HORTICULTURAL NOTES.

Otago Witness, Issue 3275, 20 December 1916, Page 8

HORTICULTURAL NOTES.

By J. Gebbik

ROCK GARDENS. Rockeries and rock and alpine plants are fast gaining popularity, and there is no doubt it is a recreative and charming form of gardening, which can be indulged in by all who possess a few square yards ot mother earth. The primary use of the rock garden is for the cultivation of alpine plants, and those who take up their .cultivation to any extent usually provide for them some form of rockwork. The ideal spot for an alpine garden would bo a rocky slope such as may be seen on the hills arpund,_ where the rocks jut out from a deep friable soil, affording numerous nooks and niches in which the alpine plants may lie sheltered from the wind and catch every drop of rain and beam of sunshine. It is impossible to lay down any hard-and-fast rules as to the position, for we have such a variety of ptants to make our selection from that we are able to utilise them to the best advantage for almost any position we- can mention. But without doubt the most suitable position for the site is one fully exposed to the light and air, and, if possible, it should be free from the shade and drip of trees. In building or forming a rockery or rock garden it must be kept steadily in view that it is intended for growing rock and alpine plants, and that their well-being is the first consideration. A rockery is not made by merely throwing up a "heap of soil," placing a few stones over and about it, and then calling it finished by inserting a few plants between the stones. Under such conditions as these one would not bo liable to avoid failure, although one might be able to get the surface covered with some of the stronger plants which make rapid growth in any ordinary border. The most suitable material with which to build the rockwork is a stone that is not too hard, so that it will respond to the weather—one which will obsorb and part with tho moisture, and so help to keep the plants moist and cool during hot, drying weather. Nothing in the culture of rock and alpine plants is more essential than that they should be kept moist and cool. In forming the rockery, commence by putting in a good drainage of stones and chippings well mixed together with the soil, arranging the ground in such a way as to give the best possible results. In placing the stones always lay them so that the water will run into the rockwork, and so help to keep the plants moist. In forming pockets for the reception of the plants, make them of various sizes, especially large enough to mass several plants of one kind together, as by so doing a grand display may soon be had which will provide a more charming effect. In planting, small growing plants should occupy as much as possible the low recesses, planting the largest percentage of the stronger and v larger growing varieties on the highest parts. By adopting this method the rockwork will appear to be of larger dimension than it really is. As stated above, the rock garden is for the cultivation of alpine plants, and I had better say what an aipine is. Properly speaking, an alpine is a mountain plant, and for the most part these are of small stature. Besides the true alpines, there are many other" plants of small stature suitable for the rock garden. There is such a large family of plants to choose from that we can in a very short space of time select suitable varieties for each particular position, and no matter what the aspect of the rockwork, if well arranged and well kept it is impossible to look over it without finding something to interest us. Passing through Rosebank, Balclutha, a few days ago I was attracted by a piece of rockwork in the garden of Mr James Guest. Having obtained permission to inspect it closely, I found it to be one of the best examples of rockeries, proving that the builder knew tho requirements of the plants it was intended to cultivate. Though not of great extent, it contained pockets for 200 plants, and although only about six months built, many of the plants are in bloom, a few are past, and others are only in bud. A few of the most striking were species of androsace, interesting and charming plants growing about 2in high. Several species of dianthus —one, D. alpirius, was smothered with bloom, a perfect gem, about 9in high. Potentilla nepalensis, Hypericum, linarias, violas, and many other families were represented, besides an extensive collection of veronicas, numbering about 60 varieties. Mrs Guest takes great interest in these alpine plants, so we had a rather interesting chat upon their merits an<? facinations. There is no garden, however small, where a rock garden could not be formed. The banks of many a tennis _ court or other slops where grass is so unsightly during the hot, dry summer months might be turned into a rockery, and made an interesting and attractive object. OENOTHERA. The common evening primrose (Oenothera biennis) is a biennial which opens its sweetscented yellow flowers towards evening, and seed is so freely produced that they will become almost weeds in the garden. There are many species of these flowers, all hardy and beautiful in any position. Some are annual, others perennial, and of the latter Qi macrocarpa is a showy plant, producing large yellow flowers over a long period. The habit is dwarf, a little over 6in in height. ffi. rosea, the Mexican primrose, has lovely pink flowers, produced ih the greatest profusion for a period of four or five months. It grows about bin high, and is perfectly hardy. Seed catalogues classify it as an annual; but I know that it stands the winters as far south as Mataura. (E. acaulis is another trailing species, producing largo white flowers tinged with pink. CE. amcrica is one of the latest introductions, and, like all tho others, comes from America. Tho flowers are very large, snowy white, and produced in tho greatest profusion. 05: youngii grows about 2ft high with golden yellow flowers, and is a splendid border plant. They are all freely produced from seeds, and afford useful material for keeping a garden gay. PLANTING RANUNCULUSES AND ANEMONES. Comparatively few lovers of hardy flowers

realise the beauty of the ranunculus and anemone. The former is known by the common name of crowfoot. Amongst dwarf flowers these tuberous-rooted plants stand unrivalled for their brilliant and attractive colours. The individual flowers of the ranunculus are about 2in in diameter, compact and symmetrical, and most attractive colours, such as white, crimson, yellow, purple, and black. There are several sections of these lovely flowers, and all ore worthy of more extended cultivation. The anemones have larger flowers of nearly all shades of colour, which bloom in spring and early summer. The planting of these bulbs may bo done in autumn or in the spring. April and May are the months for planting, and the end of August for spring planting. The ranunculus .delights in light, rich, and fairly moist soil. Heavy soils should be deeply dug and left exposed to the weather as long as possible before planting, and there should be incorporated nt tho time of digging leaves, garden rubbish, and any material that would lighten soil of heavy texture. Light. rich soil is greatly benefited by a good dressing of well-rotted cow-dung, well worked into the ordinary soil of the garden. Although they do well in good open positions, better results are obtained when they •are planted in beds and borders that are partially shaded. The tubers may be planted in various ways, in individual row-s, as margins to beds and borders or in small groups or irregular patches in the border, where they associate well with other subjects in the early summer. They should be plerited clawside downwards, 2in deep and 3in asunder. _ A plentiful supply of water should bo given during dry weather in spring and summer. The tubers should be lifted as soon as the foliage fades and turns yellow. They should be dried in the eun, and subsequently be stored away in : and in a dry place until planting time again comes round. The anemone is another hardy plant worthy of more attention, and. like the ranunculus, thrives tinder similar conditions. They should be planted 3in deep and bin apart. Tho pop~py anemones produce large single flowers. They were introduced into England so long ago as the close of the sixteenth century, and gardens -have been enriched and beautified by its presence continuously since that Deriod. Both Dutch and French gardeners have contributed to the improvement of the flower, and. in conjunction with some of the older florists, produced a charming variety of colours and double forms.