SHELTER BELTS

Hauraki Plains Gazette, Volume 58, Issue 4108, 4 March 1949, Page 7

SHELTER BELTS

TREES ALONG DRAINS OPINION FROM PAEROA REDUCES SUCCULENT GROWTH The opinion that the growth of shelter belts of trees along the sides of drains was a highly commendable practice was given by Mr H. I*. Wylde of I’aeroa in a letter to the Hauraki Catchment Board. From his observations made in the low areas of th? Bay of Plenty and Poverty Bay and the high country of southern Hawkes Bay and local distlicts, he considered that where primary consideration had been given to the aspect of diainage and not solely to the creation of shelter belts, the effect of shading not only reduced the amount of succulent growth in the drains but by the creation of a cool draught, a strong deterrent was offered to blackberry, rose, honeysuckle and other objectionable creepers. “It is essential that the planting be done..on the most northerly side or where the drain runs in a north to north east direction then on the east side,” stated the letter. “ Th? reason for this being that all growth is more rapid in the early morning.

“ In the case of a north-south drain smaller than would normally be cleaned by a' dragline dredge, a hedge (barberry in the Bay of Plenty) on the east side trimmed at about three year intervals, caused very little loss of pasture, this was supported on the west side by deuduous trees spaced four or five to a chain, again allowing stock to graze up to the edge of the drain while taking advantage of the shelter.

“ The only maintenance this drain required was some cleaning out of ledves which was done at the time when farm work was most slack. The small amount of grass which lined the top edge was left undisturbed. “ The choice of variety must be based on rooting habit and ability to stand against wind, suitability to locality and type of soil 'and compatibility, when a combination is being considered.

“ Amongst those proved to be useful are the cupressus benthami macrocarpa and lawsoniana, gums and some deciduous exotic preferably supported by 'barberry on the drain edge, black acasia and when aesthetic value is to be considered matipo or hoheria are fast enough growing to provide the necessary “foot” cover for other natives. Bamboo along deep, narrow drains must be fenced against stock which will effectively prevent undue spreading into pasture. “ The quantity of needles shed by exotic nines .makes more frequent cleaning necessary. “ Gums in particular cast their branches which fail to grow. out to the light and in a plantation or line so many of dhese fall that trouble is caused, particularly at floodgates'.

“ It is not to be expected that maintenance can be neglected altogether but it is apparent that where a drain is effectively shaded the maintenance is so reduced that frequently it is totally neglected, until that time when cleaning becomes a major job. At this stage the trees are condemned because they prevent the approach of any .machine. ■ “ Maintenance should include necessary trimming of the trees and particularly the complete removal of dead trees or branches. “ In the case of a wide drain or canal where machine cleaning is essential, tall growing trees should be planted far enough back to be out of the way of the machine and where a diain is to be located on a road or other reserve every endeavour should be made to keep it oh the northerly side. “ The principal cause of trouble and adverse criticism of tree planting has been the planting or allowing to grow and to spread of the wrong varieties of trees.” the letter concluded.