STREET TREES. 101 
much thicker than this, and use Cottonwood, Willow or similar 
fast-growing trees to alternate with one of the kinds named as 
desirable, with the expectation of cutting out the less valuable 
when it shall have commenced to crowd the more desirable 
kinds. 
Planting. Provided the soil is in the proper condition, the 
next consideration is the proper planting of the tree. The prep- 
aration for this should consist in digging a hole of sufficient size 
to take in the roots without crowding. If the subsoil is very 
.solid clay, it should be thoroughly loosened up, and where prac- 
ticable it is a good plan to dig a trench to the loose soil over a 
water pipe or sewer, for by this means the roots get into loose 
soil, and drainage is secure, which is often much needed on such 
‘and. Sometimes a very stiff hardpan can be broken up to 
advantage by exploding a small dynamite cartridge in a deep 
hole made with a crowbar. 
Before Setting the trec, it should have all broken and 
dead roots cut off. It should then be set an inch or two deeper 
than it had been growing, the discoloration above the roots indi- 
cating the depth at which it had stood. If, however, good drain- 
age cannot be secured, the tree can be planted less deeply, and 
then have a mound made around it. Fill in about the roots 
slowly, being careful (should the tree have a great number of 
fibrous roots) to work the earth well in among them and under 
the butt of the tree. Fine soil, free from large stones, should be 
used for this purpose. Pack the soil in firmly, if reasonably dry, 
with the heels, or, better still, with a rammer, making it as solid 
as possible around the roots. The object in doing this is to 
leave no air spaces about them. It is not a good plan to put 
water into the hole before the tree is set, but it may be put in 
when the roots are just covered and allowed to soak away before 
the remaining soil is put in. Asa rule, however, little is gained 
by watering if the trees have not leafed out and the moist soil is 
packed firmly around the roots. Water is most needed after 
growth starts. 
Mulching. Newly planted street trees are much helped by 
a mulch of straw, hay or well-rotted manure. The latter is best, 
as it also furnishes plant food, but hot manure is liable to injure 
the trunk if piled against it. These materials prevent the soil 
