PROPAGATION OF TREES AND SHRUBS 19 



here July 1 and there was good rooting of cuttings of C. acutifolia, C. hori- 

 sontalis (14), and C. adpressa (67) taken at or about that time. Cuttings of 

 harder wood are also used. Those of C. microphylla rooted 100 percent when 

 taken here in September. Cuttings of C. horisontalis which were taken here 

 in early August rooted 61 percent without treatment, 74 percent after treat- 

 ment with indolebutyric acid (50 mg./l., 16 hr.). Rooting of October cuttings 

 of C. microphylla was merely hastened by similar treatment (125). Sand is a 

 good rooting medium for that species (125), and it is better than sand-peat 

 for summer cuttings of C. divaricata and C. horisontalis. 



Cryptomcria japonica. Summer and fall cuttings will root, although slowly 

 (124). Effective concentrations of indolebutyric acid for December cut- 

 tings are 40 to 80 mg./l., 24 hr., 4 to 10 mg./cc. by the concentrated 

 solution-dip method (49), or 12 mg./gm. talc (61). 



Cupressus macrocarpa, Monterey cypress. Cuttings responded to treatment 

 with indolebutyric acid 40 to 80 mg./l., 24 hr., or 12 mg./gm. talc (61). 



Cydonia oblonga, quince. Softwood cuttings which were treated with indole- 

 butyric acid (20 mg./l., 24 hr.) rooted well if taken in spring while still 

 growing but not if taken a little later than that (81). 



Cytisus. Cuttings are made of nearly ripe wood (7) in late summer or fall. 

 Cuttings of C. Beanii and C. ptirgans, treated or not, rooted more than 90 

 percent in sand when taken here in early November. It is English practice 

 to root cuttings in sandy soil and to make them with a heel (80, 105). Cut- 

 tings of C. supinus, made without a heel, rooted better with the basal cut a 

 half inch below a node rather than at or above one (14). Cuttings of a 

 hybrid which were taken here in late October rooted 69 percent without 

 treatment, 100 percent after treatment with indolebutyric acid (75 mg./I., 

 20 hr.). Rooting of cuttings of one species was improved by treatment 

 with indoleacetic acid (40 mg./l, 24 hr.) (47). 



Daphne. D. Genkwa is easily propagated by cuttings taken while still very 

 soft (108). D. Mescreum, mezereum, can be propagated, although not very 

 easily (73), by cuttings taken in the fall (51). Fall, November, cuttings 

 of D. Laureola rooted 100 percent in 12 weeks after treatment with indole- 

 acetic acid (50 mg./l. 24 hr.) (68). Fall cuttings of D. odora rooted 80 per- 

 cent in 6 weeks after treatment with indoleacetic acid (100 mg./l., 18 hr.), 

 14 percent without treatment (25). D. Cneo^Mi can be propagated by cut- 

 tings taken in summer or in fall. Untreated cuttings taken here in July 

 and December rooted more than 80 percent in sand, less well in sand- 

 peat. December cuttings rooted 56 percent in 6 weeks after treatment 

 with indoleacetic acid (100 mg./l, 16 hr.), not at all meanwhile without 

 treatment (21). Summer cuttings are not very responsive to treatments 

 with indolebutyric acid (83, 125). Rooting of cuttings taken here in Sep- 

 tember was at least hastened, however, by 50 mg./l., 5 hr., for, in 9 weeks, 

 with some unrooted cuttings still living, there was 66 percent rooting of 

 treated cuttings, 20 percent rooting of the untreated. 



Davidia involucrata, dove-tree. Cuttings, made of side shoots or twigs with 

 a heel (80), are taken in late summer (8) or when the wood is firm (105). 

 Their rooting, usually not good (64), was somewhat improved by treat- 

 ment with indoleacetic acid (100 mg./l, 24 hr.) (87). 



Deutsia. Untreated softwood, July, cuttings of D. Lcmoinei (66) and 

 D. gracilis (14) rooted 100 percent in sand but rooting of similar cuttings of 

 D. scabra was at least hastened by naphthaleneacetic acid or indolebutyric 

 acid (1:1000, in talc), the former giving the better results (34) Hardwood, 



