PLUM 
much more spreading and strong supporting system of 
roots. this has come to be generally recognized, 
and seedlings are now usually the rule. This is all- 
important in California, for there the roots of all plants 
must necessarily go deep for their moisture and nour- 
ishment. In fact, deep-rooting is the rule beyond all 
common expectation; thus almond roots the thick- 
ness of one's thumb have been found at a depth of 22 
feet-one of the many instances of the characteristic 
conditions of California agricultural practice 
Propagation is by both buds and grafts. The usual 
practice is to bud the young stock in July and August, 
and then in January and February following all those 
which have not taken can be grafted, thus securing two 
chances. When peach or almond is used as stock, 
budding alone is done, as these stocks have been found 
to take the graft poorly. The trees are not allowed to 
remain in nursery longer than one year after budding, 
and in many cases are set out the spring following, as 
"dormant buds." In California the 
necessity of deep and thorough prepa- 
ration of the land before planting the 
young trees cannot be too strongly em- 
phasized; for here the young tree 
must have every facility for getting 
its roots deeply and firmly established 
at the beginning, in order to enable it 
to withstand successfully the heat and 
drought of the long, arid summer. 
There has been much difference of 
opinion as to the proper distance for 
setting the trees apart and the mode 
of laying out the orchard. In early 
days the tendency was to rather close 
planting, in some cases as close as 16 
feet; but experience soon demonstrated 
the undesirability of too close proxim- 
ity, and later plantings were made with 
wider distances, until from 20 to 24 
feet has come to be the rule. The lay- 
ing out of orchards has caused much 
discussion, some asserting that the 
quincunx, hexagonal, and triangular 
systems secure better use of the land 
and allow better access to plow and 
cultivator than do the planting in 
squares. The square system, how- 
ever, has come to be most generally used. The style 
of tree was the next point of contention among the 
growers; but experience soon decided in favor of the 
low-headed tree of the vase-form, with rather more 
branches than usual. The early, high-headed, sprawl 
ing trees have now practically disappeared from the 
California orchards, notwithstanding the strong ob- 
jections at first offered against the low trees on the 
score of impeding easy cultivation. The prejudices 
have been overcome by the appreciation of the many 
advantages of a low, "stocky" tree, and the introduc- 
tion of improved implements. The rule now is to cut 
back the young trees at planting to from 18 to 24 inches. 
Until the top is formed the stems are protected, by 
whitewashing or wrapping with burlap, from the hot 
afternoon sun. The first year from 3 to 5 branches are 
allowed to grow from the stem, and these used to form 
the main limbs of the tree. From this time the prun- 
ing is done according to the usual methods for the 
vase-form tree, with the exception perhaps that se- 
verer cutting-back is practiced at first in order to give 
strength and stockiness to the limbs. In California 
the Plum is a most remarkable grower, often send- 
ing out shoots 10 feet long in one season and prone 
to overbear; and when anything but the severest 
shortening-in system during the first two seasons, at 
least, is adopted, the trees very soon break down with 
their loads of fruit. This has been emphasized again 
and again in some of the earlier improperly pruned 
orchards, where even propping proved ineffectual; the 
branches break at the bearing of the props, and when 
they do not break are so badly damaged from sunburn 
(to which the bark is extremely sensitive) that the tree 
is irreparably injured. After the third or fourth sea- 
son the growth of wood is much less and usually the 
pruning operations are confined to keeping the tree in 
PLUM 1377 
shape, removal of dead or damaged branches and short- 
ening-in the current season's growth to keep the young 
twigs in a vigorous growing condition and to prevent 
overbearing. 
One interesting exception to the usual practice might 
be mentioned here. On some Very rich, moist bottom- 
lands of the San Joaquin valley the long, slender 
branches are not cut back; in fact, they are encouraged 
by pruning back to the crown. The long, arching " canes" 
are allowed to remain until they have produced a crop 
(which they do in the second season with the greatest 
profusion), the ends resting upon the ground as the fruit 
gains weight. when these droop too low, they are cut 
back to the crown, when others will be produced to take 
their places. In this way enormous crops of fruit are 
produced on these lands, where, with ordinary treatment, 
the trees would run entirely to wood. 
Thorough and persistent tillage is one of the first 
principles of the California orchardist, for with him 
18s6. Damson 
(x 3/4). (See page 1373 ) 
the absence of summer rains makes the conservation 
of the winter rainfall an absolute necessity. Even 
in the summer-irrigated districts the soil is tilled and 
kept loose as soon as it is in proper condition, and no 
weeds allowed to rob the trees of the precious fluid. Up 
to three years ago, practically all the prune and Plum 
crop was produced without summer irrigation. Winter 
irrigation was often practiced and the water conserved in 
the soil by the usual methods of tillage. But the season of 
1897-8 was one of the driest in the history of the state, 
with less than one-third of the usual amount of rainfall. 
The use of summer irrigation was in some instances the 
only salvation of the trees. The installation of pumping 
plants and irrigation systems thereby received a great 
impetus, until, to-day, many orchards of importance 
are thus equipped, and the use of summer irrigation bids 
fair to remain a permanent practice, at least in the pro- 
duction of prunes. 
. As yet the California Plum-grower (and this indeed is 
generally true for all deciduous fruits) has hardly felt 
the need of extensive fertilization. the soils of the arid 
regions generally possess such high intrinsic fertility, 
and the tree-roots have such great depths from which 
to draw the nourishment and sustenance, that thus far 
they have been able to produce the enormous crops taken 
from the land without replenishment of the natural sup- 
plies. In some of the older orchards, however, the need 
of fertilization is beginning to be felt. In a great many 
the main deficiency has been found to be vegetable mat- 
ter, and, consequently, nitrogen. The extremely fine 
tilth which has been maintained has resulted in the de- 
struction of all natural green growth and the "burning 
out "of the humus, and has necessitated the call for a 
green-manure crop. This problem is rendered more dif- 
ficult in California by the fact that any such crop must 
be produced during the winter months and be ready to 
