Extension Agent, Horticulture
Raspberries can be used in a variety of appealing ways. Freshly prepared and sugared raspberries are excellent when served alone or used to make a raspberry sundae. The fruit can also be used to make delicious jams, jellies, pies, and other desserts. Besides their excellent flavor, raspberries are a nutritious food, contributing vitamins A and C and various minerals to the diet. In addition, raspberries contain a natural substance called ellagic acid, which is an anti-carcinogenic (cancer-preventing) compound.
Raspberries ripen shortly after strawberries and make an excellent small fruit crop for summer and fall depending on the cultivars selected. Two years are required to establish a raspberry planting, but once established, the planting can remain productive for several years if given good care.
Raspberries may be classified by fruit color and/or fruiting habit. They may be red, black, purple, or yellow-fruited types. The black raspberry is most popular in Ohio. The red type is the second most popular type. The red raspberry is first to ripen, followed by the black, purple, and yellow cultivars. Compared with black raspberries, red raspberries tend to be more cold hardy, have larger berries, and have more erect canes. Black raspberries are less cold hardy; have smaller, seedier, and more aromatic berries; and have arching canes. Purple raspberries are hybrids of red and black raspberries and tend to respond in growth habit similar to black raspberries. Most yellow raspberries are similar to red raspberries in growth habit.
Raspberries may also be classified as summerbearing or everbearing. Summerbearing cultivars produce one crop in the early summer, while everbearing cultivars can produce up to two crops a year, one crop being produced in the spring and the second crop in the fall. Most everbearing raspberries are of red or yellow type. Cultivars recommended for planting in Ohio gardens are listed in Table 1.
|Table 1. Recommended Raspberries and Their Cultural Characteristics|
|Fruiting Habit||Cultivar||Fruit Color||Ripening Season||Cultural Characteristics|
|Summerbearing||Allen||Black||Early to mid-season||Large and attractive fruits with mild
flavor. Plants are vigorous and productive. |
Medium to large fruits with good quality and flavor. Plants are vigorous, productive, and resistant to anthracnose.
Fruits are medium sized with good flavor. Plants are vigorous and productive. It is for trial in Ohio.
The leading cultivar and producer in Ohio. Large, glossy, and firm fruits with good quality. Hardy, vigorous, and productive.
|Black Hawk||Black||Late season|
|Liberty||Red||Mid-season||Medium sized fruit with good flavor and freezing quality.
Small fruit with good color and fair flavor. Moderately productive. Vary cold hardy.
Medium sized fruit with good flavor. Moderately productive. Cold hardy.
Medium to large sized fruit with good flavor. Plants are vigorous and high yielding.
Bright red, firm, and medium sized fruits with good flavor. Productive with fair hardiness.
reddish, and tart fruits that are good for jams and jellies. More
vigorous and productive than most black raspberries.|
Large, and reddish fruits that are sweet and flavorful when eaten fresh. Vigorous and extremely productive.
|Everbearing||Heritage||Red||Late||Medium sized fruits with good color and
flavor, firmness, and freezing quality. High yielding.|
Large and soft fruits with good flavor. Moderately productive.
|Fall Gold||Yellow||Early||Medium sized and soft fruits with excellent flavor. Moderately yielding. For trial only.|
|All the above cultivars are self-fruitful and can produce crops without cross pollination. It is also helpful to visit extension agents or local raspberry growers for information about cultivars that are good for your local area.|
Raspberries will grow and produce on many different types of soil but will be most productive on sandy loam soils well supplied with organic matter and plant nutrients. The soil should be well drained and have a pH between 5.8 and 6.5. Plant raspberry bushes on ridges or in raised beds if drainage is a problem.
Raspberries should be planted in an open site that receives at least 6 to 8 hours of sunlight. Avoid planting raspberries within 300 feet of any wild blackberry or wild raspberry plants and in areas where tomatoes, potatoes, or eggplants have been grown previously. Early spring planting is preferred over fall planting. Plant as soon as the soil can be properly prepared. The plants can be established either in hedgerows or using the hill system depending on the types of raspberries (Table 2). Also refer to Table 2 for recommended training systems and spacing. Planting too closely results in undesirable competition, while planting too far apart wastes space.
|Table 2. Training Systems and Plant Spacing for Raspberries*|
|Type of Raspberries||Training System||Plant Spacing in the Rows||Spacing between Rows|
|Red, yellow Raspberry||Hedgerow, low trellis||2 Feet||10 Feet|
|Black Raspberry||Hill, low trellis||2.5 Feet||10 Feet|
|Erect Raspberry||Hill, no trellis||3 Feet||12 Feet|
|Purple Raspberry||Hill, no trellis||3 Feet||12 Feet|
|Thornless Raspberry||Hill, high trellis||6 Feet||12 Feet|
|*Spacing between rows should be increased for fertile soils.|
The raspberry must be kept free of weeds, watered when necessary, fertilized, pruned regularly, kept free of insect and disease pests, and in some cases, supported with a trellis.
