Growing Raspberries
in Montana Gardens
by Cheryl Moore-Gough, Extension Horticulture Specialist and Dara Palmer,
Montana Master Gardener Coordinator
Just about everything the home gardener might want to know about growing
raspberries is explained in this MontGuide: differences among cultivars, how
to choose a good site, preparing the ground, planting, pruning and training,
fertilizing and irrigating. It also touches on insects and diseases.
RASPBERRIES WILL GROW BEST BELOW 7000 FEET
in elevation in full sun on neutral or slightly acid (pH 7
to 6), well-drained loam soils. Soils with higher pH can
be decient in available iron, resulting in raspberry leaves
becoming chlorotic (turning yellow). e canes are subject
to rapid desiccation and breakage, particularly in winter,
and benet from a windbreak.
Of the four color classes (red, yellow, black and purple)
and two bearing habits (June bearing and everbearing, also
called fall bearing), June bearing red raspberries are most
common in Montana and they
are among the hardiest. Most
yellows are color mutations of
the reds and can also be quite
hardy. Black raspberries are
the least hardy raspberries,
but there are promising new
black varieties that are hardier.
Purple raspberries are hybrids
of the black and the red and
are intermediate in hardiness.
ey have a strong avor that is
preferred for cooking purposes,
but they are not highly popular
otherwise. Most gardeners plant
June bearing types since the growing season is often not long
enough for everbearing plants to mature a fall crop. Gardeners
in the warmer areas of the state may be successful with black
and purple raspberries and with everbearing types. Cultivars
recommended for Montana with their descriptions appear
in Table 1 on page 2.
Growing Raspberries
Site Selection
Gently sloping sites protect the plants from some types of
cold injury by allowing colder air to drain down-slope, away
from the plants. Always plant on the slope and never at the
top of the hill, where wind damage is most severe, or at the
bottom, which becomes a cold air pocket.
Raspberries need plenty of moisture but do poorly
in wet soils. Be sure the subsoil is well-drained with no
hardpan or berm to restrict water drainage. e water table
should be at least six feet deep at its highest point (usually
in spring). Flooding for as little as 24 hours can suocate
raspberry roots and wet sites can encourage crown gall and
root rot diseases.
Cultivated raspberries can contract several diseases
from wild relatives. To reduce
disease incidence, select a site
at least 300 feet from other
cultivated or wild brambles.
Also, raspberries have root
rot diseases in common with
tomato, potato, eggplant,
peppers and petunias, so keep
the plantings separated by some
distance and never follow one
of these crops with raspberries.
Preparing the ground
Land that has been previously
cultivated produces the best
crops. If it was previously sodded or old pasture, turn it at
least one year prior to planting raspberries and continue
to cultivate it to allow the organic material to decompose
and to bring weeds under control before planting. If weeds
continue to be a problem, cover the planting area for several
months with black plastic to smother seedlings.
All small fruit crops benet from additional soil organic
matter. Before planting, turn under about 1200 pounds (40
bushels) of rotted manure or compost per 1000 square feet
of planting area. Apply about 6 ounces of super phosphate
(0–20–0) per bushel of manure to boost soil phosphorus levels.
eviewNA/19
PHOTO BY FRANK ERICKSON
MontGuide
For More Online MontGuides, Visit www.msuextension.org
YARD AND GARDEN MT199804AG Revised 11/19
Planting
Obtain certied disease-free plants from a reputable nursery.
Local dealers are often the best source of plants. Old raspberry
patches are often infected with numerous diseases; transplanting
from them is risky and not worth the few dollars that can
be saved on plant material.
Plant dormant raspberry plants as soon as the ground
can be worked in early spring or in mid-fall after plants have
lost their leaves.
e site will ideally have well-drained soil with a pH
of between 5.5 and 6.5. Set potted plants as deeply as they
grew in the nursery, spaced about 2 feet apart in rows spaced
5 feet apart. Set bareroot plants in a shallow hole wide enough
to accommodate the roots. Spread the roots out so that the
crown (where the roots meet the stem) is 1 – 2 inches below
the ground surface.
Cover with soil and rm in to remove air pockets.
Water well and cut canes back to six inches above the ground.
Newly planted canes will not produce fruit the rst
year, and typically not the second, but will provide a crop in
the third year. Cultivate regularly to control weeds.
Plants of red and yellow raspberries will sucker and grow
into a bed about 3 to 4 feet wide. Maintain this width by
careful pruning since wider rows make it dicult to harvest
fruit from inside plants. Black and purple raspberries do not
sucker like the reds and are maintained in individual hills.
