After planting, cultivation is sometimes used to control weeds; however,
there are several problems associated with continued cultivation.
These include increased erosion, trees blown over due to loose soil, and
the possibility of damaging root systems on larger trees. Cultivating close
enough to trees in order to control weeds also poses logistical problems.
Mowing is the more common practice to mechanically control weeds
between rows. Some of the limitations of mowing include difficulty in
getting close enough to the tree and the potential to damage branches of
larger trees. As trees grow, the area to be mowed decreases and the possibility
of damaging branches with large equipment increases.
from being caught by the mower tyres. Damage to the trunk of trees should be
avoided in all cases as it opens avenues for the entry of insects and disease.
of the equipment the grower already owns or plans to use. If trees are planted
on equal spacings, then the mowing can be done in two directions.
it is difficult to obtain adequate control immediately around the seedling or tree.
It has generally been found that mowing between rows and limiting chemicals
to the planting strip and tree row does the best all-around job.
an accepted and imperative practice. Although herbicides are expensive and
much care must be Taken during application to avoid tree injury, they are
extremely effective, especially in controlling weeds around the base of small trees.
Before applying any herbicide, a grower should follow label recommendations
and make sure that the herbicide may be used for the christmas tree species
being grown and the weed species to be controlled. The grower should also
learn whether weeds to be controlled are annual or perennial, grasses or
broadleaves and the stages of growth in which they are most easily controlled.
and rate of a herbicide. High organic matter and clay content in a soil can
“tie-up” certain herbicides and reduce their effectiveness. Coarse textured
soils high in sand content ties up less herbicide, and so less herbicide is
usually needed for effective control. Trees planted in coarse textured soils
may be more susceptible to injury from soil applied herbicides.