410 THE NURSERY-MANUAL 



Rheum (Rhubarb. Pie-Plant. Wine-Plant). Polygonacece. 



Propagated by seeds and by division. Each division should 

 contain at least one bud or eye, with as much rhizome and root as 

 possible. Seeds may be sown where the plants are to stand, but will 

 not reproduce the varieties, and three years are required for the 

 plants to mature. 



Rhipsalis. Cadaceoe. 



Cuttings, after having been dried a few days, should be inserted 

 in coarse sand. See Cacti, page 261. 



Rhododendron. Ericaceae. 



Seeds are largely employed, but they are small and light, and 

 must be carefully handled. They are sown in spring in pans or 

 boxes in a soil of sandy peat, care being taken to cover them very 

 lightly and not to dislodge them when applying water. They are 

 handled in coldframes or in a cool house, and the young plants must 

 be shaded. The plants are commonly allowed to remain a year in 

 the boxes. 



The seeds should be sown in prepared boxes, half filled with 

 rocks or ashes, on which is placed a mixture of peat, leaf soil and 

 sand ; on top place a thin layer, about one-eighth inch, of finely sifted 

 moss. Water well and sow the seed on the top of the moss. If 

 kept shaded and the moss never allowed to become dry, the seeds 

 germinate readily in about five weeks. Sown the third week in 

 January they are ready to transplant in a peaty mixture by June. 

 Transplant about one inch apart in boxes four inches deep, with a 

 slight drainage at the bottom. These plants will be ready to 

 plant out-of-doors in frames the following May. Three inches of 

 growth are obtained with some species eight months after the 

 seed is sown. 



Low-growing plants are often layered. Cuttings of growing wood, 

 cut to a heel, are sometimes employed, being made in summer and 

 handled in a frame, but the percentage of rooted plants is of ten small. 



Rhododendrons are extensively grafted, the veneer method being 

 most used. The operation is performed on potted plants in late 

 summer or early fall, or sometimes in a cool house in early spring. 

 Most of the leaves are allowed to remain on the cion. The plants are 

 then placed in densely shaded cool frames (Fig. 47), and are nearly 

 covered with sphagnum. Various stocks are employed, but for 

 severe climates the hardy species, like R. catawbiense and R. maxi- 

 mum, are probably best. R. ponticum is extensively used in Europe, 