Pruning
Raspberries need regular pruning to keep the planting
productive. How to prune them depends upon the type of
raspberries being grown. Raspberries produce two types of
canes, primocanes are vegetative while owering canes are
called oricanes.
June bearing red and yellow cultivars produce primocanes
the rst season. ese canes cease shoot growth in late summer
and form ower buds from their tips to their bases. ese
buds bloom and fruit the following spring as oricanes. Canes
TABLE 1. Characteristics of Raspberry Cultivars
Variety Zones Thorns Color Susceptible Resistance
June/Summer Bearing Types
Amira 4 to 8 Red
Boyne 3 to 8 Red LLR, PRR, CG
Bristol 4 to 8 Black RFB PDM
Canby 3 to 8 Thornless Red A Viruses, Aphids
Encore 4 to 7 Red PRR, Cold, PDM Cold
Festival 3 to 8 Few Red PRR
Killarney 3 to 8 Red LLR PRR
Latham 3 to 8 Red Mildew Disease
Mammoth 4 to 8 Thornless Red
Nova 3 to 8 Few Red
Rust, Cane
Diseases, Heat
Prelude 4 to 8 Red PRR, Cold
Fall/Everbearing Types
Anne 4 to 7 Yellow Leafhoppers, Rust PRR
Autumn Bliss 3 to 8 Thorny Red RBDV
Autumn Britten 3 to 8 Red
Caroline 4 to 7 Red
PRR, Yellow Rust,
Gray Mold
Fall Gold 4 to 8 Yellow
Heritage 4 to 8 Thorny Red
Disease, Heat,
Humidity, PDM
Himbo Top 4 to 8 Red PRR
Jewel 4 to 8 Black A
Joan J 4 to 8 Thornless Red
Polana 3 to 8 Red
Royalty 4 to 8 Thorny Reddish-Purple CG RA, RMV
Disease Codes:
A = Anthracnose
CG = Crown Gall
LLR = Late Leaf Rust
PDM = Powdery Mildew
PRR = Phytopthora Root Rot
RA = Raspberry Aphid
RBDV = Raspberry Bushy
Dwarf Virus
RFB = Raspberry Fireblight
RMV = Raspberry Mosaic Virus
SWD = Spotted Wing Drosophila
2
fruit only once and die soon after harvest. While they are
fruiting, new primocanes grow from the base of plants and
form buds for next year’s crop.
During spring pruning remove all dead, damaged
and weak canes (Figure 1A). in the remaining canes to
stand about 6 inches apart in the row. Let the row width
slowly increase to about 3 to 4 feet so that the row becomes
a “bed.” Harvesting from the middle of a bed wider than
4 feet is dicult.
Everbearing red and yellow cultivars grow similarly to
the June bearing types but produce two crops each season.
Vegetative canes grow the rst season and set their ower buds
in early fall like the June bearing types. Buds on the lower
parts of the canes remain dormant but buds on the upper 6
to 10 inches of cane bloom immediately, producing the fall
crop at the tips of current season’s wood. is portion of the
cane dies after fruiting, but the lower portion overwinters,
and its buds produce the rst crop the following year. So,
the rst crop of the season is produced on the lower parts
of one-year-old canes and the second crop of the season is
produced on the upper parts of current season canes. After
fruiting, the remaining part of the cane dies and is removed
during spring pruning. in everbearing plants as you would
June bearing plants.
June bearing black and purple raspberries are pruned
somewhat dierently than red and yellow cultivars because
of their different growth habits. In mid-summer, pinch
the tips of the current season’s canes to about 30 to 36
inches in height. This is called “summer topping” and
it forces formation of strong lateral shoots. ese shoots
cease their growth in late summer and form ower buds
for next year’s crop at that time. During spring pruning,
remove all old fruited canes from the previous season and
shorten the laterals on new canes to about 16 inches in height
(Figure 1B). These will form fruit in summer then the
entire cane will die, to be removed the following spring and
replaced by new canes growing from the crown.
Training
Common red raspberry cultivars grow erect but sometimes
droop into the aisles making harvest dicult. Unsupported
canes are also prone to damage from the wind. To make a
trellis, sink two strong posts into the ground 8 feet apart
and attach a cross piece 30 inches long to each post about
40 inches above the ground (Figure 2). Fasten a strand of
fence wire to each of the two ends of one crosspiece and run
them the length of the row, fastening them to the cross piece
on the opposite post. Train the canes to grow up between
the wires to keep them from drooping too far out of the
row. Loosen one end of each wire at the end of the season
to prevent the wires from contracting in winter and pulling
the posts out of the ground.
An alternative support is to tie several canes to a strong
stake; remove the tie during pruning (Figure 3).
