Cultural Pointers 
SOILS 
Chrysanthemums will grow in a wide range of soil types but a fibrous silt loam is preferred. 
Blue grass sod to which rotted manure has been added plus an application of super phosphate will 
give excellent results. Porosity to permit penetration of water and a uniform supply of fertilizer are 
the reasons for the great care in soil preparation. If water remains on the surface of your soil for 
more than a few moments after watering your soil is not of good structure. 
Acidity 
Evidence shows that the soil reaction should be slightly acid pH 6.5, although in many instances a 
neutral medium does very well. If your soil tests slightly alkaline apply !/2 to one pound of agricultural 
sulfur per 100 square feet of area. However, if your soil is acid apply 3 to 5 pounds of agricultural 
ground limestone per 100 square feet of area. 
Steam Sterlization 
Steam sterilization is the only practical means known to destroy the verticillium wilt organisms present 
in many soils. The cuttings you purchase are free from wilt but if planted in soil that is not steam 
sterilized many will contract the trouble. 
Old soil when properly managed will give comparable results with fresh soil. Add a quarter of the 
volume of humus in the form of manure or peat moss. Steam sterilize to destroy the verticillium wilt 
fungus as well as improve the structure of the soil. Steam sterilization may be done with the use of 
three inch tile or down spouting with '/g holes drilled every six inches on each side of the pipe. Use 
two lines in a three and one-half foot bench. Ridge the soil to the center of the bench directly over 
the lines, covering with tarpaulin, canvas or sisalkraft. The Thomas method is very similar with the 
exception that the pipe is laid on top of the rototilled soil and then covered so as to make it air- 
tight. The Thomas method is not recommended where purlin posts are in the bench. 
By introducing the steam in the center of a 100 foot bench and sending the steam both directions 
a more thorough sterilization is accomplished than if the steam were to be forced in at the end of 
the 100 foot bench. Cover the sides of the benches so that the entire bench and contents are heated 
to 180°F. Remove the covering one hour after the steam has been cut. This allows the excess moisture 
to pass from the soil as vapor. Leach heavily immediately after sterilizing to reduce excess fertility. 
Chemical Sterilization 
A chemical which has proven its worth is Larvacide. This material must be used when the green- 
houses are empty to avoid injury to adjoining crops. This gas is applied in liquid form with a special 
applicator so that 2 or 3 c. c. are applied at 10 inch centers. The soil should be moist before apply- 
ing. A good suitable covering should be placed over the treated soil to keep the gas in the soil for 
at least 48 hours although a water seal applied 2 to 3 times every 24 hours will suffice. The soil 
temperature should be at least 60 degrees or higher. When used properly you can expect favorable 
control of insects, diseases and weed seeds. 
Dowfume MC 2 has been tried and found to control nematodes, weed seeds, and some damping 
off organisms. Best results are obtained when the soil temperature is above 60°F. About the same 
procedure should be followed in its application as that described for Larvacide, 
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Supporting Standards with the String Method Thomas Method of Steam Sterilization 
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