TUBEROUS BEGONIAS

New Zealand Herald, Volume LXXI, Issue 21912, 22 September 1934, Page 8 (Supplement)

TUBEROUS BEGONIAS

UNRIVALLED FLOWERS For the decoration of tho greenhouse during tho summer months, tuberolis begonias aro unrivalled. The fact that they aro extensively used for summer bedding is an indication of their simple tastes. Some allowance, however, must always be made for the different conditions which prevail' under glass. High summer temperatures will create an extremely dry atmosphere. Begonias refuse to grow under such conditions, and once the leaves stop developing tho case is hopeless. To prevent anything in tho nature of excessive dryness, shading should be employed on the roof, and moist surroundings created for the plants by damping down the paths and stages daily in hot weather. If the pots aro stood on gravel or other moistureretaining material, the call for water will not be so frequent. If cool, moist, airy conditions are maintained throughout the summer, and the plants are neither over-potted nor over-watered, there is not the slightest fear them failing to produce blooms of the highest character. Propagating Named Varieties Named varieties can only be propagated by vegetative means, and to build up a collection of varieties it is necessary to purchase tubers. Although they have started into growth, there is still time to obtain these. With careful handling they should give a splendid display. The best of the modern seedling strains can also be relied on to yield some wonderful results. It is rather late to sow seed this season, but seedling plants, tho majority of which should flower freely in February and Mar<ji, can be purchased. With begonias more than with any other plant, it is essential to purchase only first-grade seed. The best strains are saved exclusively from lip-to-date collections of named varieties. Although seemingly expensive, consideration must be given to the fact that a large amount of greenhouse space and •«, great deal of careful work are required to produce a fraction of an ounce of seed from the double varieties. Suitable Compost

Begonias resent a continuously sodden soil, and over-potting is a serious error which must always be guarded against. A three or four-inch pot is quite largo enough for tho initial potting once the iubers have started into growth, and when these are nicely filled with roots a move can be made to five or six-inch size. For all except old tubers, these will be largo enough to carry the. plants to the end of tho season. Long before that time the contents of the pots are simply a mass of roots, and plants will derive much benefit from the application of' liquid manures and fertilisers.

A good soil mixture or compost suitable for begonias consists of three parts of fibrous loam, one part of welldecayed manure, one part of wood ashos and sufficient coarse sand to keep the mixture open. The whole should be passed through a one-inch sieve, dusted over with soot and bonemeal and turned over two or three times to ensure equal distribution of the ingredients. When potting let the crown of the tubers be level with the soil surfaco, and make the compost just firm over a good drainage. The delicate roots will never make headway in a tightlypacked soil. For tiny seedlings the soil will, of course, be sifted finer. It is best to prick these plants out in boxes, first, and pot up when they have attained some size.

For tho first week or two after potting water must.be used with discretion, in order to give the roots an opportunity of working in just moist soil. As a further aid to maintaining cool, moist conditions, tho foliage mav be Bprayed overhead in Warm weather. h urther cultural details are that all buds that show should bo picked off until tho plants aro in their flowering pots. If the soil is just moist at potting, no more water will be required until the pot rings when struck sharply with the handle of a knife or a piece of wood.

There are many varieties of tuberous begonias of drooping habit of growth. j hese make ideal subjects for suspended baskets. Tho long, slender growths hang over tho sides and produco masses of bloom. The treatment is similar to those intended for pots, but in this caso_ the final shift is into the basket. A similar compost will suit them, and the baskets should be lined with sphagnum moss to retain the moisture. FLOWERING SHRUBS PRUNING NOW NECESSARY Larlv flowering shrubs, which were in full beauty in winter and early spring, should be pruned in September. The Winter Jasmine and the Winter Sweet (Chimonanthus fragrans), the winter flowering Heathers, Erica mediterranca, and E.carnea, lnurustiniis (Viburnum Tinus), and the Witch Hazels should be given what pruning they require. The Winter Jasmine can he pruned slightly or severely, according to the position in which it is grown. If on a trellis it is sufficient to cut out a few of the old weak stems and cut back straggling shoots. The Winter Sweet is pruned by shortening the side shoots of the previous year's growth to within two or three buds of the base. It is merely necessary to cut off .the dead bloom from heathers. As these early flowering shrubs produco their blooms on shoots of the previous summer's growth they are pruned in September, and then have the whole summer to grow before flowering again. Shrubs which bloom in lilte summer and autumn are pruned now so that they may produce fresh, vigorous shoots 011 which flowers are borne. Clematis of the .Tackinanni type, for example, which bloom from December onwards, are cut back now to within lOin. of the base of the previous summer's growth, ranuliar varieties of this type are Comtesso de Bouchard, the purple Jackmanni, Gipsy Queen, and Mine. E. Andre. Varieties of Clematis viticella, which also bloom in late summer, need similar treatment.