By Brent Rodgers and Bev Thierwechter
Piedmont Master Gardeners
Blackberries and raspberries are favorite berries of home gardeners. They are delicious, high in fiber, low in calories and fat, and rich in vitamins. Relatively easy to grow in temperate climates like Virginia, they produce more and take less space than many other fruits. They bear fruit after only one to two years and can continue producing for 10 years or longer. Growing your own means enjoying freshly picked berries with less spoilage, but success depends on care in planting and maintaining your plants.
Known as caneberries or brambles, blackberries and raspberries produce fruits on canes emerging from the plant’s crown, a compressed stem located at or just below the soil level, where the roots and above-ground canes meet. Raspberries can also produce canes from roots, but blackberry canes only grow from crowns.
The crowns and roots are perennial (living for many growing seasons) but the canes are biennial (having a two-year life cycle). The first-year shoots are called primocanes, and the second-year shoots are called floricanes.
There are two fruiting types of blackberries and raspberries. Primocane fruiting varieties bear fruit on the first-year shoots in late summer and then again on the second-year canes the following summer after a period of winter chilling and appropriate pruning. Because they produce a crop on both first year and second year growth, they are also known as “ever bearing.” Floricane fruiting varieties bear fruit only on second-year canes, and then those canes die.
New canes grow from the crown every year, so after the year when planted, crowns will produce both primocanes and floricanes and fruit according to their fruiting type.
Selecting the Plants
Consider the fruiting type, growing habit (trailing, semi-erect or erect), presence or absence of thorns and, in the case of raspberries, the fruit color (red, black, purple or yellow). The characteristics of the plants selected will have an impact on both planting and maintenance.
Choose certified, high quality, disease resistant, one-year-old plants of the best varieties for your USDA plant hardiness zone. Blackberries generally prefer the cooler regions of Virginia, and raspberries prefer the warmer regions.
Planning the Space
After choosing your plants, look at the whole home landscape to: 1) create a rough plan, thinking about the amount of space available; 2) select a sunny site on level ground with good drainage and protection from strong winds; 3) start small and add more plants as time and skill allow; 4) plan the size of your berry patch based on the recommended distance between plants in rows and between rows; 5) decide whether to trellis or otherwise support the plants, which can affect the space required; 6) consider a hedge row format as a habitat for wildlife and beneficial insects; 7) do a soil test in advance and follow recommendations on adjusting the pH and other nutrient levels.
Be sure to take into account the estimated yield of the crop. Blackberries can produce 5 to 15 pounds per plant and raspberries 3 to 5 pounds per plant.
Preparing and Maintaining
the Berry Patch
Soils: These berries do best in well-drained, sandy loam soils with a pH between 6.0 and 6.5 and 3 percent or more organic matter. The availability of plant nutrients depends on the pH level and may need to be adjusted depending on the soil test results.
Time to Plant: Plant the crowns in late fall or early spring about four weeks before the average date of the last frost. Set the crowns in at or slightly below the soil surface. Some plants come with a “handle”, a piece of old cane, which can be used to set the plants in place and cut off after new growth begins.
Maintenance and Mulch: Four to six inches of hardwood or leaf mulch should be applied after planting and replenished as needed. Plants need 1 to 2 inches of water per week during the growing season.
Fertilization: At the time of planting, no fertilizer is necessary. Instead, promote soil fertility with the addition of compost and mulch. Fertilizer should be added if the soil test indicates amendments are necessary and should be applied according to the fertilizer’s label. Usually about a half-pound of nitrate of soda or three-fourths of a pound of 10-10-10 for each 100 square feet of mulched area will be enough. Overfertilization damages plants and causes runoff that pollutes our waterways and adversely affects wildlife.
Support: Blackberries and black and purple raspberries should be trellised, trained along a fence, staked or otherwise supported. Red raspberries have many suckers, so they are often grown in hedgerows.
Pruning: Prune dead or damaged canes in late winter after severe cold is past and before buds begin to swell. Prune in summer to stimulate lateral branching. Keep primocane and floricane fruiting varieties separate, since different pruning techniques apply. (For detailed pruning guidance, see publication SP-284 at https://utextension.tennessee.edu/).
Disease and Pest Management: For recommendations on specific disease and pest problems with caneberries in Virginia, refer to the Virginia Cooperative Extension 2021 Pest Management Guide for Home Grounds and Animals (publication ENTO-397 at https://ext.vt.edu/).
Interplanting Blackberries and Raspberries
Planting blackberries and raspberries in the same row or close by can increase the risk of plant disease and damage. A better option is to plant blackberries and raspberries in different locations. Penn State’s “The Mid-Atlantic Berry Guide for Commercial Growers” offers this advice: “Keep black and purple raspberries away from old plantings of red raspberries because mosaic virus can spread from red raspberries and is more severe on black and purple raspberries; keep all red raspberries away from old plantings of blackberries because blackberries can be a symptomless carrier of curl virus.” Removing wild brambles in the vicinity may also keep disease pressure down.
Take care of those berry plants and enjoy “the fruits” of your labors!