Figure 1A. Red and yellow raspberry plants before (left) and after
(right) pruning.
Figure 1B. Black or purple raspberry plants before (left) and after
(right) spring pruning. Note that the laterals have been shortened for
best plant productivity.
Figure 2. Red and yellow raspberries supported by a simple trellis.
Figure 3. Several canes of red
and yellow raspberries can be
supported by a single stake.
3
Fertilizer
Raspberries need ample amounts of the major nutrients to
produce good crops, since larger diameter canes yield more
fruit. Broadcast a complete fertilizer such as 10–10–10, or
another fertilizer with equivalent nitrogen, to the patch
early each spring at the rate of about 6 to 8 pounds per 100
linear feet of row. If an organic fertilizer is preferred, be sure
to apply it at rates equivalent to those given above. Do not
fertilize later than mid-June.
Iron deciency can be a problem in much of Montana.
ough the soil may contain enough iron, the compound
is chemically bound and unavailable for plant use. Iron
deciency symptoms appear as normal-sized yellow leaves on
oricanes (Figure 4). Often, the midvein and lateral veins
remain green while the tissue between the veins yellows. If
this appears, apply an organic mulch and use an acid fertilizer
such as ammonium sulfate to reduce the alkalinity. If the
problem persists apply chelated iron according to directions
on the label.
Irrigation
Irrigated plants are usually more vigorous and productive
than those not irrigated. Begin seasonal irrigation when
irrigation begins in the vegetable garden and apply about 1
to 2 inches of water every week through harvest. Adjust to
provide more water, up to perhaps 2 to 2.5 inches per week,
during hot, windy weather. Adequate moisture will keep the
soil moist (not soaked) to a depth of 10 to 12 inches, where
70 percent of the raspberry root system is located. Irrigate
the soil, not the foliage or fruit as wet fruit will rot rapidly
before harvest.
Supplying adequate water is particularly critical during
bloom and fruit formation. Inadequate amounts at these times
can cause poor fruit set, malformed fruit, and crumbly fruit.
Decrease or eliminate irrigation between the end of
harvest and autumn leaf fall to allow the canes to harden
for winter. After leaf fall and before the soil freezes, supply
the plants with 1 inch of water per week to ll their internal
water reserves and decrease the amount of damage from
winter desiccation.
Harvest and Storage
Raspberries are the most delicate of any small fruit. Ripe
fruit can deteriorate in a few hours if weather is hot and
humid. Select raspberries which are bright-red (red raspberry)
or fully-colored (black, purple, or yellow raspberry). Ripe
raspberries should be bright, shiny, uniform in color and
maturity. Avoid overly soft fruit with dark spots or if wet or
moldy. A good test for ripeness is how easy the berry pulls
from the cane. A truly ripe berry will slip o the stem with
a gentle pull. Harvest the fruit early in the morning and
cool it immediately to protect quality.
Place berries loosely in a shallow container to allow
air circulation. Holding raspberries in containers larger
than a half pint will result in the fruit on the bottom being
crushed by the weight of the fruit above it. Berries are highly
perishable. Store immediately in a cool, moist area of the
refrigerator, such as in the vegetable keeper to help extend
the usable life of the fruit. Do not wash until ready to eat.
Raspberries can typically be stored one to two days in the
refrigerator.
Winter Damage
Late fall watering as described in the “Irrigation” section
will help reduce the incidence of winter drying, especially
in the tips of the canes.
Raspberry canes will de-harden and can become active
in late fall and mid- to late winter if the air temperature
remains above about 41°F for several days. e sudden hard
freezes that usually follow kill the active tissue. Because the
upper parts of the cane break dormancy rst they are the
most susceptible to this type of injury. Winter-damaged
canes often produce undersized yellow leaves and small fruit.
Later in the summer these leaves become “bleached.” Reduce
the chances of this happening by wrapping the canes with
burlap (if there are only a few) or by building a temporary
fence to shade and cool the plants. is keeps the canes
Figure 4. Iron deciency shown on blueberry leaves. BY JOHN HARTMAN,
UNIVERSITY OF KENTUCKY, BUGWOOD.ORG 5407854
4
cold and the soil around them frozen, both of which reduce
injury. Remove the burlap plant wraps and the fence by late
March or early April.
Pest Control
Insects
Aphids and mites. ese common insects seldom need to
be controlled with anything but a hard spray of water. Wasps
will be attracted to overripe fruit, so harvest frequently.
Japanese beetles. is relative newcomer to Montana is
a distinctive, green and bronze beetle with a row of white tufts
on each side (Figure 5). ey can quickly skeletonize raspberry
leaves. See the MontGuide Japanese Beetle (MT201404AG).
