Depending on which part of the country you live, blackberries are seen as either a delicacy or an aggressive weed. If not cared for properly, the plants can get away from you and take over sections of your yard. However, with a little attention and minimal work, they will make an amazing addition to any yard. Loganberries, boysenberry, marionberry and many other varieties are included in the blackberry family, and can range in color from jet black to a reddish purple. Some are thornless and others have aggressive, scratchy thorns. Three classifications of blackberries exist and need different pruning and training methods: trailing,
erect, and semi erect (cross between trailing and erect). All blackberries are self-fruitful and bear their fruit in the summer on two-year old canes. There are a few everbearing varieties that produce fruit in the fall as well as a summer crop, and have slightly different pruning requirements.
Location
Plant in an open site in full sun, or a little late afternoon shade. In very cold areas, plant on a south facing slope to assist with hardiness. Pick a location with good soil drainage.
Soil
Blackberries prefer deep, well-drained soil with a high organic matter content - the less clay the better. Sandy soils work fine, but avoid heavy clay soils if possible. Use heavy mulches to prevent weeds, keep soil consistently moist, and to assist in winter hardiness. Plants are susceptible to iron chlorosis if planted in alkaline soils. Acidifying soil each year with sulfur will assist with fruit production.
Planting
Plant in early spring, after the last hard frost in cold climates. Make sure to position crowns (right where the roots start spreading from the cane) about 1" below the surface when backfilling. space erect plants 2-3 feet apart and trailing and semi erect plants 5-6 feet apart. All rows should be 10 feet apart. See bare root and container planting guide.
Water
Make sure to provide regular water throughout the growing season - usually a deep watering every 5-10 days depending on heat and sun exposure. Drip or soaker systems are preferable, but overhead sprinklers will work fine as well.
Fertilizer
Use a balanced fertilizer with micronutrients in early spring before the new growth begins to emerge to maintain consistent growth and fruit production. We recommend Anderson’s Best: That’s All It Takes, Fertilome Fruit, Nut and Pecan food, or Natural Guard Organic Fruit and Citrus Fertilizer. Plan on 1 pound (about 2 cups) for a 30 foot row. A second, light application just after fruit set will help keep the plants growing and boost productivity. If iron chlorosis occurs, use a chelated iron supplement like EDDHA 6% Iron. Blackberries prefer a more acidic soil, so yearly or even bi-annual applications of sulfur can help maintain a
lower pH.
Pruning
Blackberry roots are perennial, meaning, once established, they will come back year after year. The canes, however, are mostly biennial - they grow the first year, and produce flowers and fruit the second, then they should be removed. When pruning blackberries, it is important to know the difference between one and two-year-old growth.
Trailing and semi erect types should be allowed to grow unrestricted the first year. The second year, train the year old canes onto a trellis or fence support of some sort. After harvesting, cut all the canes thathave fruited to the ground. Then either in the fall or early spring, train the new year-old growth to the trellis
where the old canes were removed. Prune the year-old canes back to 5-8 feet which will encourage more fruit producing side branches. Triple Crown is a good example of a trailing variety of thornless blackberry. Erect blackberries don’t need extra support from a trellis or fence, but are commonly attached to them to
help keep the canes organized. In mid-summer of the first year, trim the canes back to 2-3 feet to encourage side branches. In late fall or early spring, trim the side branches back to about 12-15 inches. After the canes produce fruit the second year, trim them to the ground to allow new growth to replace the canes that already produced fruit. Arapaho and Baby Cakes are two examples of thornless, erect varieties.
Harvest & Yield
Pick fruit when berries are fully developed, have deep, mature color, and are sweet to the taste. If berries are still shiny, they are not fully ripened yet. Wait until they start to have a dull appearance before picking. Gently grasp the fruit and twist or snap it from the vine rather than a pulling motion which can damage the fruit. Fruit can get crushed easily if piled too deep on top of each other, so harvest with a broad, shallow container to prevent damage. Anticipate 3-5 pounds of fruit per plant for erect varieties; 10-15 pounds of fruit per plant for trailing or semi erect plants.
Pests
Multiple diseases attack blackberries and can severely damage your crop: botrytis, anthracnose, mildews, leaf spot, root rot and others. As needed, apply a general-purpose fungicide like Copper Soap from Natural Guard or Complete Disease Control from Monterey (both products are organic and very safe to use on edibles right up until harvest) to prevent and control disease outbreaks. The
Complete Disease Control can also be applied as a soil drench in early spring and again once a month during the growing season to prevent many of the most damaging diseases (like verticillium) before they get established.
Aphids, mites, cane borer, slugs and snails are the most common insect pests that attack blackberries. Avoid over watering, watch for telltale signs on the leaves of insect damage, and apply insecticides only as needed to control the
most difficult of pests. Sevin, permethrin, and Spinosad Soap have the broadest range of control, but are the safest to use closer to harvest season. Read each label specifically for harvest intervals after application.
Varieties
Arapaho
Arapaho is a thornless blackberry variety that is disease resistant and very hardy. They heavily produce good sized, sweet berries. They generally begin bearing in two years. Begins to ripen early towards the beginning of June. This is a self-supporting plant so no trellises are needed. Rhizomes spread readily so the blackberries will spread; digging these new plants may be necessary to keep them from spreading into unwanted areas.
- Zones: 5-9
- Height: 4'-5' tall
Triple Crown
Triple Crown is a fast growing thornless blackberry. It grows about 4’-5’ tall and, like other blackberries, will spread readily. The shrubs are semi-erect and will require some trellising for best production, but will still produce heavily without. Plants ripen from roughly July 10 to about August 10 in most areas. This variety yields large, glossy black fruits that are very sweet and firm and have the capacity to produce larger berries than any other variety. Begins to bear on two-
year-old plants. Mature plants can produce for up to 6 weeks.
- Zones: 5-11
Bristol
This black raspberry is a heavy producer with sweet, firm fruit that won’t bleed when handled. It often out produces its competition 2 to 1. This berry wins more
and more friends every year. Bristol’s upright growth and cluster formation make its berries extremely easy to pick. Berries have excellent quality and good flavor
and are good for canning and freezing as well as fresh eating. This is a very hardy, vigorous plant that ripens in mid-July. Shows a tolerance to powdery mildew.
- Zones: 4-8
- Height: 3'-4' tall
Loganberry
Black raspberries have a distinct and moderately tart flavor, small seed and like the red raspberry, contain a hollow core. It is also widely known as “Black Caps.”
The Loganberry is a distinct tart flavor and tiny seeds. It produces on first-year wood so once canes produce they can be pruned back to the ground. Additional
pruning will be required to eliminate tangling and improve their ability to bear. Loganberry is a very hardy and dependable producer. Widely adaptable.
- Zones: 4-8
- Height: 3'-4' tall
Boysenberry
Boysenberries bear fruit on 2–year old wood. These brambles thrive in most soil types but they do not tolerate poor drainage. Purple-black berries have an intense flavor, are nearly seedless and very juicy. A cross between the raspberry and the blackberry, it is a more flavorful berry than either of its parents. These plants will need several inches (6 or more) of mulch, straw, or other winter protection in colder climates.
- Zones: 5b-8
- Height: 4-6 feet - trailing vines
- Spacing: 5'
- Spread: 6-8'
- Sun/Shade: Full sun
- Pollinator: Self-pollinating
- Blooms: May
- Fruit: Very large reddish purple to black berries