HORTICULTURE.

New Zealand Journal of Agriculture, Volume 54, Issue 4, 20 April 1937, Page 249

HORTICULTURE.

The Planting Season.

The months of May to September inclusive are known as “ the planting season ” period during which hard-wooded plants may be set out to best advantage : hedge-plants, shelter-belts, ’ fruit-trees, bushes, and ornamental shrubs. Where the requirements have been carefully studied and planned and the land thoroughly prepared, the work is best done without delay when the ground is free from frost and not too wet. Considerable root-growth is made during the winter, which greatly facilitates establishment. Only in cold exposed conditions is there any advantage in delaying the planting of less hardy plants until the end of the planting-season. It is best to take delivery of plants of this class so soon as they are ready, and heel them in in a piece of friable, ground. They will then be quite secure for the whole of the planting season, if necessary, and may be planted out as weather conditions and other circumstances permit.

Advice on planting is often somewhat laboured, but if the plants are suited to the conditions of soil and climate and the ground has been prepared as advised it is only necessary to observe a few precautions. Straggling and damaged roots should be pruned back, and the plant set in a hole sufficiently big to accommodate the roots without crowding and of a depth which will allow the plant to be set at the same level as in the nursery. In filling, the soil should be broken fine and distributed evenly, and when the roots are covered it should be trodden thoroughly firm, and the filling then completed. . Loose planting is the commonest and most serious fault. Plants with a long stem, such as standard roses, &c., require staking. For these a hardwood stake of suitable length should be driven when the hole is opened ; the plant is then 'firmly planted beside it and made secure by tying it to the stake with strong tarred string. A piece of canvas or other material round the stem of the tree under the tie will prevent it from injuring the bark.

Plants which have had their roots considerably shortened when lifting in the nursery will require to be pruned. This operation will require careful consideration — than it usually receives. Those which make young growth subject to damage by frost, such as roses, are pruned only lightly when planting, the pruning being completed just before, or shortly after, growth commences in the springat the later period in the colder districts. Shrubs having more than one stem, or which branch low down, should have the branches thinned to three or four well-distributed growths so that crowding will not take place as they get older. They should be removed completely, close up to the point of origin, cutting them off flush. The remaining growths should then be shortened, cutting just beyond a good bud pointing in an outward direction. The plant will then.make well-spaced bushy growth. Plants which it is desired to grow on a main central stem, pyramid fashion, should have any vigorous growth likely to compete with the central leader removed completely. Many specimens that are otherwise admirable have this double leader, which is not only disfiguring by spoiling the balance of the tree but frequently causes serious injury. The remaining branches may then be thinned out where there is any sign of crowding, and

