Work in the Garden

Lake County Mail, Issue 46, 21 April 1948, Page 7

Work in the Garden

BRILLIANT AUTUMN FOLIAGE When discussing autumn-flowering subjects recently, mention was made of several which also have attractive autumn foliage. To these we will add a few more from a large number of colourful specimens.

The change in the colour of leaves from green to the various tints of red, yellow, purple, and brown is due to changes in their composition. This is brought about mainly by sunlight and cooler temperatures. There are many external factors which influence the brilliance and duration of the display. The plants themselves, coming as they do from a wide range of climatic conditions, react differently to the seasons. The most successful seasons are those in which the plant makes good growth during the early part, followed by a hot summer and a mild autumn. Whilst freedom from hard frosts and strong winds will give a greater concentration of colour over a longer period, yet after even the most inclement of seasons there is always a good deal of colour. Too dry seasons, without moderate autumn rains, may reduce the display on lighter soils, while that on deep mois-ture-retentive soils may almost reach perfection. Drought may cause the leaves to fall early or mature prematurely.

It is important, then, to select plants suited to the soil in which they are to be grown. For the deep moisture-re tentiye soils we have some fine large trees in Liriodendron tulipifera (the “ Tulip tree ”), which bears large cupshaped flowers, cream-coloured with a bright orange throat # in early summer. The leaves are saddle-shaped, fresh green in the spring and beautifully clear yellow in the autumn. It makes a magnificent specimen, but does not like exposure to strong winds. Liquidambar styraciflua (Liquidambar) and Quercus coecinea (scarlet oak) are better known and rather smaller, though they will ultimately make large trees.

Some Choice Specimens It is rather difficult to name any one tree as being the best, but if I were forced to name my choice for autumn foliage it would be Nyssa sylvatica (the “ Tupelo ”), which is native to sAvamp lands of Eastern North America. Unfortunately, this plant is practically unobtainable at the present time. It does well 'in a loamy soil and colours scarlet and yelloAV. Pistacia chinensis may be considered equal to the “ Tupelo,” but it also, unfortunately, is scajee.

Ginkgo biloba (the “ maidenhair tree ”) turns a beautiful golden yejlow. The leaves resemble the leaflets of the maidenhair fern and there’s character in every branch. Strange as it may seem, it is allied to the fir trees. It is the only living member of a family represented in fossil remains reaching back 150 million years. The maples are Avell known for the fine foliage of Acer palmatum (“ the Japanese maple ”) and a fetv of the other species. Actually it is rather a large genus, found in its various species throughout the three northern continents. Most of them are deciduous and, though few have attractive flotvers, they arc excellent foliage plants. Small Shrubs for Good Soils /Of the smaller subjects for good soils, I Avould commend Disanthus cercidifolius, Bft to 10ft with roundish foliage like the Judas tree (Cercis), and Enkianthus, 4ft to Bft. There are

By J. W. Goodwin, N.D.H., N.Z., F.R.H.S., Massey Agricultural College.

several species, all with good autumn foliage and attractive flowers in the spring. Yaccinium corymbosum, 4ft to 6ft, is somewhat similar in flower, but distinct in leaf and form. Most notable of all are the deciduous Azaleas, which flower before the leaves show in the spring and colour brilliantly in the autumn. The mollis section and hybrids are best known and need no further recommendation. I have had an inquiry concerning Cornus florida. This and its variety \ rubra may grow from 10ft to 20ft in height and they prefer a good soil. Established plants have a distinctive form and the large flower-like bracts borne in November are very showy, white in the type and rosy red -in the variety. The autumn foliage of red and crimson shades is first-class. C. nuttallii is unfortunately not very well known and is also in short supply at present. This really fine tree often attains 50ft in height, the white flower bracts often Gin across, and the scarlet and yellow autumn foliage is said to “light up” its North American forest home.

Climbing plants which contribute to the autumn foliage effects are the Virginian creepers. They climb by tendrils which have small round viscous discs at the end, and are generaly sold under the- names Vitis or Ampelopsis. These discs enable them to cling to stone on concrete Avails. Inconstans and Veitchii are the best for this purpose. V. quinquefolia (the true Virginia creeper) is best over old stumps or the pergola. For Lighter Ground Of autumn-foliage plants Avhich do Avell in lighter and drier soils, Gleditchia triacanthos makes a large tree, the branches of which are spiny and the foliage is pinnate, that is, the leaf comprises a central axis Avith numerous leaflets on either side. The foliage and form are handsome and the autumn colouring is good.

A genus Avhich contributes a number of excellent subjects to this section is the Rhus or Sumach. Unfortunately,

some of them are poisonous, particularly if handled with perspiring hands. E. succedanea is the “ wax-tree ” of the Japanese, who use the wax or tallow obtained from the seeds. It will grow eventually 20ft to 30ft in height. Eather taller is E. verniceflua, the varnish or lacquer tree which supplies the lacquer used by the Chinese and Japanese for highly-polished woodenware. This tree is poisonous and must be used with care. Two really dangerous species which have been planted are E. vernix ,the poison Sumach, and E. toxicadendron, a half-climbing shrub known as “ Poison Ivy ” or “ Poison Oak.” I mention these as a warning of the types not to select. Pyrus trilobata is an upright-growing tree which usually makes a good show, whilst P. discolour is also really excellent for lighter soils. It is allied to the Eowan tree and has white berries tinted pink. Both grow about 12ft or 15ft in height. Enonymous (the Spindle Berry), well known for it berries, Amelanchier canadensis, a large bushy shrub with white flowers in the spring, and the more upright Viburnum opulus, all provide good autumn displays and grow about 10ft or 12ft high.

Most autumn-foliage plants prefer sunny positions, but should be sheltered from damaging winds if they are to show their true colours before the wind disperses the leaves.