TREE AND SHRUB LIST 211 



RHODODENDRON Continued 



CUTTINGS. Half-ripe wood is used and placed in sand benches 

 under glass. When they have callused they may be given a little 

 bottom heat. Heel cuttings will be the best sort to use. 

 GRAFTING. R. catawbiense and R. maximum are the best stocks; the 

 Belgian nurseries have been using mostly R. ponticum. Veneer 

 grafting is mostly practiced, although cleft and saddle grafting 

 may be used. Let the grafts be made low on the plants. Do not 

 head the stock plant back until the second year. Grafting is done 

 late in Summer, early in Autumn or in December; no wax is used, 

 but the union should be tied with sphagnum; keep the plants in a 

 humid condition and shaded. 



Greenhouse Grafting. This is described by Van Gleef in The Florists 9 

 Exchange of April 28, 1917, as follows: 



"The first part of December is the right time to start grafting. Only 

 the youngest shoots of the last Spring's growth can be used for cions. 

 The grafted plants are placed in the greenhouse, in a slanting po ition, 

 with the cion upward. The first four weeks they must not be dis- 

 turbed, except for a brief airing every morning. Keep the temperature 

 about 70 deg. to 75 deg. F. In four weeks they must be changed 

 around, and a small piece trimmed off the top of the wild stock. An- 

 other four weeks' time is needed before the cion is grown on the wild 

 stock, and two more are necessary to harden the plants off, before 

 they can be brought into a warmed frame. 



"Rhododendrons grafted in January and February undergo the 

 same treatment in the greenhouse, but do not need a heated frame 

 afterward, because when they are so far advanced that they can be 

 put into the frame, the most severe weather is past. In nice weather 

 the plants must be aired every day. 



"All that is left of the wild stock, Rhododendron ponticum, must be 

 cut off in March, then the cion starts to grow and gets its first shoot 

 very soon. It is advisable to remove the sashes on a rainy day in 

 April, so they may receive a good natural wetting. Lime must be 

 applied on the sashes when the sun gets stronger. The sashes are re- 

 moved entirely the first part of May, and for about two weeks it is 

 necessary only to protect the plants from the sun. After two weeks 

 they are ready to be planted out in the nursery as cultivated Rhodo- 

 dendrons. 



"They are planted 15 inches to 18 inches apart, because they are going 

 to stay there for three years until ready for shipment. Remove all the 

 growing buds from the tops of the young plants when transferring them 

 from the frame to the field, because that will make new branches sprout 

 from the sides. After planting nothing need be done to them, except 

 to protect them from the sun, which can be done by placing plenty of 

 leafy branches among the plants. Of course weeds should not be al- 

 lowed to grow, and occasionally the plants must be inspected to see if 

 any insects are appearing. Spray immediately if any appear. 



"The followng Spring to make bushy plants, growing buds and flower 

 buds must be removed again, and a little later on the plants must be 

 root-pruned, which is easily done with a little sharp, pointed, hand- 

 spade. This insures a ball of small fibrous roots. That Fall the Rho- 

 dodendrons are mostly 18 inches to 24 inches high, well budded, and 

 ready for the market. Most of the Rhododendrons are shipped in 

 Spring, however, but the nurseryman brings all his salable plants to- 

 gether and heels them in near his packing sheds in the Fall, so that 

 when the busy season arrives, the stock is handy and all he has to do is 

 pull it out of the trenches, pack and ship it. 



