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Successfully growing
blackberries, raspberries and other fruit-bearing plants
is often the result of good variety selection. Selecting
the right types of blackberries and raspberries can
eliminate the labor-intensive work of trellising, tying
canes and removing floricanes after they fruit. But
growing berries that mature in late summer and fall
involves not only good variety selection but also
non-standard orchard practices as well.
Most
blackberries and raspberries fruit on two-year-old wood.
The first year, the canes that emerge are called
primocanes and they do not fruit. The second year, the
same canes are called floricanes because they flower and
fruit. Today, though, fruit breeders have found and
developed primocane-bearing blackberries and
raspberries. That is, they bear on the current season’s
growth.
You can mow or cut the berry beds after
they fruit and not worry about tying or trellising. You
will need to put up temporary twine lines on both sides
of the beds to keep them from trying to bend to the
ground. This simple operation just takes a few minutes
per bed, not the hours of cutting, removing and tying
that is the standard operation for regular
floricane-producing varieties. A simple tall stake,
T-bar or post at the ends of the bed is all you need for
attaching these twine lines, and they can be removed for
mowing and easily replaced.
The culture for
growing primocane-fruiting raspberries is a little
different from growing primocane-fruiting blackberries.
Raspberries tend to be less vigorous than blackberries,
and the art of delaying fruiting can be easily
accomplished with raspberries. Primocane-fruiting
raspberries bloom and set fruit a little too early for
our Texas heat. If left with no control procedures, they
will bloom in late July and early August during the full
heat of summer. To delay blooming, use a procedure
called “tipping.” The most successful method of tipping
is to remove one to two inches of the tips of the canes
in early June or when the new canes reach three feet
high. They should be tipped again in early July,
regardless of height.
The first tipping will
cause laterals to form. For the second step, tip the
laterals as well as the new growth on the ends of the
first-cut canes. As berries form on the tips of the new
canes created by the tipping operation, you will have a
heavier crop and, most importantly, will delay blooming
until at least mid-August, when the heat is starting to
abate. The berries should start forming in late August
and early September, and continue blooming and fruiting
until frost, if you use the double tipping. What will
happen if you do not tip your raspberries? They will
bloom in July, form fruit in the middle of our summer
heat, and leave you with crumbly, dried-up berries. So
tipping is nearly a must for primocane-fruiting
raspberries.
For blackberries the tipping
operation needs to be done when the new canes reach
about 18 inches high and then again when the cut canes
produce laterals that reach 18 inches. This operation
needs to be controlled differently in various parts of
Texas because growing conditions are not the same
everywhere. To delay bloom time and produce more bloom
tips for heavier crops, adjust your tipping times
accordingly. It is best to do the second tipping
operation before the first blooms form or just as soon
as you see the first bloom bud. You want to make the
plants wait until the hottest part of the summer has
passed before they really start to bloom. You want fully
formed drupes and juicy berries, and you can have them
with this double tipping method of growing primocane
blackberries.
Also, if you do not mow or cut
primocane-fruiting blackberries in the second year, you
will have a very good floricane crop of blackberries.
This first floricane crop will usually be very heavy. To
take advantage of this good floricane crop, use a
rotation system that will allow you to do away with
trellising, tying of primocanes and removing old
floricanes.
Whether you have two beds or 200
beds, you can rotate your cropping. The first year you
plant half your beds, do the tipping and grow your first
primocane crop. You do not mow the canes at all that
first year. The second year, you plant the other half of
your beds. At the same time you let the first planting
bear its first floricane crop. After the floricanes have
finished fruiting, you let them produce a small
primocane crop. You will not need to tip the new
primocanes because bearing the floricane crop will delay
the fruiting of the primocanes. When the floricane and
primocane crops are finished, mow the first beds down.
Then in the third year you will have a floricane crop on
the second planting, and so on. No bed should ever go
more than two years without being mowed or cut down if
you want good production.
If you use this
rotation method, you can have two good crops of
blackberries a year (although from different beds). The
primocane-fruiting blackberries make this rotation
method possible.
So what about a rotation system
for raspberries? It does not seem to be a good idea at
this time to employ the rotation system for raspberries
because they have less vigor and are susceptible to
diseases. By mowing or cutting them every year, you
greatly decrease disease pressure at the same time as
you stimulate new growth.
Recommended
Varieties
Raspberries ‘Heritage’: Released by the New York
State Agricultural Experiment Station in Geneva, N.Y.,
in 1969, ‘Heritage’ is the world’s leading
primocane-fruiting raspberry cultivar. The red berries
are medium size on very productive and hardy canes. It
is one of the latest ripening primocane varieties, which
is good for Texas. Fairly disease resistant or tolerant,
it nonetheless does have some problems with mosaic virus
complex and aphids under high pressure. The canes can
reach seven feet in height, if left untipped. Tipping
will maintain a good picking height.
