REPORT OF THE SUPERINTENDENT OF GARDENS. 205 
quire a first removal to nursery rows, where a further growth of two or 
three years may be allowed. All this will depend somewhat upon the 
purposes for which they are to beemployed. Trees for avenue or roadside 
planting require both age and size before being placed in their perma- 
nent positions; but in all such cases the trees should be transplanted 
from the seed-ground into nursery rows, where they remain until re- 
quired. : 
If it is intended to plant thickets or beits of trees for the purpose of 
sheltering and protecting exposed fields or building sites, the plants may 
be removed at once from the seed-rows to their permanent locations, 
without going through the preliminary treatment of prescribed nursery 
culture, as their management in plantations or beltings of limited width 
should be of the same general character. 
The best practical method of rapidly and effectually securing a Satis- 
factory artificial plantation of trees, is to prepare the soil by applying 
manures, ploughing, harrowing, and attending to other manipulations, 
as if for a crop of wheat or potatoes. Trees will not grow well on poor 
soils; in this respect they repay labor and expense in a similar manner 
to other cultivated crops. The plants should be set out in rows, which 
may be about 3 feet apart in each direction, which will admit of cultiva- 
tion the same as for a corn crop, and which will be found to be quite as 
essential in the growth of trees as it is in the raising of cotton or corn. 
Unless the plants are over 3 feet in height when removed, but little of 
pruning will be required at transplanting; but as it will be found im- 
practicable to secure all the roots it becomes a safe process to cut back 
the tops of the plants to some extent. It is not possible to do more than 
offer general directions in this matter, as the specific requirements vary 
almost with each individual plant. But after the first season all weak- 
looking, crooked, or otherwise unsatisfactory plants should be cut down 
to within a few inches of the ground, and if more than one shoot starts 
from these stumps, remove all but the best for the future tree. Such 
trees as the Catalpa and the Osage Orange, which yield valuable timber, 
but are naturally of low, branching, and crooked growth, can be drawn 
up, a8 it were, into clean, tall stems by cutting them down close to the 
ground after they have recovered from the check of transplanting. 
Fine timber can be produced with as much systematic certainty as 
fine corn. Thick planting and due regard to judicious thinning as the 
trees increase in size, together with pruning such branches as seem to 
interfere with the symmetrical growth of the tree, are some of the essen- 
tials in forest management, a subject which has not as yet received much 
attention in the United States. ' 
ORANGES, LEMONS, ETC. 
Several years ago the department imported from Europe a collection 
of the Citrus family, embracing many varieties of the Orange, Lemon, 
Lime, &c. The plants were in very bad condition when taken out of the 
packages, owing to detention on the voyage and other causes; most of 
them were denuded of foliage and very scant of roots. They were at 
once planted in pots and placed under suitable conditions for growth. 
It soon became evident that they were badly infested with a scale in- 
sect which greatly retarded their growth and prevented their propaga- 
tion and distribution. After the failure of many attempts to utterly 
eradicate this insect, the collection may now be said to be entirely rid 
of it. This has been effected by the persistent use of a small portion of 
coal oil applied in water. About one gill of astral oil in five gallons of wa- 
