In the GARDEN

Northern Advocate, 27 March 1937, Page 14

In the GARDEN

[BY "TAINUI"] .|

MAKING A ROCK GARDEN.

The present is a good time for making a rock garden or for overhauling an old one. Reasonably dry weather is best for this work, as the soil and rocks are then easier to handle. If the rock garden is planted before winter sets in, a very fair show of bloom may be expected in spring and early summer. Dwarf annuals will be needed to fill some of the pockets until the slower growing perennials become established: The advantages of a rock: garden have been mentioned many times. Many plants are shown to advantage that would be lost in the open border. Each plant may get the soil it requires by preparing suitable pockets, which may have different soil mixtures. The plants may be more easily protected from wind and frost. Drainage, which is an important factor with so many plants is perfect in a well made rock garden. Care should be taken to remove all bad weeds, from the soil that is to be used, particularly such weeds as convolvulus, nut grass, twitch, oxalis. 'etc. The rockery would have to be pulled to pieces to remove such bad weeds once they had a hold under and between the rocks. Do not forget to put aside some good surface soil to surface dress the rock garden. Large rocks are more effective than small ones, and the weatherworn lichen covered rocks are more beautiful than those that are newly broken, and have hard cutting surfaces. When building a rock garden in a shady place for ferns and some flowering plants that like shade, the stones and punga stumps, covered with close green moss, that may be found in the bush are excellent.

Most alpines and true rockery plants like a position facing the sun. A bank or slope facing East or North is ideal. As drainage is important, the subsoil should' be well worked up with a pick. On top of this put plenty of small stones, then a layer of well-rotted garden compost, manure, or leaf mould, and over all, good loam. This arrangement will suit most plants, the top layer being varied, if necessary, to suit different plants. Gardeners who have not had experience with rock garden plants will not know that a great number are very deep-rooting, often sending long roots down several feet. From their appearance above ground, we have the impression that those plants that make a close mat on the surface will be surface-rooting. Such is not always the case. For some plants two rocks may be placed quite close together to form a cleft, and the opening nearly filled with soil. When the long roots go down between the rocks the plants grow out over the rocks in a beautiful and natural way. Care should be taken to partly bury the rocks firmly in the ground, and place them so that the water will drain to the soil below. There is no definite rule as to the size of pocket, which should be varied if desired, some being just cracks as already stated, and others up to four or five feet so as to hold a number of plants of one variety. As soon as the ground has settled the plants may be put in. During the wet many plants on an established rock garden have made rapid growth and will need cutting back. Some will need lifting and dividing, and others worn out, and should be replaced by new plants. It will be an advantage to remove

some of the top soil in the pockets and • replace by new. Well rotted manure mixed with soil may be needed fof some plants. Following are a few only of the many rockery plants that may be put in now. Aster alpinus, dwarf campanulas, dianthus of several species and varieties, cyclamen, erinus aipinus, gypsophila, helianthemum (rocW roses), leuchera, linaria, perennial ana annual, lithospermum, a deep rooting* v plant that does not like lime, nierembergia, dwarf perennial phlox, dwarf veronicas, thymus seryllum, sedrums, saxifraga, violas, mesembryanthemums, ajugqf arimeria, aubretia, silene, tunica, verbena chamaedrifolia. And there are a number of dwarf growing irises that are suit* able, and the following are a few suitable bulbs. Nerine, saillas, tritonias, chionodoxas, hyacinths, dwarf narcissi, &nenome, babiana. * NEMESIAS, For a bold show, nemesias can hold their own with most annuals. But they must have a well-nourished soil and a sheltered sunny frost-free position, particularly if early blooms are wanted. And the drainage, of course, must be right. Nemesias do not like* frost or cold winds. The large-flower-ed kinds, these of the grandiflora type * are splendid for a bold show. Seed may be sown in boxes, or it may be broadcasted, and the seedlings transplanted. It is much more satisfactory to sow in shallow boxes. Keep the boxes in a warm sheltered place, and prick out the seedlings, when large enough, into boxes of good soil. A box of the usual size will hold about four dozen pricked out seedlings. ' Keep the seedlings in the boxes untiig they have made good rooting. While they are in the boxes, loosen the soJj». about them, using a pencil or a nail. They will appreciate this little* attention. i Nemesias give best results in good, well manured soil, though they will do fairly well and look nice in any ordinary soil. In the preparation of the soil, I have found the following a good plan. Dig the bed a good spade deep, and put in the bottom a solicL layer of grass, either cuttings or long grass. Then build the top soil up to w 2 or 3 inches above the other soil level, at the same time working in a little super. This should be done two or three weeks before planting. The fermenting grass gives enough bottom heat to encourage root-action, which means growth. Put the plants in the bed not more than 6 inches apart LINARIA. Linaria is a very useful little plant and easy to grow. It makes a very pretty bed. Seed may be had in separate colours; the mixtures too are good. Sown in the open ground now they should do well. They are not faddy about the soil and do well in* full sun or with a little shade. They do not like too much manure, and they like good drainage. The violet shades look well with primula malucoides or with Virginian stock.