the leader and branches left should then be shortened moderately. By careful training in this manner young plants not only make vigorous growth but also shapely trees, which'will best attain the main object, whether it be shelter or any other purpose. Plants with fine roots, such as heaths, rhododendrons, and most conifers, require little or no pruning when planting but. • To enable them to make satisfactory growth, most plants require light and air, as well as the soil and water in which they are planted. For this reason grass and weeds should be suppressed when they make their appearance in the vicinity of young trees. Clean culture is most desirable, at least for a few years until the plants are thoroughly established and cease to be in danger of being overgrown by such wild growth. In the case of hedge-plants such growth should never be allowed to attain any considerable height close to the base of the hedge, or much of the foliage there will be destroyed ; this will cause great disfigurement as well as reduce the efficiency of the hedge. It is a disfigurement which it is very difficult to adjust. In the case of plantation-trees, spot-planted in grass, the grass should be mown at least once a year, about the month of December before it seeds ; it can then be allowed to lie as a mulch, where it quickly decays, and among other useful purposes assists in retaining moisture, especially during the summer months, when young plants are inclined to suffer from: a shortage. Breaking in Grass Land for Cropping. Land suitable for intensive cropping is a good deep loam on a welldrained subsoil ; such soil usually carries a heavy turf, which is best broken in with some care, especially when infested with couch-grass or any other bad weed. In such extreme cases cultivation should be commenced in summer, when the land should be fallowed and cleaned during the dry weather, as has been previously recommended. In an opposite extreme case where the turf is thin and free from serious weeds, ploughing and subsoiling may proceed in the usual way ; but where the turf is heavier it usually is best to skim-plough now, and some weeks later when the grass is dead cross-plough, burying the turf deeply, and at the same time using a subsoiling attachment, or a second plough, to break up the bottom of the furrow. On a new site, water-supply, drainage, and wind-shelter will each require consideration. The difficulties which arise are very frequently due - to inadequate attention being given to one or the other of these fundamental requirements. Land suitable for early crops— is, land with rather sharp drainage and consistently warm temperatures — most likely to require a well-arranged irrigation system. Fortunately, in most cases of this kind artesian water is easily available, and sprinkler, irrigation. can be arranged which uses the water with economy and best effect. Apparatus of this class has been much improved during the last few years ; sprinklers with wide coverage, even distribution, and instantaneous couplings, for sections where movable piping is used, are now available. Drainage is of greatest importance where the land is heavy, especially where water is received from adjacent higher ground. During the busy periods in autumn and spring it is difficult to “ catch ” this land in suitable condition for working unless ample drainage is provided. Where the frequent cultivation necessary to intensive cropping has to be done, drainage improvement is essential. On new sites shelter from prevailing winds is often deficient for horticultural crops; in most localities an ample provision of intersecting hedges is required. These should be planted now and given all the attention due to their importance. Vegetable Crops.

The growth on asparagus crops should now be mown, raked, and burnt ; the land should be lightly disked, and a low ridge should be thrown up over the stubble to rot it. Special attention should be given

to land being prepared for planting out permanent crops such as asparagus and rhubarb. It should be clean, rich, and deeply worked ; a good dressing of kainit for the asparagus and superphosphate for the rhubarb should be included. When the foliage has died down on rhubarb that is to be replanted, spare roots may be lifted and forced in a dark shed maintained at a temperature of 55 0 F. to 65° F. Place the roots close together with a little light soil between and maintain a humid atmosphere by means of tepid water. ■ In frost-free localities peas and potatoes are planted now for harvesting in early spring. For this purpose a variety of main-crop pea is chosen ; a good strain of Stratagem is popular. Small and Sundry Fruits, &e. The unusually high price of shelled sweet almonds at the present time has drawn attention to the production of these and other nuts. From the little experience we have had of almond-growing in the Dominion the indications are that they thrive best in the drier districts where late spring frosts are not severe. Isolated . trees are usually barren, as they are generally self-sterile, and to obtain a crop at least two varieties must be planted. The soft-shell varieties are preferable, such as 1.X.L., Ne Plus Ultra, and Hatch’s Nonpareil. These are also suitable for crosspollination, which will be most effective if bees are kept in the vicinity. An average crop is 5 lb. or 6 Ib. of nuts per tree but twice that weight may be obtained from the above-mentioned varieties under good conditions. The kernels weigh rather more than half the weight of the nuts. Bordeaux sprays in spring and autumn are required to control shot-hole and other fungi. A good soil that is light and well drained suits them best. ■ ' Sweet chestnuts {Castanea vesca, syn. Castanea saliva) are from the mountain forests of Southern Europe and Western Asia. They are handsome deciduous trees with useful timber. Baked or boiled the nuts make a , wholesome dish, and are usually popular where they are plentiful. There is ample evidence here that the trees will crop well on good warm hilly country. A group of these trees looks well and provides useful shade, as well as a crop of nuts. Like other nuts, when properly, cured, they have good keeping-qualities and may be used at any season. Filberts, hazels, and cob-nuts are popular names given to varieties of Corylus colurna and C. avellana. Our supplies haVe chiefly come from Spain, where these trees are grown extensively, especially in the Province of Tarragona. The most suitable soils there are said to be. light, cool, and deep, well aerated, and with a fair supply of moisture. Planting-distances there are 8 metres between rows, and 4 to 5 metres between trees in the row, say, 26 ft. between rows and 13 ft. between trees. In cool districts in the Dominion there a few groves planted, and they are cropping well. There appears to be no reason why they should not be extended. When planted in rich, moist soil the trees run to wood and are not profitable. Trees grown with an open centre, on a light well-drained loam, and the suckers suppressed, crop best. Fertilization of the “ flowers ” is by wind-blown pollen from catkins. For heavy cropping the question of pollination demands careful consideration, but until further variety tests have been carried out here mixed varieties should be planted. An average yield generally is about 1,000 lb. of nuts per acre.

