Except for conifers and a few trees such as beech and hornbeam, most shrubs make better hedges when the leading shoots are removed to encourage side growth and establish a useful base. Most also make a better and quicker hedge when trimmed rather more frequently than usual in the first two or three years. Thereafter, annual trimming may be sufficient for most species although some make more formal hedges when cut two or three times each summer. When planting it is almost a necessity to use a garden line to ensure a straight run of hedge or to achieve a predetermined curve. A single line of plants is to be preferred as weeding or hoeing is then easier and the final growth and appearance better than with a double row of plants. Spacing of the plants depends on their vigour, on the intended ultimate spread of the hedge and on the cost of the plants. Some, such as Leyland's cypress, x Cupressocyparis leylandii, make perfectly good hedges when planted at 3 or 4ft(i or 1.25m) apart and when trimmed to a broad base of similar width. Others, such as privet, Ligustrum ovalifolium, and its forms, or escallonias in the milder districts, make good hedges very quickly from cuttings struck in lines at 9 or i2in(23 or 30cm) apart where the hedge is to be grown. Similarly planted seedlings of quickthorn will produce useful hedges in a very few years. The provision of slight shelter for the new hedge by planting against fine mesh wire netting or, in very exposed situations, lath fencing, can produce a good screen more quickly. If really necessary, the young growths can be tied to the fence in order to encourage upward growth. Such temporary fencing can be left within the new hedge and thereby provide some stability in the early years and prevent the passage of unwanted animals. PLANTING RECOMMENDATIONS Almost any shrub or tree can be planted in rows to produce an informal screen, but the number of species suitable for the production of formal hedges is more limited. Plants for use as formal hedges need certain characteristics: an ability to withstand regular annual-or more frequent -clipping; and a main stem, or stems, from which grow many branches that remain alive as the tree or shrub grows upwards. The more restricted the root run the more acceptable the hedge plant as it is then less competitive with plants in neighbouring beds or borders and with the grass in adjacent lawns. Evergreens, or those deciduous shrubs which retain their dead leaves through the winter, have an advantage in many situations. The most satisfactory will now be examined. Conifers for Hedging The common English yew, Taxus baccata, forms the background and frame of many of the stately gardens of this country. It is the standard formal hedge with which others are compared and is still worthy of consideration where such conditions are desired. Its branches stand regular clipping and even with perpendicular sides they remain alive and green for many years.