‘Fall Gold’:
Released in 1967 by E.M. Meador of the New Hampshire
Experiment Service, ‘Fall Gold’ bears yellow-gold fruit
on both primocanes and floricanes. The canes are
vigorous and sucker freely. Very hardy, it is considered
an ever-bearing variety. It is very similar to
‘Heritage’ in bearing time and vigor.
Blackberries
‘Prime Jim’: Because this variety has a higher chill
requirement than areas of Central and South Texas
receive, it is recommended only for North Texas. Not as
heat tolerant as ‘Prime Ark 45.’
‘Prime Jan’: Because
this variety has a higher chill requirement than areas
of Central and South Texas receive, it is recommended
only for North Texas. It is not as heat tolerant as
‘Prime Ark 45.’
‘Prime Ark 45’: A 2009 release from
the University of Arkansas, this blackberry seems to fit
the bill for most Texas growers. The berries are firmer
and larger than the two previous releases, resulting in
better shipping and storage qualities. It is more heat
tolerant that either ‘Prime Jim’ or ‘Prime Jan.’
In
2008 Jim Kamas, Extension Horticulturist with the
Department of Horticultural Sciences, Texas Cooperative
Extension in Fredericksburg, received several trial
blackberries from John R. Clark of the University of
Arkansas. They included two primocane-fruiting
blackberries labeled APF 77 and APF 45. In 2009, the
University of Arkansas released APF 45 as ‘Prime Ark
45.’ To date APF 77 has not been released, but it looks
good in the trial at Fredericksburg. Clark says that it
may be released in the future. ‘Prime Ark 45’ is a
winner and can stand our summer heat and bear well on
primocanes.
Culture Mowing or cutting of canes
is usually done in November just after the first hard
freeze. Cut at about two or three inches high, not
completely to the ground.
Mulching the beds after
they are cut is a good idea but not necessary in the
warmer parts of Texas. By adding mulch at this time you
will help suppress weeds and add organic matter to the
soil. Organic matter is essential for good raspberry
production and it is good for blackberries, though not
quite as essential.
Heavy clay or calcareous soils
are not good for raspberries. It is best to build raised
beds and add a sandy loam soil and lots of organic
matter if you have these types of soil. Blackberries
will tolerate heavy clay, but they must contain plenty
of organic matter and must be kept moist.
The best
soil for both of these berries is a loamy soil
containing organic matter.
Raspberries need a well
drained soil, but one that holds moisture. By adding
organic matter you can usually achieve the ability to
hold moisture without impeding drainage. Mulches such as
hay, leaves, bark, sawdust or commercially produced
mulches are good for the organic matter they contain. It
will take nearly a year to really get the mulches broken
down into the humus the plants need. So add some mulch
every year for continuing production.
Frequent
watering is necessary for good production. The ground
must be kept moist in the summertime to avoid stressing
the plants. During the late fall and winter just a
little water in dry periods, as necessary.
For
raspberries a little shade in the afternoon is
beneficial. Try planting on the east or northeast side
of some trees or a structure to avoid the afternoon heat
of summer. Some growers use shade structures over
raspberries. In contrast, blackberries need full sun.
A soil test should be done to determine soil nutrients
and any deficiencies should be corrected. As a general
rule, 30 to 70 pounds of actual nitrogen should be added
per acre each year, depending on row spacing of
established plants. For new plantings, an application of
10 pounds of actual nitrogen per acre about six weeks
after planting is usually sufficient to get the plants
off to a good start.
Raspberries can also be grown in
large containers such as the 7-to-10 gallon sizes. They
will fruit well in containers and can be put on a patio
or next to a house or outbuilding. It is best to use a
container drip system if attempting to grow in
containers as they do need regular moisture. Most
potting soils are good for container culture. Just add a
little perlite and mulch every year to keep the roots
aerated and fed.
Primocane-fruiting raspberries can
and are being grown in commercial greenhouses with
staggered fruiting times so that the growers have
year-round production. This practice is common in
Europe. ‘Heritage’ is the predominate variety in this
culture.
Richard Ashton is the author of several
books on fruit growing, including The Incredible
Pomegranate — Plant and Fruit; Jujube — The Chinese
Date; Sweet Cherries — For Southern Orchards and
Plums
of North America. They are all available from Third
Millennium Publishing on the internet at
www.3mpub.com/ashton.
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