Helpful Nurse Plants

Forest and Bird, Issue 39, 1 February 1936, Page 3

Helpful Nurse Plants

(By Capt. E. V. Sanderson).

For Establishing Plantations of “Natives”,

The neglect to utilise nurse plants, in endeavours to establish plantations of native trees, is in constant evidence, with the- result that grass takes possession of the ground around the young plants. The growth is thus seriously retarded because air and moisture are excluded from the soil. On the other hand continuous cultivation for the checking of grass involves much unnecessary expense and work. ' In Auckland one sees attempts at native tree plantations where the plants are struggling for an existence against grass which is frequently cut or mown. In Wellington quite an extensive attempt was made with the help of unemployed labour to extend a native bush area. All the broom, in itself an already established nurse plant, was hacked down and burnt. The result was death for the planted “natives” which failed to survive last season’s dry summer.

A Blunder in Dunedin.

From Dunedin reports reach the Forest and Bird Protection Society of the cleaning out of all underscrub in some native reserves with the intention of producing that park-like appearance so dear to the English-trained horticulturist. In such instances the very training of an English horticulturist is against him in his endeavours to realise New Zealand forest requirements. The natural characteristics are thus destroyed, and the standing trees are robbed of their necessary floor protection. Moreover, the charm and uniqueness disappear, and little remains to interest or to attract visitors (especially those from other countries).

The area merely stands as one more example of that desire which has been so disastrous to New Zealand—the attempts to make this country merely an imitation of England or other lands. The fault, however, is not to be so much ascribed to the horticulturist as to those who ask him to undertake work which is not in his understanding. Give

him something more on the lines of a Dutch or English garden and he will excel.

Preferably Nitrogenous Nurses.

Now as to these nurse plants ! Having spaced the natives, which are to be permanent, sufficiently far apart to allow reasonable crown development later on, interplant as closely as you like with nurse plants (preferably a nitrogenous kind). Many quick-growing native plants can be used, such as lace bark, mahoe and others. Exotics, such as common broom and another broom (the gacia), tree lucerne or even gorse, make excellent nurse plants.

After the first season the nurse plants will overcome grass or other stronggrowing competitors, and all that is then required is the cutting back and later the thinning out of the nurse plants as they threaten to over-grow the permanent natives, until in a few years there is a native plantation only, all the nurse plants having been removed.

Refutation? of a Fallacy.

In this manner, following Nature’s methods, all the plants grow up together, each sheltering the others from wind and the soil from excessive heat and dryness. If nurse plants are thus used, the natives, if suitable to the locality, will grow fast with most species. It is, the writer thinks, because native trees have been seen to make slow progress in grassbound soil conditions that it has become the fashion to say natives are slow growers. The Mayor of one Auckland suburb enthusiastically stated that a native plantation he advocated would be a native forest in twenty years. The hoped-for result would be obtainable in five or seven years with the aid of nurse plants which would also save much labour, expense and loss of plants. This method of utilising nurse plants is merely an adaptation of forest practice in countries where scientific forestry is in evidence.

Nature’s Way at Tarawera.

It is also the method followed by Nature in establishing forest on perfectly bare ground. For instance, on the new soil formed by the Tarawera eruption in

1886, by which was deposited to a depth of several feet scoria, gravel, stones, sand, silt and clay on the top of existing vegetation —forest and shrubbery—it was not trees and shrubs that grew first but an organic matter or humus providing nurse crops of mat plants (Raoulia

sp.) the seed of which is carried by air like dandelion seed.

In the patch plants, which resemble a mossy growth less than an inch in height but yards in diameter, birds left the seed of the tutu

| (Coriaria), one of the best ‘ of nurse crops for woody growth but unfortunately poisonous to cattle. Fol- : lowing this shrub, which : dies out in about twelve ! years, the wineberry or | makamako (Aristotclia ! racemosa) with other ' shrubs such as tree ; fuchsia (Fuchsia excortiI cata), manuka (Leptospermum) and mahoe (Melicytus ramiflorus) how took possession of the mountain side.

If thus, on a soil lacking all organic matter and consisting of erupted fine and coarse rock, forest may be established by natural means, it must be easy to establish New Zealand forest on good soil. , ■