HORTICULTURAL NOTES.

Otago Witness, Issue 3148, 15 July 1914, Page 12

HORTICULTURAL NOTES.

By J„ Gebbie.

HYDRANGEA PANICULATA. This hardy Japanese species is a very showy shrub of more than ordinary value in gardens, as it blooms during February and March, which are dull months, with flowering shrubs. Good cultivation and fairly hard annual pruning are necessary to obtain the best results, as, when allowed to grow naturally, the panicles of bloom are much smaller, although more numerous. To obtain large panicles Ift in length and bin to 9in through fairly hard pruning is necessary in August or September. Thinning of the young shoots must also be practised,, leaving only six to 10 shoots to mature according to the size of the , plant. The colour of the flowers is creamy white. The variety H. grandiflora produces larger spikes of bloom, and come into bloom about a month earlier than the other. Hydrangeas delight in a well-worked rich loamy soil with a mulching of good manure applied in December. ROBINIAS. The robinias axe all natives of North America, the five species in cultivation being either trees or shrubs belonging to the order Leguminosa. They are very attractive when in flower, and the nume-rously-divided leaves render the trees ornamental at other seasons. Robinia hispda forms, a beautiful bush, growing 6ft or more in height, with • forn-like foliage. The branches are clothed with stiff, bristly hairs, reddish brown in colour; hence the name R. hispida. The rose-coloured flowers are freely produced in pendent racemes similar to laburnum. As the habit is rather straggling, it is necessary to give it a little attention in the way of pinch in" and pruning when in a small state. Under cultivation it does not produce mature seeds, and even in its wild state good seeds are rarely, if ever, found. It throws up suckers freely, and is easily propagated from these. It is also grafted on another species. The year 1758 is given as the date of its introduction into England. Robinia pscudoacacia (the false acacia or common locust tree) is the best known, and forms a tree from 50ft to 70ft or more high, and is a fine tree for parks, gardens, and is also suitable for street planting. The timber is noted for its hardness and durability. The elegant fern-like foliage is very attractive. About December the trees nroduce large' quantities of white flowers in racemes, and these are sweet-scented. Something like 40 varieties or sports from the type are in cultivation, and have been given distinctive names, but few have as yet been introduced into this Dominion. PRUNING FILBERT AND -COB NUTS. The most important item of work in connection with the successful culture of nut trees "is the intelligent and timely pruning of the trees. It is for this reason chiefly that the Kent growers of nut trees are so far-famed. With them hard and seasonable pruning is the rule. The principle of nut-tree pruning consists of shortening the loading shoots of the previous season’s growth at' the end of the main branches bv one-third of their length. All the young sboots of last season’s growth which grow out of the main branches should be cut back to within three buds of their base of the cut shoots, from which, in due time, fruit will be produced. It must be borne in mind not to dostrov or injure the male blossoms until the fruit-buds have _ flowered and set their fruit, as good fruit is dependent on the pollen of the male flowers coming in contact with the stigma of the female bloom. It will help fertilisation to take place better if the trees are gently shaken on a dry, warm, day in order to

liberate and distribute the pollen most effectively. CHOICE FLOWERING SHRUBS. There are now so many shrubs available for garden decoration that those who have little knowledge on the subject experience a difficulty in making up their minds which to choose. • The following list of 12 are good, and showy kinds, which should find a place in .every collection:—.Spiraea arguta, an early spring-flowering shrub which, during October, is covered with a profusion of pure white blossoms. In ordinary garden soil it will grow to a height of 4ft, with a wide spread. The branchlets are slender, and have a -graceful appearance. It is only necessary to prune when the branches are outgrowing their allotted space. The branches should then be cut back as the flowers begin to fade. Diervilla Eva Rathkd is one of the most beautiful forms of this genus. Its rich crimson flowers are borne freely during the greater part of the summer. It likes a rich, loamy soil, and a little of the older wood should be cut out each year, allowing the young shoots to remain their full length. The white-flower-ing Diervilla is a good companion to the above. Viburnum plicatum is a most beautiful hardy shrub, producing during December or January a mass of round flowerheads, the flowers being sterile and made up of large white bracts after the manner of the common snowball tree. It is a native of China, grows 3ft or 4ft high, and requires no pruning. A light and sunny position is desirable. Viburnum tinus, the lauristinus, especially the variety lucidun, with • its shining green foliage and masses of pure white flowers, is well known. It transplants best when young, and requires no special pruning. Cyticus andreanus, a variety of the commbn broom, may bo grown almost anywhere even in comparatively poor soil. The flowers are yellow and crimson, appearing ;n profusion during November. Pruning must be practised each year as soon as the flowers begin to fade, but the branches must not be cut back into, wood which is older than one year. Forsythia suspensa, a native of China, forms a rather loose, graceful shrub, and bears a profusion of golden bell-shaped flowers during October. Its character is altered according to the way in which it is .grown. If allowed to grow freely its main branches support themselves on any object reach, and the other branches hang in a graceful -fashion round about. When planted in the open border and cut bard back to within 2ft of ,the soil each year- after flowering, it forms strong erect shoots 3ft to - 4ft long, which blosom from base to summit. Pyrus japonioa is a good hardy flowering’ shrub which comes early Into bloom, .the scarlet flowers being very showy. The double-flowering cherries, of which there are several varieties, are all handsome spring-flowering small trees, producing immense quantities of white or pink blossoms, and are anions' the earliest of spring-flowering trees. The various forms of double plums are also beautiful plants which are always greatly admired when in bloom. Magnolia conspicua is another magnificent flowering shrub, producing in the greatest profusion Large white blooms, with a purplish tinge on the back of the flowers. The crab apples (Pyrus malus florabunda, which produces large clusters of pure-white flowers, the outside of the petals being pink, followed by b r >>ht golden yellow fruit in autumn) and P. m. florabunda atro-pur-purna (with rich, rosy-red flowers) are very striking when in bloom. These are but a few of the good spring-flowering plants available; .to enumerate all would take too much space in the note.