Walnut-culture has been somewhat checked by the prevalence of bacterial blight, but trees vary widely in their susceptibility to this disease. The trouble also is less prevalent in the drier districts.

Selected trees planted in groups, or as single shade trees, or as an avenue, will often serve a useful purpose in addition to supplying a crop of nuts. They should be planted in good well-drained alluvial land in a district with a comparatively low rainfall. The Homestead Garden. The planting-season provides the necessary opportunity for planting up shelter-belts and shrubberies in the new garden. Distances between shrubs and trees are usually 3 ft. to 6 ft. or 10 ft., according to the adult size of the subject or the purpose in view. On the windward side a shrubbery at maturity should present to the eye a comparatively close wall of foliage of various shades and shapes; inside are taller trees with an undergrowth of shade-loving shrubs and ferns ; on the leeward margin the choicer shrubs and trees are placed, often in rather more open order, the more attractive features being set out in comparatively large' groups. While the plants are small and of a similar size, planting should be done with the greatest care to obtain the best effect, for as the plants mature and reveal their character any defects in arrangement will be revealed. The art is best acquired by studying the native bush and public and private gardens and plantations in the vicinity, and noting the results of the various arrangements under the local conditions of soil and climate. The established garden also usually receives great benefit from some consideration during the planting-season, for, as in the natural bush, there is no finality to the operations of sowing and reaping. With shade and shelter established, many climbers, ferns, palms, and shadeloving shrubs will find a congenial environment and grow away quickly with best results if planted now. And, as ripe pine and gum timber is removed for use, the vacant areas should be replanted where second growth is not expected. Not a garden has been planted but what improvement may now be made as a result of new experience which has been gained. In mild, moist western districts where rhododendron, azalea, camellia, hibiscus, hydrangea, palms, and tree-ferns flourish these should more usually provide the materials for some of the more outstanding features in the gardens. Most of the kinds of plants mentioned have a wide variety that provides for almost any effect which may be desired. In the drier atmosphere of eastern districts the rose, carnation, wattle, bignonia, bougainvillea, syringa, tamrix, magnolia, oleander, banksia, phoenix, and -palms are among those plants which readily make a good display under the conditions there: also most bulbs of African origin, and tubers and bulbs, such as irises, anemones, &c., from the Near East, if comparatively dry sites are chosen. The present season presents an opportunity of extending the more desirable, features in garden-planting in the place of those less suitable. In new gardens where the preparation of the land has not reached the planting-stage, the work should be continued when the land is sufficiently dry, with a view to sowing down lawns about the month of August and completing the planting of hard-wooded subjects by the end of September-especially in the drier localities.

—W. C. Hyde,

Horticulturist, Wellington.

Parasitic disease is responsible for considerable loss in young cattle. Many calves die or have their constitutions undermined by the action of internal parasites. In combating the trouble, the importance of the provision of extra nutritious feed in assisting the young animal to overcome the effects of the parasites cannot be overestimated. In this respect chaff, oats, and good hay will do far more good than drenching with worm medicine.— A nnual Report, Director, Live-stock Division.