THE GARDEN

Otago Daily Times, Issue 26963, 24 December 1948, Page 2

THE GARDEN

Contributed by D. TANNOCK. A.HJUU.

ANSWERS TO CORRESPONDENTS “ Rhododendron," Milton.—The withering of your rhododendron leaves round the margin and at the apex is usually an indication of lack of moisture at the roots. Examine them, and if dry give a good soaking, then mulch with very old cow manure and leaf-mould, or failing these, good clean sawdust. "Amateur,” MosgieL—l presume you mean tomatoes, though you do not say so. Spraying with Fullset when the flowers are fully developed will secure the formation of the fruit. It is usually the lower bunches which fail to set. C. F. H., Balclutha.—lt is probably exposure to the cold winds which is responsible for the brown parts of the leaves of your Garryia elliptica. You should shelter it from the cold south-west winds with some scrubby manuka until it becomes established. “ Grower," Roxburgh.—The malformed berries on your strawberries could be due to a touch of frost. There is a caterpillar on the foliage, and you should dust them with derris dust in the meantime, and. after the fruit is picked dust round the plants with a mixture of horticultural naphthaline, and twice its bulk of wood ashes, working it into the ground. Mildew has a powdery appearance, but I did not detect any on your plants. It is often due to dry conditions, and in the meantime watering may arrest the attack. Dusting with sulphur or White Island product is also recommended. HERBACEOUS PERENNIALS The herbaceous perennials are a very useful race of plants which are quite hardy under any of our conditions and which die down in the autumn to a rootstock. bulb, tuber, or tuberous roots, or young growth, which spring up round the base of the old flower stems. The herbaceous or mixed border, when planted with a representative collection of hardy plants, is ornamental and interesting practically all the year round, and the maintainance is not great. However, though : the plants are perennial, and spring up In the spring, flowering mainly during the summer . and autumn, they must receive ..a certain amount of attention to get the best results. For example, the spreaders like Michaelmas daisies, heleniums and perennial phlox soon become overcrowded, and should be lifted and divided up every year or at the least every two years, young pieces of the clump from the outside being selected for replanting. A still better method, which can be applied to delphiniums as well, is to take cuttings of the young growths, when about four to six inches in length, and put them into a shaded sandy bed in the open or a sandy bed in a cold frame. They soon root, when they can be lined out in nursery rows on a well-manured border, where they will make nice young shapely plants fit to plant out In the autumn or spring. Paeonies, Oriental popples and hellebores are the exception. When doing well these should not be disturbed on any account. There are a number of plants which do not throw up young growth round the base of the flower stem suitablfe to make into cuttings. Those which have ffeshy roots like Oriental poppies, Ervngium, Phlox, Statice c. can be grown from root cuttings. Others, like carnations and plants of a trailing type, are easily propagated by layering. Many are true species, and the improved varieties of several others can be raised from seed. This is better sown as soon as ripe and though it may not germinate until the spring it will be quite safe during the winter if covered with some pieces of twiggy scrub. Young plants raised from seed are usually more vigorous than those propagated in a vegetative way, the hollyhock being a good example. Plants raised from seed are far less liable to attacks of rust on the leaves than those grown from cuttings. The maintenance of the herbaceous border is not exacting; in fact, a wellarranged one should show little soil, and what there is should be hoed regularly. Some of the strong growers will require liquid manure occasionally. If the soil is light, a mulch of strawy manure, spent hops, cocoa shells and sawdust will help to retain the moisture in the soil. Staking is necessary, and this should be attended to at an early stage, three strong stakes being put in to support the very tall ones, such as the delphiniums, lupins and Michaelmas daisies. -Strings should be tied round them and across from stake to stake to prevent the stems from being blown over to ,one side. The medium growers and the dwarf kinds can be supported by means of twiggy branches, which are stuck in and around the group, so that the flowering shoots can grow up through them. It is also important to cut away the old flower stems as soon as they are past their best, but not to cut lower than the flowers, for a certain amount of foliage is necessary to build up the plant in preparation for next season’s flowering. MAJOR VARIETIES

There is a long list of herbaceous perennials, but I will only mention some of the largest and most important groups. I could not do . better than start with the delphiniums.. These have been greatly improved during recent years, and there is now a marvellous range of- glorious shadings and markings of the flowers. The remarkable formation of the centre reminds one of the tiny humming birds or bees as they flutter to and fro among the pale and dark blue flowers and green foliage. In addition to the vast range of shades, there' are single, semi-double and double flowers on the tall, stout, wellbranched stems. If the dead spikes are cut immediately after flowering, a very presentable show can be obtained in the autumn. The ever-blooming Belladonna section should also be represented in the border. They have a free-branching habit and persistent flowering qualities in succession, until destroyed by early frost. Pink Sensation is a distinct break in delphiniums, the flowers being a salmon rose without any blue or purple. It belongs to the Belladonna section. D. nudicaule is a dwarf species for the front of the border, colour brilliant scarlet.

Perennial asters (Michaelmas daisies). This is also a large and varied group, there being varieties from 6in to sft tall, representing many shades of blue, pink, etc. Of the Amellis section, King George is the best; of the Novas-angllae, Barr’s Pink, Lil. Fardell and Mrs S. T. VSfright; of Novae-Belgi, which is the largest group, there is a great variety, including Anets Ballard. Cloudy Blue, Margaret Ballard, Perry’s White, Queen of Colwell and Royal Blue.

I have already dealt with the various species, hybrids and varieties of the Iris, so there is no need to do more than mention them now. Phlox decussata, the perennial phlox is also a large group most valuable in late summer and autumn. The colours are so bright, varied and attractive, and the habit of the plants is dwarf and very suitable for massing. Many of the old purple varieties have been discarded in favour Of the pink, salmon, salmon-pink and orange-scarlet varieties.

Paeonis sinensis, Herbaceous Pseonies. These magnificent perennials need no praise, and are especially attractive when established and luxuriating in by themselves or mixed with the other her-i baceous plants. The best results are obtained by planting in deeply-trenched ground with a liberal supply of rotted manure, either In the soil or as a mulch. They resent being disturbed, and when doing well should be left alone. Other good plants for the herbaceous border are the Oriental poppies, Heleniums, gypsophila (Bristol Fairy), anemone .japonica, salvia patens, pyrethrums, rudbeckias. pentstemons. Primula species, Monardae didyma, kniphofias, alstromerias, gaillardias, gazania, astllbes, spiraeas, anthemis, aquilegias, and, of course, the various lilies.