GARDENING NOTES.

Otago Daily Times, Issue 17693, 2 August 1919, Page 3

GARDENING NOTES.

Bx D. Tannock.

WORK FOR THE WEEK. - a» • THE GREENHOUSE. Continue to pot and topdxess the warm I greenhouse plants and maintain as moist and growing an atmosphere as possible with the mrmimmtn amount of fire beat. Owing to the scarcity of cool it may be necessary to mafee up hotbeds inside to obtain suffioent heat for th e germinating of seeds, the starting of newly pricked out annuals, . newly potted up plants, and the rooting of ' cuttings. ' The method of preparing a hotbed was described in last week's notes. . Put in cattingß of lobelia and other tender bedding plants as they become available!. They will still be somewhat slow in rooting, but where a large stock is required it is neoessary to start early, ,and then the cuttings when rooted can be \ topped once or twice to : supply Liter batches. As soon, as the seeds of cabbage, cauliflower, antirrhinums, e to., which were sown a little while ago have germinated they ' should be shifted out into a cool house .and stood tip on a shelf near the glass to prevent them from becoming drawn and' spindly, and should they have beep sown too thick the seedlings can be thinfled out a little to prevent damping off. Greenhouse calceolarias and pelargoniums £ra very dirty plants ,and are usually harbouring some green fly under their leaves. They can .be fumigated with X L All, or syringed with soapy water, talking care' to force the soapy water up tinder the leaves and to wet the whole plant. THE FLO WEE. GARDEN. Continue to prune shrubbery to clip and dean out hedges, to trench, and form now beds and borders, and to repair and topdress lawns. Bulbs of various kinds are new peeping through the ground Mid advantage should be taken of all dry sonny -weather to weed and fork •I up the beds and borders in which they are growing. , Owing to the mild, dry -weather which ■we have experienced this winter, it has been quite possible to plant out .trees and shrubs at any time, but August is geiierally the most suitable month, and all pkmting and transplanting should be put in hand as* soon as 'posdble. Some trees, such as Primus pissaidi, begin growth very early; in fact, the buds are well" advanced already. . V Rhododendrons and azaleas are such useful garden plants and they thrive so well in the soils in and round Domed in that they ought to be represented in all gardens, no matter how small they are. As their requirements are different from the other trees and shrubs they grow best when planted in beds and borders by themselves where liberal _ supplies of leaf mould, peat' or other organic matter can be added to the soil where necessary, and where they can receive atf annual top-dressing of leaves or well-decayed stable manure. ' The most suitable soil is one overlying a clay subsoil, which when trenched and manured will retain moisture during the lummer End at the same time provide good drainage during the wet winter months. They do better and show to greater advantage when planted on a bank or the ■ides of a gnlly or dell, and though they do not objeflt to slight shade from deciduous trees do not . like to grow under evergreens, such as pines and other coniferae and object to strong rooting trees, such as elms and ash, which rob them of their supplies of food and moisture. It is understood that they do not like lime, and that they will not grow m limestone distriots; * also that it is a mistake to give them any manure such as basis slag which contains large quantities of' lime. Their roots do not wander into the subsoil like many other plants. They,form a.compact ball near tho surface, hence the reason for applying mulchings of leaves and manure, and also the explanation why they can be so easily and successfully transplanted even when they are very large plants. In their native home many rhododendrons are epiphyses. ' They therefore obtain their nourishment from water plus the little humus' which is contained' -in the debris which accumulates about their roots. In this respect th<jy resemble orohids, and though they like mulching with manure, it must be wfell rotted, and it is the humus which it contains which they like—not the usual manurial constituents for which it is valued by other crops. A soil which is light and gravelly or sandy is not naturally suitable, but it can be improved by the addition of clay, loam, peat, and other organic matter. The ponticums and the 'pontlcum hybrids and azaleas are not so exacting as to soil conditions as the himalayan kinds. They will thrive in any good loamy soil without any addition of peat or any annual topdressings provided it is well trenched and well drained. Though the ponticum rhododendron is not of • such a desirable colour as most of the hybrids it is such a useful and such a hardy plant for massing in groups in large parks, near hikes, or by the sides of rivers and for planting as an undergrowth for deciduals trees. The Himalayan kinds are really alpines, and though they require some shelter from the cold S.W. winds they must not be closed in too much.- I remember seeing a very choice collection in a garden in the north where to all appearances the conditions were idea, but they were covered with thrips and not at all healthy, and this was largely due to the stagnant atmosphere and probably too much moisture at the roots. When_ planting a rhododendron bed or ' border it is best to plant fairly close at first to obtain an immediate effect and to transplant later when the plants beg-in to crowd _ one another. They can be lifted so easily and transplanted with so little injury that the borders can be rearranged and extended later on. They can also be pruned bade if they become too tall and leggy, but as the buds are borne on the ends of the stems on the previous seaspn'a wood to cut them l>aek means the loss of the blooms for a year at least. Four to five feet apart is a suitable distance for a newly planted border, and later on by lifting every second plant they will be from eight to ten feet apart, which, is a very reasonable distance. The following are a few good Pontifjum Hybrids:—Alarm, centre white edged with j. scarlet, Caucasicum album, white, Donoaster brilliant Bcariet, Miohael Waterer, rosy scarlet, Mrs E. C. Stirling, blush pink, Pearl, largo pink, The Warrior, scarlet, Gomer Waterer, blush. List of Himalayan species and hybrids:— Aboreum (William Schilson), pink, Aucklandi, pearly white, Ciliatum, Bale rase (dwarf). Countess of Heddington), palo pink, Fragtr itifsirmrm, white, Gill's Triumph, ont; _ o the best, Kewense, rich rose, Nuttallii, creamy white, Princess Alice, blush white, Sniithii aureum, pale yellow. The six most suitable rhododendrons for a small collection are Gomer Waterer, Michael Waterer, Pink Pearl, Counted of Haddington, Aucklan4ii, Fragrantissinram, Tho deciduous azaleas (Azalea mollis* aro very beautiful m spring. When established they flower_ freely, and their colours arc distinct, which,, combined with their dwarf habit and hardiness, make them most desirable plants for both large and srhall gardens. . They thrive in well-drained loam, and do not require the annual topdressings which the rhododendrons need . Thoy cm be_ planted in beds by themselves or grouped in tho front of the rhododendron or shrubbery borders. The Indian azaleas are also hardy in some districts and are suitabo for filling beds or ing in front of the rhododendron bonier. They are also very satisfactory on rockeries. Azalea amoena, is a very hardy evergreen kind, lxit unfortunately its colour is not very good. The Javenese rhododendions aro very fine, but they are hardly hardy enoujjhj, and dg better ia tiaa-gmenJiousa,