Learn About Blackberries

How to Sow

  • Blackberries may be planted as bare root or potted plants.
  • Choose a well-drained, sunny location with no standing water. Prepare the soil before planting by mixing compost or other organic matter in with the soil. Work the soil deeply.
  • Space canes 3 feet apart in rows 6 feet apart. Dig each hole to twice the size of the root mass.
  • Plant blackberries 100 feet away from red raspberries.

Planting Bare Root Plants:

  • Before planting, trim very long or broken roots.
  • Cut back top growth to 6 inches.
  • Set roots 1-2 inches deeper than formerly grown.
  • Back fill with loose soil. Gently press soil in around the root ball. Transplants need good root-to-soil contact. Do not press too hard because that can cause soil compaction and root damage.
  • Gently water around the root ball to settle the soil and drive out air pockets.
  • After planting be sure to mark the plants with plant labels so you know where they are and what varieties they are.
  • Mulch with 2-3 inches of compost of pine needles to retain moisture and prohibit weed growth.

Planting Potted Plants:

  • Set the plant in the hole at the same depth as it was growing in the pot.
  • Backfill the hole and press firmly around the base of the planting.
  • Water deeply. The water will seal off any air pockets around the root ball.
  • After planting be sure to mark the plants with plant labels so you know where they are and what varieties they are. 
  • Mulch with 2-3 inches of compost of pine needles to retain moisture and prohibit weed growth.

How to Grow

  • Keep weeds under control during the growing season. Weeds compete with plants for water, space and nutrients. Control them by either cultivating often or use a mulch to prevent their seeds from germinating.
  • Add mulch each year as needed.
  • Keep plants well-watered during the growing season, especially during dry spells. Plants need about 1-2 inches of rain per week during the growing season. It's best to water with a drip or trickle system that delivers water at low pressure at the soil level. If you water with overhead sprinklers, water early in the day so the foliage has time to dry off before evening, to minimize disease problems. Keep the soil moist but not saturated.
  • In the spring, before leaves sprout, apply a granular fertilizer following the instructions on the label. Most new growth will come from the plant’s crown under the soil. Plants use a lot of energy in spring when growth begins, so do not let plants dry out.
  • Remove all wild brambles near cultivated varieties to prevent virus diseases.
  • Each year cut to the ground all but 5 or 6 of the most vigorous canes of each plant about 6 inches apart to improve fruit production. Prune these to about 30 inches to encourage lateral branches. They will bear fruit the following year, and should be cut to the ground after harvest.
  • Repeat these steps each year:
    • Select the most vigorous canes
    • Cut them back to 30 inches
    • Prune back the previous year’s laterals
    • Remove canes after laterals have borne fruit
  • NOTE: For Primocane Bearing Blackberries: These bear fruit twice on the same cane. Prune new shoots each year as for standard blackberries. New shoots bear fruit at the tips in fall, and further down on the cane the following spring. Cut back old canes after the second crop is harvested.
  • Remove and destroy old canes immediately; rake up and remove fallen leaves and fruit to help prevent fungus diseases. Check with your local Cooperative Extension Service for pest controls recommended for your area.
  • Blackberries may not need support when they are properly pruned. To prevent wind damage and to make harvesting easier, canes may be individually tied to two parallel wires strung between posts at either end of the row. 

Growing tips

  • Fruiting season is in summer: July, August or September. Fruit will not continue to ripen after picking so be sure to wait until fruit is ripe before picking. The fruit will ripen from red to black, but do not pick them as soon as they turn black, wait 3-4 days and pick when the color has a dull appearance. These will be the sweetest fruit. Pick in the morning or evening, when temperatures are coolest.
  • Expect to harvest at least twice a week for several weeks.
  • Fruit damages easily so handle with care. Store in a shallow container in the fridge as soon as possible after picking.
  • Wash blackberries and allow them to dry on a clean paper towel for 10-20 minutes before storing.
  • Fresh blackberries last a day or so, but can be frozen or used for preserves.

