Blackberry Agronomy Guide
Description
Blackberry has become a popular fruit with both consumers and growers. The erect to semi-erect plants are available in either thorny or thornless cultivars. Floricane-fruiting cultivars ripen in June and July, and the recently developed primocane-fruiting cultivars have the potential to extend the berry harvest season into September. The delicious berries are enjoyed as fresh fruit and can be processed into pies, muffins, jams, sauces, juice, wine or other products.
Site Selection
Blackberry is tolerant of a wide range of soil types, but performs best on soils that are slightly acidic and moderately fertile, have adequate organic matter content, and have good surface and internal water drainage. To reduce the risk of damage from spring frost, select sites that are elevated relative to the surrounding land. Blackberry requires full sun for optimum production.
Fertility
Soil test before planting, and adjust soil levels of phosphorus to 50 pounds per acre and potassium to 200 pounds to 300 pounds per acre. Based on the soil test, adjust the soil pHw level to 5.5 to 6.5, if needed, with lime or powdered sulfur (as appropriate) incorporated into the soil at least six months in advance of planting. Supplement soil organic matter to a level of 3-5 percent. Do not apply nitrogen at planting time; a light application (no more than 10 pounds per acre) of nitrogen may be made four weeks to eight weeks after planting. Mature bearing blackberry plantings benefit from 60 pounds to 80 pounds of nitrogen per acre annually, applied as blossoming begins in April. Additional nutrients, such as phosphorus and potassium, are applied as indicated by soil or foliar test results.
Cultivar Selection
| Cultivar | Ripening | Fruit Characteristics | Yields | Bush Type | Notes |
| Apache | late | Large fruit, moderate firmness, good flavor | Med-high | Upright | Thornless, floricane fruiting |
| Arapaho | early | Medium fruit, excellent firmness, good flavor | Med-low | Upright | Thornless, floricane fruiting |
| Chester | late | Large fruit, good firmness, good flavor | High | Semi-erect | Thornless, floricane fruiting |
| Chickasaw | midseason | Large fruit, moderate firmness, good flavor | high | Upright | Thorny, floricane fruiting |
| Choctaw | early | Medium fruit, good firmness, good flavor | Med-high | Upright | Thorny, floricane fruiting |
| Kiowa | Midseason-late | Very large fruit, moderate firmness, good flavor | High | Upright | Thorny, floricane fruiting |
| Natchez | early | Very large fruit, moderate firmness, good flavor | High | Upright | Thornless, floricane fruiting |
| Navaho | late | Medium fruit, excellent firmness, good flavor | Med-high | Upright | Thornless, floricane fruiting |
| Osage | Early-midseason | Large fruit, good firmness, good flavor | High | Upright | Thornless, floricane fruiting |
| Ouachita | early | Large fruit, good firmness, good flavor | High | Upright | Thornless, floricane fruiting |
| Primark 45 | Midseason
(floricane crop) Late (primocane crop) |
Med-large fruit, good firmness, good flavor
reduced primocane yields in hot summers |
Med | Upright | Thorny, primocane fruiting |
| Primark
Freedom |
Early (floricane crop)
Late (primocane crop) |
Large fruit, moderate firmness, excellent flavor
reduced primocane yields in hot summers |
Med | Upright | Thornless, primocane fruiting |
| Triple
Crown |
late | Large fruit, moderate firmness, excellent flavor | High | Semi-erect | Thornless, floricane fruiting |
Planting
Form planting rows into “berms,” or raised ridges, prior to planting, or plant on level ground. Establish a non-competitive ground cover in the alleys between rows to facilitate operations in the planting. Planting rows are typically spaced 10 feet to 12 feet apart, and space plants 3 feet to 6 feet apart in the planting row, depending on the type of blackberry. Plant in spring. Plant virus-tested, tissue cultured plants for best performance.
Cultural Management
Blackberries perform best when trellised. Prune blackberries annually.
Water Management
Blackberries are not drought tolerant and require 1 inch to 2 inches of water per week for optimum growth and fruit development. Drip or trickle irrigation systems are useful for blackberry.
Weed Control
Control problem perennial weeds such as bermuda grass, Johnson grass, wild blackberry and poison ivy before planting blueberry. Mulches and weed barrier fabric are helpful in controlling weeds in established plantings. Herbicides labeled for weed control in blackberry:
- Preemergence control : carfentrazone, dichlobenil, diuron, halosulfuron, isoxaben, napropamide, norflurazon, oryzalin, simizine, sulfentrazone, terbacil, and trifluralin.
- Postemergence control : carfentrazone, clethodim, diquat, fluazifop-p, glyphosate, paraquat, pelargonic acid, and sethoxydim.
Insects and Diseases
Insect and mite pests of economic significance include Japanese beetle, spotted wing drosophila, raspberry crown borer, rednecked cane borer, tarnished plant bug, stink bug, thrips, and mites. Diseases of economic significance include orange rust, anthracnose, spur blight, cane blight, phytophthora root rot, septoria leaf spot, botrytis fruit rot, and powdery mildew.
Harvest and Storage
Floricane blackberry harvest takes place in June, July and August; primocane harvest is in August and September. Fruit is harvested when fully ripe and completely colored. Blackberries are harvested by hand in Missouri. Harvest blackberry plants at 3-4 day intervals. Cool harvested fruit as soon as possible, and store under refrigeration. Fruit stored under proper conditions has a maximum shelf life of seven days. A mature planting may yield 7,000-10,000 pounds of fruit per acre.