Hand pick the adults and destroy.
Spotted-wing Drosophila (SWD). Another relative
newcomer to Montana typically appears in late July or August,
making these insects more problematic to late-bearing cultivars.
e female fruit y inserts eggs into soft-skinned fruits where
the immature ies develop (Figure 6). Monitor for their
presence using purchased or homemade bait traps consisting of
a lure, such as apple cider, and yellow sticky traps available at
the hardware store, in a plastic cup with small holes (Figure 7).
Figure 5. Japanese Beetles. BY GERALD HOLMES, CALIFORNIA POLYTECHNIC STATE
UNIVERSITY AT SAN LUIS OBISPO, BUGWOOD.ORG 1576852
Figure 6. SWD adult (top) and immature y in fruit (bottom).
BY HANNAH BURRACK, NORTH CAROLINA STATE UNIVERSITY, BUGWOOD.ORG 5444193 (TOP)
AND 5444186 (BOTTOM)
5
Figure 7. Homemade bait trap. BY HANNAH BURRACK, NORTH CAROLINA STATE
UNIVERSITY, BUGWOOD.ORG 5444190
Diseases
Remember that oricanes die immediately after fruiting,
so yellowing leaves on them is normal. Yellow leaves on
primocanes, however, can indicate an issue. in and prune
properly to avoid many diseases, and control weeds.
Gray mold will cause berries on the plant to rot
and be covered with a gray mold (Figure 8). Cool, moist
weather is conducive to this disease. Weed and prune well
to increase air circulation. If mold is present and you are
using a mulch, be sure to remove it at the end of the season
to avoid contamination the following year.
Root rots can be caused by several dierent fungi
(Figure 9). Excessive moisture in the soil can increase the
possibility of root rots and cane death due to lack of air in
the soil (Figure 10).
Animals
Rabbits will eat canes to the ground in winter. If they are
present in your location, exclude them with a chicken
wire fence.
Weeds
Weeds can harbor pests and diseases, and compete with the
raspberry canes for water, nutrients and sometimes sunlight.
Home gardeners control weeds by careful hoeing. A 4-inch
layer of organic mulch controls many weeds and keeps the
soil frozen in winter, reducing the incidence of plant heaving.
Clean straw, wood chips, sawdust or leaves insulate the
roots from extreme cold and conserve soil moisture as well.
However, rodents sometimes burrow through the mulch
in winter and damage the raspberry canes. Unfortunately,
this often happens under the snow and is not discovered
until spring thaw.
Abiotic Problems
Abiotic problems are those not caused by a living pathogen or
animal. ey are also called physiological diseases because they
arise following an alteration of the physiology of the plants.
Table 2 on page 7 lists symptoms and some possible causes.
Acknowledgements
e authors would like to acknowledge the original author
of this MontGuide, Dr. Bob Gough, former Extension
Horticulture Specialist.
Figure 8. Gray mold caused by Rhizopus (left) and Botrytis (right).
BY JOHN HARTMAN, UNIVERSITY OF KENTUCKY, BUGWOOD.ORG 5407874
Figure 9. Phytopthora root rot. BY CHRISTER OLSSON, SWEDISH BOARD OF
AGRICULTURE, BUGWOOD.ORG UGA0725005
Figure 10. Sudden wilting of primocanes caused by Phytopthora
root rot. BY ANDRÉ BOLAY, ST. FÉDÉR. DE RECHERCHES AGRONOMIQUES DE CHANGINS,
BUGWOOD.ORG UGA0725043
6
TABLE 2. Abiotic Problems of Raspberries
Plant part affected Possible cause
Canes
Death of whole cane or individual buds before spring leaf out Low temperature
Sudden death after leang out Low temperature damage to vascular tissue
Breakage, abrasion, desiccation Wind
Wilt Excessive heat, drought, or wind
Fruit
Brown, dry High sunlight or high temperature
Crumbly Drought
Off-colored, white
(Figure 11)
Sunscald, high UV exposure
Leaves
Torn, shredded; no insects apparent Wind, hail
Figure 11. Sunscald damage on raspberry fruit. BY WHITNEY CRANSHAW, COLORADO STATE UNIVERSITY, BUGWOOD.ORG 5445297 (LEFT) AND 5445295 (RIGHT)
7
Figure 12. Harvest fruit early in the morning and cool immediately to
protect quality. BY MSU EXTENSION
Figure 13. Rinse raspberries before consuming. Do not rinse berries
until ready to eat. BY MSU EXTENSION
File under: Yard and Garden
(Fruit)
Reviewed November 2019
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