CACTI 3 



issued a handbook of cactus culture {23). These helps have dissemi- 

 nated a better knowledge of methods to be employed, but the soil and 

 climatic conditions of Europe differ so materially from those of va- 

 rious parts of North America that their rules are not well adapted 

 to our own special needs. 



Cacti are now widely distributed in tropical and warm-temperate 

 regions throughout the world. They have become particularly 

 abundant in portions of Australia, South Africa, and India. In 

 Australia, especially where the hot and wet seasons coincide, certain 

 species of Opuntia (mainly of South American origin) have taken 

 possession of large areas. The prickly-pear nuisance there has be- 

 come a national problem, baffling the resources of the Government. 

 The problem may not be solved until the increase of population trans- 

 forms the princely pastoral holdings into cultivated fields. 



The growing interest in this group of plants in North America and 

 the inadaptability of rules for general gardening in growing them, 

 as well as of rules laid down for their special care by European 

 growers, have created a demand for a work that will include both 

 general and special rules that may be applied in any part of our 

 country. To meet this demand is the purpose of this bulletin. Nat- 

 urally, some of the material herein contained is compiled from the 

 experiences of others, but use of it is made only in so far as it agrees 

 with the experiences and observations gained during the years spent 

 in caring for the collection at the Missouri Botanical Garden, in 

 studying the plants in their native haunts throughout the South- 

 western States and Mexico, in examining many private collections, 

 and in growing collections under natural conditions in both Texas 

 and California. 



PROPAGATION 

 FROM SEEDS 



Most cacti yield seeds abundantly. Ordinarily, in this country, 

 few of these seeds germinate and develop into mature plants because 

 of unfavorable environment. The seeds are usually fertile, however, 

 and, when planted under proper conditions, a large percentage of 

 them will germinate and with a little care will produce mature 

 plants. 



The best soil for growing cacti from seed has proved to be a 

 thoroughly decomposed sod mixed with at least its own volume of 

 sand. After these ingredients have been carefully mixed they are 

 run through a sieve of about %-inch mesh, which removes any large 

 particles and all superfluous root fibers, making a loose soil which 

 drains readily. It is not necessary that the soil be rich in humus, 

 and manured soils should always be avoided because of their undue 

 tendency to hold moisture. They are also a medium for producing 

 germs of decay. An open, drainable soil is the chief requisite for 

 cultivating cacti. 



For germinating the seeds an ordinary 4-inch pot is very conven- 

 ient. New pots are preferable, but old pots may be used with safety 

 if thoroughly sterilized. Porous pots are soon covered with green 

 algae when left in a moist place for any considerable time. This 

 growth will spread over the surface of the soil in a close blanket 

 which precludes the free access of air and seriously retards the 



