THE NATIONAL NURSERYMAN 
413 
shape them for ordinary orchard purposes. Naturally, at the 
close of the first summer’s growth, a larger percentage of new 
growth would be removed from the autumn-planted trees 
because their limbs were longer. The difference in the 
amount of length, growth and diameter of these autumn and 
spring-transplanted trees was not the most significant point 
observed, in the comparative studies of the two groups. 
In addition to these 20 trees, a large number were planted 
in autumn and a corresponding number in spring to be dug 
at different times for the purpose of root study and other 
observations. It was noticeable that new root growth began 
to form very quickly on the trees planted in autumn. Callus 
formed abundantly wherever a large root was cut back in 
transplanting in the autumn. The wounds began healing 
quickly wherever a branch was cut off close to the main stem, 
even tho the pruning was done as late as November. This 
autumn formation of new tissue about the wound, callus of 
the cut back roots and the abundant new root growth in¬ 
dicated that at the time of transplanting in autumn the plant 
food materials stored within the tree were in a condition to be 
transported to and utilized at points where it was needed for 
growth. It is probable that after trees have come into more 
permanent winter conditions the stored food compounds 
within reach a more stable form, in which they are less soluble 
and are less capable of being carried to any part of the tree for 
healing use or for storage. In other words, in the autumn- 
transplanted trees growth was going on; but it was the growth 
of healing and storage where needed, and there was no visible 
pushing of the buds or growing tips, the trees remaining 
dormant. This abundant autumn root growth continued 
until very cold weather in December. Some trees were taken 
up even after the ground began to freeze on top and there were 
evidences that tender new root growth was still continuing. 
Apparently, root growth on autumn-transplanted trees does 
not cease until the ground freezes deep enough for the frost to 
reach any growing root in question. 
Fall Planting Favors Root-Growth 
Comparing the root-growth made on these autumn 
transplanted trees with observation made on the same days 
on untransplanted trees remaining in the nursery, it is evident 
that the transplanted trees were even making more rapid 
progress in healing root wounds and in putting out new roots 
than were the trees in the nursery which had not been trans¬ 
planted. Apparently the untransplanted trees in the nursery 
do not continue root growth to the same degree that root 
growth will progress on the trees, provided they are trans¬ 
planted in the autumn. In other words, it seems to me that 
the tree is capable of responding to the call for quick establish¬ 
ment of new root system when it is transplanted in the fall, 
and that available plant food being stored and carried over in 
this stable condition is partly used in the autumn to meet this 
demand for new root system or for the healing of wounds. 
Observations made on spring transplanted trees showed 
that they do not quickly begin to make new roots in spring. 
They were out in full leaf and apparently making good 
progress above ground before any root growth could be 
detected below ground. It seemed as if available stored food 
in the trees was carried to the growing points above ground 
and utilized to make new growth there more readily that it 
was carried to the wounds of the roots to make calluses or to 
make‘new roots. Root growth did not begin in spring 
transplanted trees until the soil had gotten quite warm some¬ 
what late in the season. In fact, root growth below ground 
did not begin to form abundantly until June, about two 
months after the trees had been transplanted in the spring. 
Pairs of trees taken up each month during the summer showed 
those transplanted in the autumn had much larger root 
growth than those transplanted in the spring. 
It is a well known fact that our soil is warmer in the autum 
than it is in the spring, even though atmospheric temperature 
may be the same. The greatest sum total of heat stored in 
the soil does not occur during the hottest part of summer, but 
somewhat late in autumn after the atmosphere begins to cool 
off. The surface of the soil is warmed in hot weather. It 
continues to warm up to greater and greater depth as the 
season progresses. At a given distance below the surface in 
any soil formation, we reach a point where the soil is no longer 
affected by this summer warning. In other words, at no 
great depth below the surface we reach a layer where we have 
a constant temperature summer and winter. This storage of 
heat reaches its greatest depth in autumn. This heat is given 
off during autumn and winter. It seems possible that the 
release of this enormous quantity of heat stored in the soil 
may furnish conditions to the autumn transplanted trees 
almost akin' to mild bottom heat in hot beds. Spring- 
transplanted trees have no such warmed layer of soil beneath, 
as the soil has lost its store of heat. In connection with this 
suggestion it is of interest to note that toward the South, 
especially where summers are long and hot, cuttings put in in 
the open in autumn root much more readily than they do in 
the north when put in either autumn or spring. Some 
species which do not root readily from cutting at any season 
of the year in the North may root readily from autumn made 
cuttings in the South. Cuttings from pear orchards in 
Texas and inserted in the fall readily make well rooted trees 
while as far north as Missouri it is difficult to root pears from 
cuttings at all. Even the persimmon, one of the most difficult 
of trees to propagate by means of cuttings in Missouri, will 
root quite readily from autumn made cuttings in Texas or the 
Gulf region. 
Observations on other trees than those whose measure¬ 
ments are recorded above lead the writer to believe that 
apples, pears, hardy plums and cherries generally do better in 
Missouri if transplanted in autumn than they do when 
transplanted in the spring. Peach trees and some tender or 
only half-hardy ornamentals seem safer when transplanted in 
the spring. If an autumn-transplanted tree does not make a 
root system before cold weather comes on, it will not be in a 
condition to as well withstand winter killing during the 
winter as if it remained in the nursery with the entire root 
system intact. For that reason it seems wise, where autumn 
planting is to be done, to plant as early in autumn as is 
feasible; that is, as soon as the leaves can be stripped safely 
from the trees. Caution should be added, however, against 
stripping the leaves in autumn too early, as this is undoubtedly 
injurious. Leaves should not be stripped off until they show 
a tendency to begin to come readily from the trees. It seems 
