12 



The Florists' Review 



July 28, 1914. 



ADVICE BY AN EXPERT. 



Fighting the Green Aphis. 



"The worst enemy of the sweet pea 

 is the green aphis, or so-called green 

 louse," says A. C. Zvolanek in his 

 brochure. "This insect usually comes 

 when the young plants are just breaking 

 through the soil; so you should keep a 

 continual watch on the plants as soon 

 as they begin to grow. If you see only 

 one or two in the whole greenhouse, do 

 not wait until there are more, because, 

 if you do, within a few days every 

 plant will be covered and soon will be 

 stunted if not entirely destroyed. The 

 best remedy for the green louse is to 

 spray with nicotine, or to fumigate 

 with nicotine paper, Aphis Punk. Fumi- 

 gating should be done only during cool 

 nights, when the temperature in the 

 greenhouse is not over 66 degrees, as 

 the plants are easily burned if fumi- 



fated in a higher temperature. About 

 our to six sticks of fumigating paper 

 may be used to one greenhouse 20x100 

 without injury. If the temperature, 

 even at night, is over 66 degrees, the 

 plants in the house should be sprayed 

 with a fine sprayer. Automatic air- 

 pressure sprayers are reasonable in 

 price and a great deal of work can be 

 done with one in a short time. Nico- 

 tine is usually about thirty per cent 

 strong. Only one part nicotine should 

 be used to 500 parts of water. The 

 spraying should be continued until not 

 a single louse is alive. During the 

 late fall or winter, after the cooler 

 weather has begun, fumigate once 

 every week, even though there are 

 no insects. 



To Prevent Mildew. 



"Mildew is sometimes destructive to 

 the plants, and is caused by a sudden 

 change in the temperature. To prevent 

 this, avoid opening the ventilators too 

 much at once, especially after water- 

 ing. As soon as the first mildew is 

 noticed, cut all the flowers and dust 

 the plants either with Grape Dust or 

 with the finest pulverized sulphur, add- 

 ing to it some air-slaked lime. After 

 about two days, syringe this oflf and 

 repeat if necessary. When applying 

 this be careful not to blow any on the 

 heating pipes, as the sulphur quickly 

 fumes on hot pipes, not only discolor- 

 ing the flowers and buds, but, i^ too 

 strong, damaging the foliage. 



"The red spider is also sometimes 

 troublesome, especially in early fall or 

 late spring. A good spraying with cool 

 water when first noticed will eradicate 

 this pest. 



Temperature and Ventilation. 



"After the seed has been sown, keep 

 the greenhouse as cool as possible, ad- 

 mitting air day and night as long as 



the weather will permit and there is 

 no danger of frost. The cooler it 

 is when the plants are started, the 

 stronger and healthier they become. It 

 is necessary late in the fall to start 

 firing. Keep the temperature from 40 

 to 44 degrees at night, never any 

 higher, for if it is kept too high the 

 young plants will begin to bloom too 

 soon, and before the roots have had a 

 good start. Such plants, forced in this 

 way, usually produce small flowers with 

 short stems and of no commercial 

 value. The winter sweet peas, if sown 

 in August or later, when well grown 

 should be at least thirty inches high 

 before showing the buds. The higher 

 they are in th^t stage, the better the 

 results. I would rather see sweet pea 

 plants showing the first buds when four 

 feet high than when two feet high, 



' ' Sometimes, during especially warm 

 and bright falls, the plants show a 

 tendency to bud too early. In this 



case I recommend picking all the buds 

 as soon as they appear. This ^vill 

 give the plants better root-growth for 

 the later crop. After the plants are 

 two and one-half to four feet high 

 they will all bud. This is the time to 

 raise the temperature, increasing it 

 every night by 1 or 2 degrees. If 

 the temperature averaged 44 degrees, 

 make it 45 degrees the next day, and 

 so on until 52 degrees is reached. This 

 is the highest temperature for the older 

 winter grandifloras at night. When in 

 bloom, 60 degrees during cloudy days 

 and 68 during bright days is best. 



"All the new winter orchid-flowering 

 sweet peas, in the first stage, need the 

 same treatment as that, just prescribed 

 for the winter-flowering sweet peas; 

 i. e., 40 to 45 degrees at night and 55 

 . to 65 during the daytime, according to 

 the weather, if bright or cloudy. But 

 after these are in bud and flower, raise 

 the temperature to 55 degrees at night, 

 60 to 65 degrees for cloudy days and 

 70 to 72 degrees during bright, sunny 

 days. This higher temperature is 

 necesssiry for the new strain, as the 

 flowers are twice as large and the 

 number of flowers to the stem twice 

 as many; and the additional warmth 

 prevents the falling of the buds and 

 causes the flowers to have brighter 

 colors. 



The Cause of Falling Buds. 



"We often hear of plants losing all 

 their buds. To prevent this, keep an 

 even temperature, especially during the 

 night. If, during a frosty night, the 



Basket Exhibited by Hendee Bros, at the Portland, Ore., Sweet Pea Show. 