Mechanical removal of weeds is highly recommended. A mulch of straw, sawdust, or other appropriate material can be very helpful for weed control, and soil moisture conservation in the raspberry plantings where soil drains well. If soils are too heavy in texture and retain too much moisture, it may not be good to mulch raspberry plants. Mulching can worsen phytophthora root rot and/or verticillium wilt in raspberries planted in poorly drained soils.
Fertilizer or lime applications are best made following the recommendations based on the soil testing results. Forms, sample bags, and instructions for soil testing can be obtained from your local Extension office. Soil fertility should be maintained by two applications of one pound of a 10-10-10 fertilizer or the equivalent per 100 feet of row at 10 and 40 days after planting. For the years after planting, raspberry plants need to be fertilized twice a year. The fertilizer should be broadcast in the row area once in the spring before growth begins in March, and one more time in May. Apply 2 to 3 pounds of a 10-10-10 fertilizer per 100 feet of row in each application.
It is very important to understand the terms used to describe various parts of a raspberry plant before attempting to prune raspberries (Figure 1). Raspberry canes are of two types, primocanes and floricanes. Primocanes are first year canes while floricanes are second-year fruiting canes.
Summer red raspberries should be pruned twice a year, first in the spring and immediately after harvest (Figure 2). The spring pruning, in late March or early April, consists of removing all weak canes and cutting back tall canes (over 5 feet) to 4.5 to 5 feet. The second pruning consists of the removal of canes that produced fruits, right after harvest.
Everbearing red raspberries such as "Heritage" raspberry can be pruned to produce fruit once a year or twice a year. If you follow the pruning methods used for summer red raspberries, "Heritage" raspberry will produce fruit once in spring and once in fall. However, many home gardeners and commercial growers mow or cut all "Heritage" canes to the ground in early spring (March or April) for the sake of simplicity. "Heritage" raspberry pruned this way will produce only one crop starting in early August in southern Ohio, and mid-August in central Ohio.
Black and purple raspberries are pruned three times a year: in the spring, summer, and after fruiting (Figure 3). First pruning is done in spring when lateral branches are cut back to 8 to 10 inches in length in mid-March. Second pruning is called tipping or heading of new canes or primocanes. When grown without supports, summer tipping is done when black raspberry canes reach 24 inches in height and when purple types reach 30 inches. Tipping is done by removing the top 2 to 3 inches of new shoots as they develop. Third pruning involves the removal of canes that produced fruits, right after the harvest.
The principal insects of raspberries are the raspberry cane borer, raspberry fruitworm, red-necked cane borer, and Japanese beetle. The common diseases on raspberries are mosaic virus, orange rust, anthracnose, cane blight, spur blight, crown or cane gall, and verticillium wilt. For additional information about growing raspberries, you may purchase Bulletin 591, Growing and Using Fruit at Home; Bulletin 783, Brambles, Production, Management and Marketing; and Bulletin 780, Controlling Diseases and Insects in Home Fruit Plantings from your local Extension office.
A trellis can help make the crop easier to manage and keep the canes off the ground so that berries are cleaner and easier to pick. A trellis can be constructed with posts at 15 to 20 foot intervals with cross arms to support wires placed 24 to 28 inches apart (Figure 4). The wires should be about 36 inches high for red raspberries and 40 inches high for the black and purple types.
Welty, C., R. C. Funt, R. N. Williams, T. Wall, and M. Ellis. 1998. Ohio Commercial Small Fruit and Grape Spray Guide. Bulletin 506B2. Columbus: Ohio State University Extension.
Funt, R. C., S. Bartels, H. Bartholomew, M. Ellis, S. T. Nameth, R. L. Overmyer, H. Schneider, W. J. Twarogowski, and R. N. Williams. 1998. Brambles: Production, Management, and Marketing. Bulletin 436. Columbus: Ohio State University Extension.
Pritts, M., and D. Handley. 1989. Bramble Production Guide. Ithaca, NY: Northeast Regional Agricultural Engineering Service.
Utzinger, J. D., R. C. Funt, M. Ellis, and R. L. Miller. 1986. Growing and Using Fruit at Home. Bulletin 591. Columbus: Ohio State University Extension.
Ellis, M. A., and C. Welty. 1998. Controlling Disease and Insects in Home Fruit Plantings. Bulletin 780. Columbus: Ohio State University Extension.
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Keith L. Smith, Associate Vice President for Ag. Adm. and Director, OSU Extension.
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