USE OF MANURE

Wairarapa Times-Age, 19 May 1939, Page 3

USE OF MANURE

NOT ALWAYS GOOD. Mulch is the term that the gardener uses to describe any layer of material that is spread on the surface of the ground around established plants. Very frequently mulches have manurial value, and sometimes they consist of nothing but well-rotted animal manure, usually either cow or horse. It is, however, a complete fallacy to suppose that all mulches are applied for their food value. Even the manure mulches already mentioned usually have a secondary value in connection either with the retention of soil moisture or protection of the soil against frosts. In tlfe rock garden, rich mulches of animal manure are not advisable under any circumstances. They tend to encourage over-vigorous growth out of all relation to the natural characteristics of the plants, and not only is this unsightly in the rock garden, but it also tends to suffei’ badly during the winter. The best mulches for alpine plants are those which contain a large percentage of grit or small stones. Most rock plants, and particularly those with a somewhat straggly nature, would benefit at this time of the year from a mulch or top-dressing with a compost of about equal parts fibrous loam, leaf mould or moss peat, sharp silver sand and small stone chippings. The last-named may be either limestone or sandstone, the former if the plants are lime-loving, as, for example, almost all the alpine pinks, and many of the silver saxifrages, sedums, and sempervivums; and the latter if they are lime-haters, such as heathers, many pentians, and lithospermums. COVERING BARE STEMS. The object is to spread a loose layer of the compost to a thickness of half an inch not only around the plants, but also amongst any straggling stems. Covered in this way they will tend to make roots of their own, and contribute their share to the well-being of the plant. Moreover, the loose topdressing is a protection against frost to the established roots below, and will prevent them from being heaved out of the ground during a spell in which cold alternates with comparatively mild weather.

In all cases, the mulch should be spread by hand, and worked very carefully* around the plants. On no account should it be heaped over foliage, which would immediately rot, and possibly cause decay to spread to the rest of the plants. It is only bare stems which must be covered. The manurial value of such a top-dressing, though small, is quite adequate for the limited requirements of plants which are accustomed to fight for their living in the stoniest and least fertile parts of the world. FOR PERENNIALS AND SHRUBS. Herbaceous perennials, ornamental

trees and shrubs, and fruit trees would treatment, and, if mulches are to be applied to them, they must be of a much richer nature. Rather strawy, but well-rotted farmyard or stable manure is the best material, and this should be spread to a thickness of some two or three inches all over thq ground. In the case of all trees and shrubs, including fruiting kinds, the mulch should extend at least to the outer limits of the branches. It is all to the good if it can go a few feet beyond them, as the root-spread of a tree usually exceeds the branch-spread, and many of the most, valuable feeding roots will be on the outside of such a circumference. It is not always wise to apply manure mulches at this time of the year. For one thing, if the soil is of a light sandy nature, much of the goodness of the manure will be washed right through into the sub-soil by the lime the growth recommences next spring, and so, will be lost so far as the plants which it meant to benefit were concerned. On heavy soils this difficulty does not arise, but then the moistureholding properties of such a mulch have to be considered. This will do no harm to established trees and shrubs, but may cause rotting in the case of herbaceous plants, particularly delphiniums, pyrethrums, gaillardias, geums, and perennial scabious. In any case, great care should be taken not to spread manure mulches on top of stems and leaves, nor yet over the dormant crowns of plants, such as paeonies delphiniums, and lupins, which show no winter foliage. Be content to spread the manure on the bare soil, and, if this is of a heavy nature, delay the mulching of herbaceous borders until September or early October. Animal manure is not good for any bulbous-rooted plant, least of all for lilies. This does not mean this class of plant does not benefit from top-dress-ings. The stem-rooting lilies, in particular, delight in a good thick layer of humus-forming material spread around them in the spring when they are making their growth. Either leaf mould or peat may be thoroughly well rotted, and prepared from either beech or oak leaves. Big, soft leaves of the horse chestnut and sycamore types are worse than useless for the purpose. Peat, too, 'should be of a good horticultural brand and, contrary to leaf mould, not in an advanced state of decomposition. A really good sample of moss peat is as suitable as anything for the purpose, but it should not contain a lot of very fine dust or hard lumps. STEM-ROOTING LILIES.

The principal stem-rooting lilies are Lilium auratum, Browni, croceum, Hansoni, Henryi, longiflorum regale, speciosum, tenuifolium, Thunbergianam, Tigrinum, and Willmottiae. These may be mulched every spring with a three or four-inch layer of leaf mould or peat, which should be applied when growth is already six or seven inches through the soil. Similar, but lighter, mulches may be given to the non-stem-rooting lilies, such as chalcedonicum, martagon, pardalinum and testaceum, but not to candidum, the familiar Madonna lily, which like to have its bulbs exposed on the surface of the ground. Light mulches of peat or leaf mould, applied in August or early September, are also of benefit to tulips and hyacinths, and may be given even earlier if growth appears premature. The all too familiar tulip fire disease is most likely to make its appearance if the young growth just spearing through the soil has already been damaged by frost.