Common Pests and Problems

Common Disease Problems

Anthracnose: This fungus causes spots on the canes with purple margins that can spread and cover the stem. Spots may appear on young leaves that are yellow with purple margins, and may cause holes in the leaves. Canes and stems may die back. Burpee Recommends: Remove and destroy infected canes and any leaf debris.

Crown Gall: Rough, wart-like growths or galls appear on the crown at or just below the soil surface. These can also form on the stems or canes of blackberries. Plants can become stunted, subject to drought stress and wind damage. Large enough galls may cause girdling which results in plant death. Burpee Recommends: Examine the canes prior to planting for any indication of galls. Avoid injury of the plant. You can remove the gall if it is small enough by cutting around it into healthy wood allowing that area to dry out, cutting into healthy tissue as little as possible. If plant is severely infected, remove it.

Orange Rust: This fungus causes plants to become stunted and weak with poor fruit production. Shortly after new growth appears in spring new shoots are weak and spindly, leaves are pale green to yellow. In a few weeks lower leaf surfaces are covered in bright orange powdery spores. Affected leaves wither and die by early summer. The disease is systemic, and remains throughout the plant so just removing infected leaves will not improve the health of the plant. Burpee Recommends: Dig up and remove infected plants and destroy nearby wild brambles. Remove plants before the spores are discharged if possible.

Phytophthora Root Rot: This soil borne disease thrives in poorly drained soils and can live in the soil for years. Above ground symptoms include pale or reddish leaves, small leaves, defoliation, branch die back, stunting and death. Burpee Recommends: Remove infected plants.

Powdery Mildew occurs on the top of the leaves in humid weather conditions. The leaves appear to have a whitish or greyish surface and may curl. Burpee Recommends:  Avoid powdery mildew by providing good air circulation for the plants by good spacing and pruning. Contact your Cooperative Extension Service for fungicide recommendations.

Common Pest and Cultural Problems

Aphids: Greenish, red, black or peach colored sucking insects can spread disease as they feed on the undersides of leaves. They leave a sticky residue on foliage that attracts ants. Burpee Recommends: Introduce or attract natural predators into your garden such as lady beetles and wasps who feed on aphids. You can also wash them off with a strong spray, or use an insecticidal soap.

Japanese Beetles: Burpee Recommends: Hand pick early in the morning into a bucket of soapy water.

Borers: Larvae are worms with whitish bodies with brown heads about 1 inch long. The adults are clear-winged moths with black and yellow bands on their bodies. The larvae tunnel in canes and cause lateral growth to wither and canes to die. Burpee Recommends: Prune and destroy infested canes.

Leafhoppers: These appear in varying shades of green, yellow and brown, are very active and slender and wedge shaped. They can leave foliage pale and curled and leave secretions on the plants and fruit. They can spread disease. Burpee Recommends: Try insecticidal soaps. Contact your Cooperative Extension Service for control assistance.

Spider Mites: These tiny spider-like pests are about the size of a grain of pepper. They may be red, black, brown or yellow. They suck on the plant juices removing chlorophyll and injecting toxins which cause white dots on the foliage. There is often webbing visible on the plant. They cause the foliage to turn yellow and become dry and stippled. They multiply quickly and thrive in dry conditions. Burpee Recommends: Spider mites may be controlled with a forceful spray every other day. Try hot pepper wax or insecticidal soap. Check with your Cooperative Extension Service for miticide recommendations.

FAQ

Are there seedless blackberries? Sorry, not yet!

Do I need two different varieties to get fruit?  No, blackberries are self-fruitful.

Will I get fruit the first year?  Expect fruit two years after planting. If you choose a primocane variety you may get some fruit the first fall after planting in spring.

How many harvests a year will I get? One unless you are growing a primocane-bearing blackberry. Primocane types produce two crops.

How far from red raspberries should I plant my blackberries?  Plant at least 100 feet apart to avoid disease issues.

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