6 
COLORADO EXPERIMENT STATION 
with the soil. Frequent light applications are preferable to heavy and ir¬ 
regular ones, as they tend to promote more uniform growth and yields. 
Pruning. In western Colorado at least, dewberries are allowed to grow 
prostrate, growers say it is too expensive to trellis them and it might be 
added that the present system seems highly satisfactory. No doubt, under 
certain conditions, trellising would be advisable but surely could not in¬ 
crease the yield any considerable amount. Where the plants are grown on 
a trellis, they receive no summer pruning as a rule; the new canes are al¬ 
lowed to trail on the ground under the trellis while the fruiting canes are 
tied to the wires. The only pruning the plant requires—unless it be a clip¬ 
ping back in August to induce early maturity—is cutting out the old canes in 
the fall or spring and shortening the new ones to three or three and one- 
half feet. A two-wire trellis is generally used, the top wire being about 
three feet from the ground. The training of the dewberry without the 
trellis requires a little more care in pruning but saves the labor of tying up 
and allows of early cultivation either way. The first pruning consists in 
tipp'ng the new growths when they have attained a length of twelve or 
eighteen inches, the canes then stand upright above the old wood and the 
tips may be mowed off with a sickle or large knife. It is important that this 
pruning be done at the right time, do not wait until the canes are longer and 
then cut back to eighteen inches or weak lateral canes will be the result. 
This early pruning forces out lateral canes and thus increases the bearing 
surface as well as stiffen the lower part of the cane, making it support itself 
better. The general practice is to prune the second time just before picking 
begins. The main object of the pruning seems to be to get the new wood 
out of the way of the pickers. At this time the lateral canes forced by the 
first pruning are cut back to two or two and one-half feet, they should be 
left long enough to shade the old wood and the fruit, yet short enough to 
be easily lifted by the pickers. This pruning must not be delayed too long 
as it starts new growth which should have time to mature, at its best it is 
not satisfactory and it is probable that the growers will yet learn to avoid 
this pruning. The third pruning is administered the following spring, and 
consists in removing all old canes and shortening-in the new canes that may 
have grown too long. There seems to be no reason why this pruning may 
not be done before covering in the fall other than that the foliage makes 
the pruning more difficult. 
Winter Protection. The dewberry is not hardy in most parts of Colo¬ 
rado. consequently the canes must be covered during the winter. The dif¬ 
ficulty seems to be that the canes do not mature well before frost and they 
tend to dry out during the dry winter weather. Just before the ground 
freezes it is the common practice to bunch together the canes from each 
plant and cover them with a light covering of soil. Where the vines are 
al’owed to grow together in the rows, they are kicked apart, strung out, and 
covered in the open middle. The covering of dirt need not be heavy, just 
enough to hold the plants down throughout the winter. There is danger in 
covering the plants too deep, especially if they carry heavy foliage, as the 
canes are liable to become heated. The bare bases of the canes should be 
well covered. Most growers cover with a shovel, one man covering about 
1500 p’ants in a day. The vines must be uncovered in the spring before 
growth starts. The canes are not injured by light spring freezes, and the 
new growth that starts while the vines are still covered is either knocked 
off in the process of uncovering or is killed by the hot sun afterward. 
The canes may be lifted with a fork and the dirt scraped away from 
about the crown, leaving the rest of the leveling to the cultivator. 
Picking. In growing dewberries on a large scale one of the serious 
problems is that of securing pickers. The average picker will pick from 
five to seven crates a day. and this means that it will take from eight to ten 
average pickers to pick an acre per day. The general practice is to pick 
every third day, and the large patch may be divided so as to furnish the 
pickers employment every day. 
V 
