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How to Grow Blackberries: The Complete Guide

Image Credit:
Pixabay
Botanical Name
Rubus fruticosus
Grown as
Perennial
USDA Zones
5a
5b
6a
6b
7a
7b
8a
8b
9a
9b
Toxicity
Non-toxic
Sun Exposure
Full Sun
Water Needs
Moderate
Height
6-10 feet
Spread
3-6 feet
Soil pH
Acidic
Bloom Time
Summer
Flower Color
White
Special Features
Erosion Control
Attracts Butterflies
Attracts Pollinators
Attracts Songbirds
Resilience
Clay Soil Tolerant
Heat-Tolerant
Plant Type
Fruit
Written By: Catherine Boeckmann Executive Digital Editor and Master Gardener

Blackberries, like raspberries, are very easy to grow. Once this native berry is ripe, get ready for an abundant harvest, picking every couple of days! Here’s how to grow and harvest blackberries in your backyard.

All blackberries are perennials; the roots survive year after year. However, the top of the plant above the soil is what we call biennial. This means that the canes grow vegetatively for a year, bear fruit the next year, and then die. However, every year the plant sends up new canes to replace those that died! For a great fruit harvest and to avoid a messy plant, pruning is important. (Learn about proper pruning techniques below.)

Planting

When to Plant Blackberries

  • Plant when the canes are dormant, preferably in early spring.
    • Planting may also be done in late fall; however, it should be delayed until early spring in very cold areas, as low temperatures could kill some hybrid varieties.
  • Blackberries and their hybrids are all self-fertile, so multiple plants are not needed for fruit production.

Choosing and Preparing a Planting Site

  • Select a site that receives full sun for the best berry yields.
  • Soil needs to be fertile with good drainage. Add organic content to enrich your soil. (Learn more about soil amendments and preparing soil for planting.)
  • Make sure you plant your blackberries far away from wild blackberries, which may carry (plant) diseases that could weaken your own plants.

How to Plant Blackberries

  • For semi-erect cultivars, space plants 5 to 6 feet apart. Space erect cultivars 3 feet apart. Space trailing varieties 5 to 8 feet apart. Space rows about 8 feet apart.
  • Plant shallowly: about 1 inch deeper than they were grown in the nursery.

Growing

How to Care for Blackberries

  • Mulching is important throughout the season to conserve moisture and suffocate weeds. Keep a thick layer of mulch surrounding plants at all times.
  • Blackberries require plenty of moisture, especially when growing and ripening. Ensure plants receive 1 inch of water per week and more in hot temperatures.
  • Blackberries benefit from fertilizing in early spring with an all-purpose fertilizer such as 10-10-10, or a 16-16-8. 

Trellis Trailing Blackberries

As mentioned above, trailing blackberries need a trellis or support. Explore a two-wire system, running a top wire at 5 to 6 feet with a second line 18 inches below the top wire. After the first year, there will be fruiting floricanes along the wires. Train the new primocanes into a narrow row below the fruiting canes. Directing all canes in one direction may make it simpler.

Pruning

We have provided detailed pruning information below, but do not be scared. The main idea is to simply remove the old canes that already bore fruit and let new ones take their place. 

  • Trailing blackberries: After the fruit harvest period, the old fruiting (floricanes) are removed to the ground. However, unless there is a lot of disease, it’s best to delay removing the old fruiting canes until they have died back considerably. This allows the dying canes to move nutrients back into the crown and roots. After you remove the old fruiting canes, you may train the primocanes up on the wires. Work with one or two canes at a time in a spiral around the trellis wires. Canes from adjacent plants may overlap a little. No pruning of primocanes is necessary.

In areas with low winter temperatures, it’s fine to leave the primocanes on the ground for the winter, where they could be mulched for winter protection. In the spring, after the danger of extreme cold has passed, train the old primocanes (now considered floricanes) up on the wires. Avoid working with the canes in cold weather, as they are more prone to breaking.

  • Erect blackberries produce stiff, shorter canes that come from the crown and from root suckering (often forming a hedgerow).

