THE AVOCADO 29 



soft and porous, and in the process of erosion has broken down 

 unequally, leaving a jagged surface or the characteristic pot- 

 hole formation. When first grubbed it crumbles and is readily 

 worked, but on exposure to the air it gradually hardens, owing 

 to the deposition of carbonate of lime following evaporation of 

 the moisture held in the interstices. 



The growth made by the avocado upon this rocky land is 

 rather remarkable ; it seems, in fact, that young orchards have 

 done better around Homestead, where the rock comes to the 

 surface, than they have in those areas north of Miami where 

 there are six to eighteen inches of sand on top of the rock. 

 The reason for this may lie in the moisture-retaining proper- 

 ties of this soft limestone; the roots, which are always close 

 to the surface, here probably are kept more uniformly supplied 

 with moisture during a period of dry weather than on light 

 sandy soils which dry out rapidly. 



The heavier Florida soils seem to be much more favorable 

 to the growth of the tree than light sands. A yellowish or 

 brownish subsoil in many parts of Florida indicates good 

 avocado land. The avocado prefers a moist heavy loam, and 

 the closer this can be approached the better will be the results. 



The soils of California are probably more nearly ideal for 

 avocado culture than any of those in southern Florida. Sandy 

 loam, which is abundant in the southern part of the state, pro- 

 duces excellent growth and is giving good results. Adobe 

 does not seem so desirable, yet good trees have been grown 

 upon it at Orange. 



Red clay has been satisfactory in Cuba and Central America, 

 while heavy clay where well drained has produced good trees 

 in Porto Rico. 



Many problems connected with avocado culture remain 

 to be solved. One of the most important is the adaptability 

 of the tree to low wet lands in southern Florida. It has been 

 the general opinion that avocados should not be planted on 



