Since many trees of the named varieties have been in bearing for a number of years it gives a broad field for studying them, and their habits are very similar to the native trees, I do not know of a single tree that is not a testimonial to the care and attention it has been given.
In my first nursery planting trees were left growing to supply bud and graftwood for future use. These were left entirely too close together to remain until large trees, but I have never yet had nerve enough to remove all that should be taken out, with the result that they are now crowding and robbing each other of food and moisture retarding both growth and bearing. These are now from 15 to 19 years old and not producing as many nuts as they did several years ago, or as many as trees several years younger that have more space. My observations convince me that plenty of space, food and moisture are most essential for best results.
The past four years has been a splendid time to study this as our weather conditions have been unusual in that we have in this section had both wet and dry seasons. I am firmly convinced that weather conditions have a great deal to do with the nut crop not only with the quantity of nuts but quality as well. Moisture conditions in spring and early summer determine the size of the nut, and later in the season the quality of the kernel. Plenty of moisture in spring and early summer will make a large size nut. After the shell once forms the growth of nut is done. Then the plumpness of the kernel depends on the amount of moisture after the shell is formed. Lack of moisture the entire season spells a small, poorly filled nut. Trees growing in a crowded position, or on hard, dry ground, seldom ever have all the moisture they need to produce a good crop of well filled nuts. This has been plainly demonstrated with my own and my neighbors' trees in the past few years.
The weather of the previous season also may have much to do with the crop the following season, especially with trees growing under adverse conditions. These conditions can often be largely overcome by the owner, with fertilizers and cultivation.
In planting a tree be sure to give it plenty of space. If the soil is lacking in plant food feed the tree, remembering it can draw food only from a given space. No one would expect to grow the same farm crop on a plot of ground for many years without fertilizer. Prepare to conserve moisture for the hot, dry season either by cultivation or mulching. One of the thriftiest best bearing nut tree plantings I know of is on very sharp, hilly clay ground in Rockport, but the owner fertilizes these trees annually and gives splendid cultivation.