Pay particular attention to such trees, even to the extent of tying in those branches-especially of cypresses-which, if distorted out of shape, would spoil the appearance of the trees. Suckers In the Royal Horticultural Society's Dictionary of Gardening a sucker is described as a "shoot of underground origin". Such suckers often form an unsightly mass of vigorous shoots forming a ring around the base of a tree. A typical example is the growth of the common white-flowered hawthorn on which has been budded the double red cultivar. It is useless cutting these off at ground level for this only encourages numerous new growths to develop. The suckers should be severed at the point where they join the roots. If each individual sucker can be given a sharp tug back against the direction of growth this will sometimes suffice to remove it, but very often it can only be done with the help of a sharp-edged tool. Moving the soil to expose the base of the suckers and then getting to work on them with a sharp pointed trowel or small, sharp spade will prove effective. TREE SELECTION The selection of trees for your garden should be an enjoyable exercise. To settle on a final choice from the great number now available can involve browsing through books (preferably well illustrated); looking through nurserymen's catalogues which, it is pleasant to note, are nowadays much more than just price lists; visiting well-known arboreta-gardens renowned for their tree collections; and attending talks and walks organised by recognised authorities on the subject. Always, there are professionals ready to give sound guidance when problems arise. In the following lists (pp. 45 to 52) the trees are grouped under various headings. These should not be considered rigid classifications, as they allow for overlapping. Certain basic terms should be understood, but the amateur gardener need not concern himself with the jargon so freely used among professionals. It should, however, be appreciated that a standard tree for garden planting usually means one having a clean stem measuring at least 5ift(i.65m) from ground level to the first branch, while a half-standard hasa stem of about 4±ft(i.45m). These are the two sizes generally planted, and, for such practical reasons as the need to have the lowermost branches at a height which will not impede lawn-mowing, more standards are planted than any other kind. In a garden a full 5 acre (.205 hectare) in extent, space may be found for j planting some trees in groups of, say, three specimens. There is no reason why three different flowering cherries of similar habit of growth should not j form such a group, but it is not advisable to plant, say, one hawthorn, one maple and one crab apple together. (See also Chapter 2, p. 25, for more on this subject.) Planting distances cannot be standardised, but sensible spacing between individual standard trees in a group should not be less than i8f 1(5.5111).