University of Vermont Extension
Department of Plant and Soil Science
PRUNING BERRY BUSHES
Dr. Leonard Perry, Extension
University of Vermont
bushes such as raspberries and blackberries are generally referred
“brambles”. By knowing a few facts on
how they grow, you will be able to prune them easily, keeping your
productive for many years. For most
gardeners just growing raspberries, the main pruning to keep in mind
is to cut
out canes after they’ve fruited, and to thin out canes early each
summer to 6
inches or more apart.
pruning is perhaps the main point to making sure you have good
of course that you’ve chosen selections that are hardy in your
area. Without pruning, your berry patch will fill
with old canes and both plant vigor and yields will go down. With
proper pruning, you should get good
harvests from your bushes for 10 to 30 years.
most brambles have thorns, a useful tool is a pair of long-handled
addition to regular hand pruners. I also
like to use rose gloves—those with long gauntlets to protect your
arms. Once pruned, remove the debris away from
plants, to the landfill, or burn as insects love to live in such
come in two types—those that bloom on canes (those shoots from the
were formed last year (sometimes seen as “floricanes”), and those
that bloom on
canes that form the current year (also called “primocanes”). Most
the raspberries you’re familiar with
that fruit in mid-summer are the former, or “floricane-bearing”.
This is important to know since if you cut
the canes after only the first year, you won’t get any fruit. And,
after the second year-old canes fruit they
wont fruit anymore, so can be cut off at ground level—either after
fruiting, in fall, or the following early spring. You can tell
these older canes as they are
generally a light brown, brittle, and more woody.
other type of raspberries includes those that fruit some in summer,
in fall. For this reason they may be called “two-crop” raspberries,
“everbearers” although this last name is misleading. The
fall crop is produced on the primocanes from that current season. I
like to prune off all shoots to the ground
in spring, sacrificing any summer fruit but allowing all the plant
energy to go
into producing a larger fall crop.
purple and black raspberries, and upright blackberries, “tip” or
canes in early summer. This keeps them
from getting too tall, and promotes more side branches and so more
second year. Prune off the top 3 to 6
inches when the canes are 3 to 4 feet high.
If you’re using a trellis system for support, you can wait until
are about 5 feet tall to tip back.
Then late next winter, in addition to
removing any broken or crossing branches, prune or tip back the
(those off of the main upright canes) to about 6 inches long (or for
blackberries to about 12 inches long).
As with the one-crop raspberries, prune out any canes that fruited
are in a warm area and can grow trailing blackberries, such as the
zone 5) ‘Chester’ or ‘Triple Crown’, leave the trailing shoots on
the first year. They’re easily protected
this way over winter with straw. Then,
the next spring, train these second year shoots onto a trellis.
Measuring up from the base of the plant, cut
off the lateral shoots from the lower two to three feet. For the
rest of the laterals, where the fruit
will be produced, tip them back to 2 to 4 inches long.
addition to pruning out old canes each year, along with those that
or crossing, you’ll want to thin out canes.
Brambles tend to spread where you don’t want them and to get too
thickly crowded. Too many shoots results in reduced air flow and
better chance of
too many shoots results in fewer and smaller fruit.
early summer, cut out new shoots which are weak or thin. Cut out
any new strong
shoots that are closer than 6 inches apart, or 12 inches
apart for the more vigorous blackberries.
You’ll also want to cut out shoots that are coming up beyond a
wide bed, if they’re not in a grassy strip that you keep mowed.
choosing brambles, other aspects of their culture, cultivars, and
lesser known brambles
such as the loganberry or boysenberry, can be found online
(homefruitgrowing.info) or from the Fruit
Gardener’s Bible by Lewis Hill and Leonard Perry.