourage the suggested wider base and narrower top. For once inhibited by heavy trimming or by competing weeds or near by cultivated plants few hedge plants produce new growth at the bottom and the hedge remains for ever inadequate and unsightly. The advantages of narrow-topped hedges are in their greater permeability and in the limited space available on which snow can settle. The greater permeability allows the wind to filter through and reduces turbulence, while the limited snow cover reduces the risk of breaking open the hedge and damage to branches that can be almost irreparable. The frequency of cutting will, of course, depend on the subject which has been chosen for hedging, but a few general points are worthy of note.