ANNUAL REPORT, 1947-48 59 



DEPARTMENT OF HORTICULTURE 

 Clark L. Thayer in Charge 



Study of Herbaceous Perennial MateriaL (C. J. Gilgut, Waltham.) The 

 test garden of herbaceous perennial flowering plants was visited throughout the 

 season by many people from Massachusetts and from other States. It will re- 

 main in its original location now that another site has been chosen for the pro- 

 posed new laboratory and administration building. 



A good blanket of snow, soon after the ground froze in the fall and during the 

 winter, protected the plants so that few were lost by winterkilling. Some re- 

 placements of plants lost for various reasons, and of old varieties superseded by 

 newer and more desirable varieties in the trade, have been made; but much more 

 replacement needs to be done, especially of Hemerocallis. Already a good start 

 has been made on a collection to include in this group of plants the newer colors 

 such as reds, pinks, apricots, and bicolors, and also plants of better habit and 

 more garden value. 



A buyer of phlox plants at present has no assurance that he will receive true 

 to name or even good phlox. On one order of eight named phlox from a mail 

 order nursery doing business nationally, six plants were the same — a worthless, 

 small-flowered, magenta-colored scrub seedling. Similar mixtures and also mis- 

 named plants have been received from other nurseries. 



The Delphinium collection has been augmented by addition of several strains 

 and by selections from our own plantings. 



Foliar nematode is a serious pest of outdoor chrysanthemums and the effective- 

 ness of sodium selenate in several forms, varying dosages, different methods and 

 time of application, as well as spraying at weekly intervals with wettable DDT 

 powder were tested. The results were inconclusive and the test is being repeated 

 this year." 



Control of Weeds in the Nursery by Chemical Sprays. (C. J. Gilgut, Waltham.) 

 Sovasol No. 5 was found to be a more desirable and effective weed-killer in the 

 nursery than 2,4-D ester formulations (Weedone, Weed-no-more 40, Weeded, 

 and Esteron) or the ammonium and sodium salts of the 2,4-D acid with which 

 it was compared. It killed grass and other weeds quickly and, when properly con- 

 trolled so that the spray did not strike nursery plants, caused no injury. Con- 

 centrations of 2,4-D necessary to kill grass caused delayed injury to nursery 

 plants, sometimes serious, from direct spray as well as from drift of vapors of 

 the volatile ester formulations, especially in hot weather. 



Early-season applications of Sovasol No. 5, when weeds were 4 inches high or 

 smaller, often gave weed control for as long as six weeks. In several cases two 

 or three applications were sufficient for the season, but in most cases applications 

 were needed at Intervals of about four weeks. Late March and early April 

 applications, when temperatures were 60° F. or less, gave good weed kill but not 

 as good nor as quick as later in the season when temperatures were above 70° F. 



In a nursery block of large plants, 5 to 6 feet high, large weeds were killed by 

 first scything and then spraying with Sovasol in hand sprayers at one-third the 

 cost of hoeing. 



Spraying rows of gladiolus corms and cormels at the first sign of emergence of 

 shoots through the soil gave excellent results and eliminated the first hand weed- 

 ing. The spraying was done with a 3-gallon pump-up hand sprayer, and the 

 spray applied at a moderate walk, as compared with hand weeding done tediously 

 and always on hands and knees. Hand weeding was necessary after the plants 

 were up because gladiolus Is easily injured by Sovasol. 



