Planting Farm Shelter in Northern Wairoa.

New Zealand Journal of Agriculture, Volume 56, Issue 5, 20 May 1938, Page 327

Planting Farm Shelter in Northern Wairoa.

E. H. Arnold,

Instructor in Agriculture, Fields Division.

IN the northern Wairoa district the planting season for farm shelter commences during the autumn after the rains have sufficiently moistened . the ground. The best results are obtained if the work is completed by the end .of May or early June. If the soil lies wet during the winter spring planting is necessary, and this should be completed by early September to enable the plants to be well rooted before the dry weather. The soils of the river-flats in this district range from peats to good river alluvial loams, and in some areas rather intractable clay silts are found. Careful preparation of the site of the future shelter-belt is necessary to obtain successful establishment. The best method, one that is seldom performed, is to plough and work up the proposed shelter-line. Excellent takes have been obtained by working up with the spade or mattock circular planting pits 18 in. to 2 ft. in diameter. . Care must be taken not to set the plants out in a saucer-shaped hole, into which water drains from the adjacent unworked soil — a practice which causes many failures in the district. After rain has fallen the water lies in the depression, the roots rot, and the shelter-trees die. Fencing is necessary for the successful establishment of most types of shelterplants, and any expenditure on this should be looked upon as part of the cost of providing shelter and not as an extra expense to be avoided or reduced. Fences are frequently erected too close to shelter rows, and fail to protect the young trees from stock. The trees become stunted or grow unshapely. Close-fencing Unwise. Close-fencing of established belts, particularly of the taller-growing trees, leads to the lower branches being destroyed, for the stems become bare, and the upper portion then develops heavy and overbranched side growth. The open conditions at the base allow draughts to drive through, and stock are better out in the open than near such belts. Shelter-belts have been established in the district for a sufficient period to decide which are the best kinds to grow. Many plantings have failed through attempts to grow the wrong variety or kind of tree. - Again, lack of success has

been caused " through poor planting methods and lack of attention after establishment. The following . notes deal with those shelter-plants which have proved their usefulness on the northern Wairoa flats. Cupressus Macrocarpa. This vigorous and rapid grower has been more extensively planted on the flat than any other shelter-tree. Under poor conditions of management it has developed into large, rough shelter, covering a good deal of ground, but bare at the base where shelter is most needed. With adequate protection from stock, systematic topping and trimming of the sides, macrocarpa provides many miles of excellent farm shelter. Where soil conditions are too wet for macrocarpa single plants die out, thus

spoiling the whole shelter row. This tree, although used . mostly as a single-row shelter, could be better utilized in mixed shelter-belts to act as the main breakwind if planted 6 ft. apart, either in single'rows or in mixed belts. It is a valuable tree for planting in compact blocks for timber purposes. ' , '

Cupressus Benthamii. On soils which hold the moisture unduly or where the water-level is fairly close to the —conditions such as are found on many areas of these flats— tree succeeds where macrocarpa does poorly. Although a certain amount of planting

has been done its use is not fully appreciated. Benthamii, particularly during its early life, will not tolerate the saltladen westerly winds ; if planted east and west only those few plants at the western end of the shelter row are affected. A single row of pampas planted 6 ft. away on the west side of the proposed line of Benthamii proves beneficial. The pampas grows rapidly, affording protection to the young trees, and later provides the dense bottom shelter while the trees give the higher protection. In such cases the fence may be placed closer to the base of the Benthamii, and the overhanging branches provide a certain amount of shade for stock. When Benthamii is planted in a single row fencing should be kept at least 6 ft. away from the base of the trees. Two-year-old trees spaced 6 ft. to 7 ft. apart give the best results for tall shelter, and they can be topped when they reach a height of 12 ft. to 15 ft. Cutting back every two or three years is then necessary. Pampas-grass. The second most popular shelter-plant grown is pampas-grass. During the flowering season in the autumn the lines of plumed pampas-grass give a picturesque note to many parts of the district. For dense low shelter up to 10 ft. high this plant is unsurpassed. Apart from maintaining adequate fencing at least 4 ft. to 5 ft. away from the base of the plants, no other attention is necessary. Trimming, the bugbear of hedges, is not required. ‘ When planted alongside the edge of a drain the roots assist in maintaining a firm bank. Sometimes the overhanging foliage reaches over the drain and shades the opposite bank, which is kept from crumbling during dry weather. In such cases the use of a sharp slasher is all that is necessary when the drain is cleaned. . ■

During seasons when winter or'early spring feed is short the fencing-wires may be removed temporarily and the stock allowed to graze on the pampas. By next winter the regrowth is sufficient to provide low shelter. Well-rooted sections of old plants or two-year-old seedlings, which can be obtained in many parts of the district, can be planted out 5 ft. to 6 ft. apart in single rows during August or early September. One-year-old seedlings, such as can be obtained from Whangarei, are best held in a nursery bed for twelve months. Put out about 12 in. apart, and then next season transplant in their permanent positions, making sure that a good ball of earth remains with the roots. Where tall breakwinds are being planted pampas-grass proves valuable in providing the low, dense shelter so necessary when the taller-growing trees open up at. the base. Pampas-grass planted out in the spring usually makes sufficient growth to protect young trees set out the following autumn. Acacia Verticulata (Prickly Acacia). Conditions are very favourable on the flats for this rapid-growing hedge plant, and many good hedges are to be found growing. Because of its prickly nature

it does not require fencing, except for a short period after planting. Good results are obtained by setting the plants out under the bottom wire of the fence-line. It does best if kept well trimmed after the second season’s growth, but many good hedgerows are only roughly cut back every few years. Seed can be sown along a narrow strip of prepared ground in September :or October. Plants, if used, should be set out 18 in. apart in a single row. Phormium tenax (New Zealand Flax). . Conditions are very suitable for the growth of flax, and it is rather surprising that use of it has not been made in this district for shelter-belts. Short rows are to be found, however, and in one instance clumps have been left in a field when the land was sown down to grass. As previously recorded in the Journal, flax is popular in Southland, where the plants are cut for milling purposes. During this autumn, belts are to be planted on the Northern Wairoa Demonstration and Experimental Farm. In time the rows will be cut for milling and 'valuable information will be available. Rooted fans from established plants can be set out in May or early June in single or double rows 5 ft. to 6 ft. apart.