) On the other hand,
objections to their use are that they are often left in so long that
they crowd and seriously injure the permanent trees, and that their
care often requires different operations and at different times from
the other trees, such as spraying, which may result in injury to the
permanent trees in the orchard.

Trees used as fillers for apples should have two important
characteristics; they should be rapid, vigorous growers and should
come into bearing at a very early age. Two kinds of fillers are
available, those of the same species, which may be either dwarf or
standard trees, and those of a different species, of which peaches and
plums, and possibly pears, are the best adapted. Dwarf trees may be
dismissed from our plans with the statement that they have rarely
proved profitable under ordinary conditions, as they are much more
difficult to grow than standards and when grown they have but few
advantages over them. The varieties of standard apples which are
advisable as fillers have been indicated in Chapter II.

The use of peaches and the Japanese plums, both of which make
excellent fillers because they grow rapidly and come to heavy bearing
quickly, is limited to their soil and climatic adaptation. They are
adapted to the lighter phases of soil and the more moderate climates
and under other conditions are impracticable. On heavier soils and in
more rigorous climates the European plums and the more rapid and early
bearing pears, such as the Keiffer, make fairly good fillers.

On the whole, the writer is inclined to advise the use of fillers in
the general farm orchard. Quicker returns from an investment of this
nature, which is usually heavy and which at best must be put off
several years, are very important. Under careful and intelligent
management the objections to their use are easily overcome.

SPACING AND ARRANGEMENT OF TREES.--The distance apart of planting
depends on the variety planted. Close headed, upright growing trees
may be planted closer together than spreading varieties. Some
varieties grow larger than others, and the same variety may vary in
size on different soils. It is seldom advisable to plant standard
apple trees in the latitude of New York closer than thirty feet, or
farther apart than fifty feet. Trees of the nature of Twenty Ounce and
Oldenburg (Dutchess) should be planted from thirty-two to thirty-six
feet apart, while Baldwins, Rhode Island Greenings, and Northern Spies
r