plied with humiis combines the advantages and eliminates the 

 disadvantages of both the preceding types. 



For growing irises, therefore, a heavy soil may be greatly im- 

 proved by the addition of sand, sifted coal ashes, wood ashes, 

 gypsum (sometimes called "land plaster") or pulverized lime- 

 stone. The latter material I prefer to hydrated lime for this 

 purpose. It is slower acting but less caustic and has a better 

 effect on the mechanical condition of the soil. Also, for very 

 heavy soils larger quantities of it may be used without getting 

 an excess of lime — application of 15 to 20 pounds to the hundred 

 square feet being perfectly safe, for beardless irises particu- 

 larly. Japanese irises using aluminum sulphate instead of lime 

 especially if the soil has been previously limed. 



For light sandy soils inclined to be too porous or open, gyp- 

 sum or limestone is effective in impro^dng the mechanical con- 

 dition. Manure, often recommended for improving light sandy 

 soil, should not be used unless it is so old and decayed as to 

 have become practically black soil. Many soils are benefited by 

 the addition of peat moss which helps retain both soil moisture 

 and plant food. For the bearded irises mix one-half to one 

 pound of lime to each cubic yard of peat moss. 



Sub-Drainage 



Indifferent though most irises are to the character of the soil 

 in which they grow, when it comes to drainage they are among 

 the most particular of plants. . . . Bearded irises simply must 

 have good drainage to survive, and even the beardless irises 

 which may reli.sh an abundance of moisture during most of the 

 growing season will do well only where the surface soil is thor- 

 oughly drained, and will actually perish where it is wet up to 

 and around the root stalks. 



If the soil is naturally heavy or poorly drained it may be 

 necessary to excavate 12 to 18 inches where the bed is to be 

 planted, filling in with 6 inches or so of cinders, gravel, or other 

 drainage material. This, however, will be required only in 

 extreme cases. 



Fertilizer 



Sheep manure, tankage, and many other fertilizers good for 

 most garden flowers are rather too rich in nitrogen for irises. 

 They result in a lush but soft growth of the foliage and poorer 

 rather than better bloom. They may be employed temporarily 

 as a mild stimulus as the buds are forming but should not be 

 used to any extent throughout the season. I have used with 

 great success in preparing the ground for irises both bone meal 

 (both coarse and fine, mixing half and half) and a generous 



-in 



