32 TREES AND SHRUBS 



of the Rhus, as the sap of all is poisonous to a certain 

 extent. 



RiBES. — All the Ribes are improved by being cut 

 down annually while in a young state, but when 

 older, a yearly thinning out of the old wood is 

 sufficient, 



ROBINIA. — This is a genus that requires very little 

 pruning when the members of it have attained a 

 fair size, an occasional thinning being all that is 

 necessary. In a young state they require well 

 staking, and the longest shoots should be shortened 

 back, as many of them are top-heavy when young. 



Rosa. — Although the various garden Roses come 

 under this heading, yet they are a class apart, and 

 are better dealt with by specialists. The species 

 of Rosa do not require any shortening of their 

 shoots, which should always be left at full length, 

 but all of them should have an annual thinning out 

 of the old wood, either cutting it right away or 

 back to a young shoot. Some of the species are 

 very prone to throw up suckers from underground 

 sometimes to a considerable distance from the plant, 

 and these should always be dug out and got rid of ; 

 merely cutting them off only producing two evils in 

 the place of one. 



RUBUS. — This geniis includes the Blackberry and 

 Raspberry, and in a modified form the treatment 

 accorded to them for fruiting is the best to employ 

 with the ornamental Rubi, that is, all old wood that 

 has flowered should be cut away and strong young 

 canes encouraged. But while in the cultivation of 



