There really are non-chemical
solutions, but they require a combination of relaxation, hard work,
landscape cloth, and as a last resort, goats.
First, relax. You don't
have to elimate all the blackberries in western Oregon. In fact,
if someone could wave a magic wand and get rid of them all, there
would be a sharp drop in the bird populations that use them for
shelter and food. And who really wants to give up those delicious
blackberry pies and cobblers?
Now, the hard work.
Cutting the blackberries
back:
The most effective non-toxic
way to eliminate a large infestation of blackberries is to mow them
for three years in a row. Removing all new leaf growth will deprive
the roots of food and they will eventually die. Make sure you keep
all green growth cut down, which could mean doing it two to four
times per year. Within three years, the plants will weaken and die.
Without photosynthesis they cannot maintain their roots.
This will probably require
a brush mower or a tractor mower. Check out our Coastal
Resources page to see which local rental stores rent out the
necessary equipment to deal with your blackberries. These stores
have dealt with this sort of thing for many years, and can recommend
the equipment you will need.
If the infestation is
small enough or laborers plentiful, blackberries can be cut to the
ground with loppers. Smaller vines, especially the tender new growth,
can be cut with a weed eater.
Grubbing out the roots
will help, as long as this is done in late fall or winter when the
earth is soft and new growth won't be stimulated. The site should
be replanted with trees or shrubs which will shade out any blackberries
that resprout.
If you prefer a meadow,
the ground can be seeded with grass as soon as the vines are cut.
A basic meadow will result if maintenance mowing is continued
on a regular basis. Each year the number of blackberry sprouts
will diminish and the grass will increase. Withhold fertilizer
until the blackberries disappear.
Landscape fabric:
Cut the vines to the
ground as in the previous methods. Then cover the soil with heavy
duty landscape fabric. Pin it down with ground staples or weight
it well and cover with bark mulch. Eight or ten mil black plastic
sheeting may be used instead of landscape fabric.
Note: To use
this space creatively, a temporary container garden may be made
on top of this work in progress. Wood chips or straw may be lightly
strewn to improve aesthetics.
Option: A permanent
stone garden could also be made at this point. Leave the landscape
fabric or black plastic down and mulch the area with flat or rounded
stones, landscape paving (cement or brick), or alternate patterns
of stones/wood chips/brick, etc. Landscape cloth or plastic sheeting
which is covered (for instance with wood chips) lasts for years.
This is a whole lot of fun, and weed control remains intact!
Another option:
Leave the area covered until you are ready to clear the roots.
Then dig or till the weakened root systems starting 12 months
after the initial cutting, removing all roots. If you are not
planting immediately, re-cover until planting time.
Fertilize and plant
as desired. Make sure you pull any berry seedlings if you see
them.
Goading the
goats
If your site
is too rocky or steep for a brush mower, consider borrowing or renting
some goats, which are said to find blackberry plants quite tasty.
Of course there are other considerations. Can you keep the goats
from eating desirable plantings, and can you supply the goats with
water, provide adequate fencing or tethering, and fulfill other
responsibilities of animal stewardship? For some people, handling
goats will seem more difficult than three years of mowing.
