Offsets.
Rondeletia, Willdenovia, Rogiera. Rubiaceæ.
Seeds. Cuttings of half-ripened wood, inserted in sand under glass, in heat.
New varieties and sometimes stocks are grown from seeds, which are sown as soon as ripe, or kept in the hips until spring. The hardy kinds are usually sown in well-prepared beds out-doors. Roses are sometimes grown from layers, and often from root-cuttings, after the manner of blackberries. The common way of propagating roses, however, is by means of short cuttings of firm or nearly mature wood, handled under glass, with a mild bottom heat (of 65° or 70°). They are commonly made in February or March from forced plants. The cuttings are made in various fashions, some allowing most of the leaves to remain, and some preferring to cut most of them off, as in [Fig. 56]. They are commonly cut to one-bud lengths. Long cuttings of ripened wood, handled in a cool greenhouse or in frames, may also be employed for the various perpetual and climbing roses. Most growers feel that the best plants are obtained from cuttings, but most varieties do well when budded upon congenial and strong stocks. Budding by the common shield method is considerably employed, and veneer-grafting is sometimes used. The stocks are grown either from seeds or cuttings. The commonest stock is the manetti (Rosa canina), which is a strong and hardy species. The multiflora rose (R. polyantha) is also a good stock, especially for early results. A stock somewhat used about Boston for some of the hybrid perpetuals, with excellent results, is Rosa Watsonia, a Japanese species. “Worked” roses are in greater favor in Europe than in this country.
Rosemary (Rosmarinus officinalis). Labiatæ.
Seeds and divisions.
Rubus (Bramble). Rosaceæ.
Seeds, which should be stratified or sown as soon as ripe. Root-cuttings and suckers are mostly employed. The seeds of R. deliciosus require two years for germination. See [Blackberry], [Dewberry], [Raspberry].