PARK AND CEMETERY. 
193 
the disease, and the disease itself was prac- 
tically neglected. 
Under these circumstances radical meas- 
ures were necessary. Many of the larger 
American elms and other trees were headed 
in or pollarded, thus giving them a stubby 
appearance. While trees so headed in are 
much marred in their beauty, as compared 
with healthy ones not so treated, they, at 
least, look better than ones full of stag- 
head, and in time to come may recover 
much of the beauty of which they have 
been deprived. This heading in, while it re- 
lieved the trees of a mass of dead wood, at 
the same time removed many of the larvae. 
In addition to being beaded in, the trees 
were further very thoroughly treated by 
the methods already mentioned for killing 
the larvae. 
The elm bark borer is a pest of ap- 
parently recent introduction, but it is 
doubtful if it is of primary importance, 
since it seems to attack only trees already 
very much weakened. Elms which have 
been transplanted and so have been checked 
are sometimes attacked the first summer 
after transplanting. Sometimes such trees 
succumb that same season, or manage to 
pull through and revive the following sum- 
mer, not to be bothered any more by the 
pest. Attempts at remedial measures so 
far have proved unsatisfactory and reliance 
will rather have to be placed on preventive 
measures, such as keeping the trees in good 
I growing condition and cutting down and 
burning those badly infested. 
i 
i 
I 
In almost every instance the root devel- 
opment has been very marked, all kinds of 
trees having made an abundance of new, 
fibrous roots ; in some instances this devel- 
opment has been really quite astonishing, 
apparently exceeding many times over in 
volume that of the old roots which were 
cut off as a necessary incident to the soil 
improvement. Some of the comparatively 
young English, American and Scotch elms 
have in three seasons’ growth made new 
roots twenty feet long, measured from the 
point where the old roots were cut off and 
interspersed throughout the whole 36-inch 
depth of the improved soil, excepting, of 
course, near the surface. Even some of 
the old American elms made new roots fif- 
teen feet long. 
The effect on the growth of the trees 
above ground is not as marked ; this was 
not expected nor desired. However, in the 
areas first taken in hand (in the fall of 
1910 and the spring of 1911) almost all of 
the young English and American elms equal 
or excel in vigor, thrift and fine appearance 
— as evidenced by their luxuriant foliage, 
annual height growth, that peculiar sum- 
mer cracking of the bark so indicative of 
rapidly expanding tree trunk, and the 
rapid healing of wounds — elms of a simi- 
lar size to be found anywhere in the vicin- 
ity. The best English elms on the Public 
Garden in spite of more favorable con- 
ditions in the past, are not as vigorous 
and fine looking. 
The trees referred to, about forty-five 
in number, are located around the Brewer 
Fountain, near the southern entrance of 
the Park street subway station and else- 
where in the vicinity. It is only fair to say 
that they looked quite fine before they 
were taken in hand, although hardly as 
fine as since then. These trees if prop- 
erly taken care of should be good for 
another fifty or seventy-five years, and it 
is to be hoped that nothing will take place 
on the Common in the future to cause their 
taking off before old age comes upon them. 
In these same areas are a number of 
old American elms which look quite fair, 
especially when they are in leaf, and show 
the symptoms of vigor described in the case 
of the younger elms above, but of course 
not in so marked a manner ; most of the 
European lindens are looking well and 
the few pre-revolutionary English elms are 
at least holding their own and the one 
opposite West street looks quite exception- 
ally fine in summer. 
It is also a significant fact that, for 
about two years no dead or dying trees 
have been taken out of the first improved 
areas, except one or two small young trees 
lost in transplanting, but that during the 
same period, many dead or dying trees 
were still being taken out of the unim- 
proved areas or the more recently improved 
ones. 
The results mentioned undoubtedly are 
due to a combination of the various mea- 
sures adopted for the welfare of the trees 
— that is, the irrigation, the soil improve- 
ment, and the combating of insect pests. 
In the more recently treated areas most 
of the trees have already made marked 
new root growth and some are beginning 
to respond in their growth above ground, 
although there are quite a number still 
in such condition that they will have to be 
removed before very long, especially 
around the Frog Pond. Here and there 
a tree may have been seriously injured and 
its death accelerated by cutting too close 
to the roots. 
CONCLUSIONS AND FUTURE POLICY. 
Probably some mistakes have been made 
in the details of the work, but the prin- 
ciples are sound, and it should be pointed 
out that the trees on the Common are in 
far better shape than many trees in the 
suburbs which seem to be suffering from 
parallel conditions — that is, lack of mois- 
ture, insufficient and poor soil and insect 
pests — and where the per cent of loss has 
been vastly greater. On the Common the 
mortality has, in part, been reduced to a 
reasonable proportion and to quite an ex- 
tent things have taken a turn for the better 
and are on the mend. 
In comparing vegetation on the Com- 
mon with that on the Public Garden the 
vastly differing conditions should be taken 
into consideration. On the Public Gar- 
den the trees, as a rule, are younger; they 
have been copiously watered for some years 
past ; the water table is nearer the surface 
of the ground; the soil and subsoil appear 
to be somewhat better, as shown by test 
pits, than the soil and subsoil originally on 
the Common; and the public -is kept off the 
grass ; so the soil is not compacted around 
the trees. Also it should not be forgotten 
that within the last two years, even on 
the Public Garden, trees, eight in number, 
some being quite large elms, have been 
removed because they were in the same 
decrepit, staghead condition as were those 
which were removed on the Common ; also 
it has been found advisable to head in one 
large American elm. On the whole, how- 
ever, the Public Garden holds out en- 
couragement that the ravages of the leopard 
moth, which is about as abundant there 
as on the Common, can be kept within 
bounds if the trees are kept in good grow- 
ing condition. 
During the progress of the work eleven 
chemical analyses were made of the soil, 
comprising samples of the improved and 
the unimproved areas. These showed that 
some of the soil is still deficient in phos- 
phoric acid and lime. Based upon this 
fact and facts of horticultural practice, 
these two substances, in the improvement 
carried out in 1913, were used in about 
twice the proportion adopted in the pre- 
vious work. Therefore in all the areas 
improved previous to that time these sub- 
stances should still be added as top dress- 
ings — the former probably in the shape of 
acid phosphate, and the latter in the shape 
of pulverized lime stone. Also it would 
be well to add some soluble, available 
potash, notwithstanding that the total 
amount of this substance in the soil is quite 
large — but probably only slowly available. 
Copious watering should be continued 
in times of drought. 
Insect pests should be vigorously com- 
bated without letup, especially the leopard 
moth. 
In future plantings, earnest endeavor 
should be made to retain the fine effect of 
overarching American elms on the Charles 
and Beacon street malls, excepting at the 
upper and of the latter where English elms, 
as at present, might be perpetuated. In the 
other parts of the Common probably the 
main reliance should be placed on Eng- 
lish elms and European lindens, unless it 
be that, in the future, some less expensive 
way is discovered of coping with the 
leopard moth, or an immune race of 
American elms is developed. This latter 
idea is not so chimerical as it may appear 
to some, because, as already remarked, 
certain individual trees seem to be immune. 
If this proves to be the case it is only 
necessary to propagate from such individu- 
als by grafting in order to secure an im- 
mune race. 
