British horticulturalist/writer Lloyd (The Well-Tempered Garden, 1971) has an ingratiating, contrarian credo: ""there should be less written about time- and laborsaving ground cover and more about precious plants and how to make them happy."" From middle age onward, moreover: ""the tree, which has a possible future, perhaps a great one, may be more important than yourself, nearing your end."" Most of the separate pieces, however, consist of plant-by-plant instructions--for rooting hardwood cuttings, selecting shrubs, planning a mixed border--within a specifically British frame of reference (climate, varieties, even sources). The serious gardener can perhaps take pleasure, nonetheless, in Lloyd's expert appraisal of crab apple varieties--or, certainly, in his remarks on color contrasts, on the uses of ""armed plants,"" on the ideal width of a path. And one need hardly have turned a spade to appreciate his barbed observations on opening a garden to the public. But a more typical piece is one-part commentary, three-parts concrete and precise follow-through. The majority of week-end gardeners will find Alan Lacy's Home Ground (above) a good deal more congenial.