GROWTH RATE OF NATIVE TREES UNDER CULTIVATION

Forest and Bird, Issue 56, 1 May 1940, Page 8

GROWTH RATE OF NATIVE TREES UNDER CULTIVATION

(By L. W. McCaskill.)

ONE of the complaints made against the use of native trees for planting for purposes of ornament, conservation or timber is their alleged slow rate of growth as compared with exotics. Although there is plenty of experience to the contrary there do not seem to be available many actual growth records of trees of known age. It is fortunate that we have in Canterbury such an enthusiast as Mr. J. M. Baxter of the Tawhai Nursery and Native Reserve on the slopes of Mt. Pleasant, near Christchurch. Mr. Baxter has spent several years in a labour of love—the changing of a dry grassy hillside into an area of artificial native hush, nearly three acres in extent. The result is what must be one of the finest collections of native trees and shrubs in existence. Of particular interest is the fact that the owner has personally grown from seed, cuttings, or wild plants, every plant in the

collection except those necessarily imported from the North Island. Further than that, he himself planted every tree and shrub, with the result that accurate information is available as to the age and soil treatment of almost every plant in the collection. The first trees were planted some thirteen years ago in holes prepared in the grass covering on the hillside. With subsequent plantings greater attention was paid to prior cultivation with results obvious from a study of the tables. In February, in company with Mr. Baxter, I made measurements of the height and circumference at ground level of representative specimens of trees and shrubs, together with the date of planting and the soil treatment prior to planting. Most of the plants would be two to three years old at planting and were planted out of pots or as balled plants from nursery rows.

A.—Planted in holes prepared in the grass. B.—Planted in well cultivated ground. C. — Planted in ground grubbed and trenched two feet six inches deep. Number of _ Height in Circumference Years since Species. Common Name. feet. at ground Planting. level (inches). 12 Nothofagus solandri Black beech 24-]- 19 12 Edwardsia microphylla Kowhai 18 13 | 11 Nothofagus fusca Red beech 16 26} II Pomaderris apetala Tainui 17 17 ' 8 Pseudopanax ferox Lancewood 12 6] 8 P. lessonii Lancewood 11]8 Nothofagus cliffortioides Mountain beech 21 12 8 N. fusca Red beech 15] 12 8 N. menziesii Silver beech 17 11 8 Podocarpus spicatus Matai or black pine 9 8 P. dacrydioides Kahikatea or white pine 13 10 8 P. totara Totara 18 15 8 Pittosporum ralphii 18 22 8 Griselinia littoralis Broadleaf or kapuka 12 11 8 Edwardsia te trap ter a Kowhai 13 8 Dodonea viscosa Akeake 19 16 8 Pittosporum eugenioides Tarata or lemonwood 19 16 13 \ 8 Hoheria populnea Ribbonwood 23 28 ** l 7 Nothofagus xblairii Hybrid beech 25 16 7 Fuchsia excorticata Kotukutuku 14 12 7 Phyllocladus trichomanoides Tanekaha or celery pine 9 6 Alectryon excelsum Titiki 11]- 2 6 Pennantia corymbosa Kaikomako 8 6 Cordyline australis Cabbage tree 17 33 6 Libocedrus bidwillii Pahautea or cedar 6 6 5 Pseudopanax trifoliolatum Lancewood 8 4 Edwardsia tetraptera Kowhai 11]4 Nothopanax arbor eum Whauwhaupaku or fivefinger 11 11 4 Griselinia littoralis Kapuka or broadleaf 11 4 Pittosporum ralphii 12 8 4 P. tenuifolium Kohuhu 14 11 4 P. crassifolium Karo 10 9 ' 2 Nothofagus cliff ortioides Mountain beech 7 4 2 N. fusca Red beech 9 5 2 N. solandri Black beech 10 5 2 Hoheria populnea Ribbonwood 12] 9 2 Nothopanax colensoi Orihau 9 5 2 Pittosporum ralphii 8} 2 P. eugenioides Tarata or lemonwood 7 4 2 Leptospermum scoparium Manuka 7 2 Edwardsia tetraptera Kowhai 6} 3 | 2 Dodonea viscosa Akeake 10 5 2 Aristotelia serrata Makomako or wineberry 8] 2 Cordyline indivisa Cabbage tree 10} 21 2 Libocedrus doniana Kawaka or cedar 4 2 Br achy glottis rangiora Rangiora 7 2 Agathis australis Kauri 4 2 Entelea arborescens Whau or corkwood 6 2 Laurelia novae-zelandiae Pukatea 4 l 2 Vitex lucens Puriri 4

These figures are eloquent proof of the rapid growth of native trees under dry conditions with light winter frosts. The main factors necessary appear to be thorough preparation of the soil, use of hardy nursery-raised stock, and planting in close association. Mr. Baxter’s garden is an excellent example of the results of planting “bird food” and sup-

plying fresh drinking water. Birds are with him all the year round feeding on nectar of kowhai, flax, and fuchsia, and the berries of poroporo, fuchsia, wineberry, cabbage tree, fivefinger, broadleaf, ngaio, and the pittosporums. Dozens of birds nest undisturbed every year.