ANNUAL REPORT, 1941 77 



from 30 to 40 percent. Optimum temperature of the medium, one-third peat 

 and two-thirds sand, was found to be about 70° F. Hormodin A, 40 BTI units 

 for 24 hours, and Formula No. 66 each gave 95 percent good normal rooting. 



Propagation of Juniperus virginiana var. glauca. (Harold S. Tiffan>', Waltham.) 

 Several varietal forms of Juniperus virginiana are propagated commercially by 

 grafting to understocks of this species, since no satisfactory percentage of rooting 

 has been obtained from cuttings. The variety glauca is one of these. 



Preliminary trials in 1940 of wood of the current season and of two-year wood 

 gave high rooting percentages on the one-year wood and very low percentages of 

 rooting on. the two-year wood. Both sand and half sand, half peat appeared 

 satisfactory media, although cuttings in the sand-peat rooted satisfactorily in 

 11 weeks, while those in the sand consistently required 14 weeks. 



A series of cuttings, twenty to each treatment, taken in late January 1941, 

 were put in sand-peat in open unheated benches at a temperature averaging 62°. 

 Thirty-four treatments with root-inducing substances were made for 16, 24, and 

 40 hour immersions. 



Indications show successful rooting confined to indolebutyric acid treatments 

 with a range of rooting percentages up to 100. Untreated cuttings gave no 

 indication of rooting. A higher temperature of the rooting medium appears to 

 be necessary for best results. 



Factors Increasing the Rapidity of Growth of Nursery Stock. (Harold S. 

 Tiffanj', Waltham.) To determine best cultural practices for rapid quality 

 growth of lining out stock, plots of various plant materials have been laid out from 

 1939 through 1941. These include plantings of Tsiiga caroliniana and canadensis, 

 Thuja occidentalis var. glohosa, and Syringa vulgaris var. Souvenir de Ludwig 

 Spaeth. 



A series of fertilizer treatments was applied in duplicate, in 1940 and 1941, to 

 fourteen plots of Tsuga caroliniana. Treatments were based on 5-8-7 (one third 

 ton per acre) as a balanced fertilizer adequate in amount for the needs of young 

 evergreen trees. One-half the nitrogen was supplied b\' nitrate of soda and 

 one-half by suliate of ammonia. Phosphorus was supplied by superphosphate, and 

 potash by muriate of potash. Manure and peat moss represent two other treat- 

 ments. 



Growth measurements in inches for each of the years 1940 and 1941 were se- 

 cured from plots treated with manure (15 cords per acre) and peat moss (annual 

 application of 2 inches hoed into the soil). 



While other treatments also show measurements exceeding those of the un- 

 treated plots, further results are needed before conclusions can be drawn. 



Study of Herbaceous Perennial Material. (Harold S. TifTany, Waltham.) 

 Records of the 1941 season have been included with material previously obtained, 

 giving the average time and duration of bloom, height, and color of the better 

 and enduring garden perennials. Averages for a period of five years are now 

 available for most of the plants. 



Additions to the peony collection, chosen as representative of the best of their 

 types from a study made by the University of Illinois and the American Peony 

 Society, are as follows: Single — Catherine Parry, Departing Sun, Harriet Olney, 

 Le Jour, Marguerite Dessert, Mellin Knight, Mischief, Shirley Walker; Jap- 

 anese — Antwerpen, Cathedral, Fuyajo, Hakodate, Kukenu-Jishi, Margaret 

 Atwood, Mikado, Some-ganoko, Surugu. 



Hardiness Trials of Clematis Varieties. (Harold S. Tiffany, Waltham.) A 

 limited number of three-\'ear plants was set in the nursery, from pots, in the 