    Erect blackberries benefit from summer pruning. Remove the top 1 to 2 inches of new primocanes when they are 4 feet tall. This causes the canes to branch, increasing next year’s yields. Plants will require several pruning sessions to tip each cane as it reaches the 4-foot height. Primocanes (suckers) that grow outside the hedgerow should be regularly removed.

    In the winter, remove the dead floricanes (old fruiting canes) from the hedgerow. Also, shorten the lateral branches to about 1½ to 2½ feet.

  • If you have primocane-fruiting erect blackberries, which are harvested in late summer/early autumn, cut all canes to the ground in the late winter (after the fall crop). In the summer, when the primocanes are 3½ feet tall, remove the top 6 inches. The primocanes will branch, thereby producing larger yields in the fall.

  • If you have semi-erect blackberries, they are easier to manage on a Double T Trellis. Install 4-foot cross arms at the top of a 6-foot post. Install a 3-foot cross arm about 2 feet below the top line. String high-tensile wire down the rows, connecting to the cross arms.

    Semi-erect berries need to be pruned in the summer. When the primocanes are 5 feet tall, remove the top 2 inches to encourage branching. Several pruning sessions will be required as canes reach the appropriate height. In the winter, remove the dead floricanes (old fruiting canes). Spread the primocanes (new floricanes) out along the trellis. Canes do not need to be shortened. However, they can be if they are difficult to train.

Harvesting

How to Harvest Blackberries

  • Pick only berries that are fully black. Mature berries are plump yet firm, a deep black color, and pull freely from the plant without a yank. Berries do not ripen after being picked.
  • Once blackberries start to ripen, they must be picked often—every couple of days. 
  • When picking, keep the central plug within the fruit (unlike raspberries).
  • Harvest during the cooler parts of the day. Once picked, place berries in the shade and refrigerate as soon as possible.

How to Store Blackberries

  • Blackberries are highly perishable and will only last a few days once harvested, even with refrigeration. 
  • Although fresh fruit is always best, blackberries can be stored by canning, preserving, or freezing. Techniques used for freezing blueberries can also be used on blackberries.

Pests and Problems

  • Raspberry Borers
  • Fruit Worms
  • Gray Mold
  • Viruses
    • If your plant is suffering from the blackberry disease known as Raspberry Bushy Dwarf virus, the leaves will have some bright yellow on them, and the leaves of the fruiting vines may have a bleached look in the summer. The disease known as Blackberry Calico will cause faint yellow blotches on the leaves of the plant.

Types

Basically, there are three types of blackberries:

  1. Erect thorny blackberries
  2. Erect thornless blackberries
  3. Trailing thornless blackberries

Erect blackberries are bushes that support themselves, while the trailing blackberries have long canes that must be trellised for support.

Wit and Wisdom

Blackberries, raspberries, and strawberries are very high in ellagic acid, which is an antioxidant that acts as a scavenger, helping to make potential cancer-causing chemicals inactive. Ellagic acid reduces the genetic damage caused by carcinogens like tobacco smoke and air pollution. Blackberries also contain other antioxidants that can help lower cholesterol and ward off cardiovascular disease.

Fruit

About The Author

Catherine Boeckmann

Catherine Boeckmann

Executive Digital Editor and Master Gardener

Catherine Boeckmann loves nature, stargazing, and gardening, so it’s not surprising that she and The Old Farmer’s Almanac found each other. She leads digital content for the Almanac website and is also a certified master gardener in the state of Indiana.

Read more from Catherine Boeckmann

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Comments

<span>Charles Mcachran</span> Thu, 08/29/2013 - 22:07
When I tried mulching my blackberries to cut down on the grass and weeds I got bugs and insects in the mulch. The birds came and got the bugs and insects along with my blackberries so I gave up on the mulch and do the best I can to eliminate the grass and weeds. I do not like to use chemicals in my blackberry patch.
<span>R Hays</span> Sun, 11/16/2014 - 10:43
Charles, I have over 8 miles of trellised blackberries I use literally tons of mulch. All of mine is in the form of pine straw and hardwood leaves. I am a chemical free farmer. Not any pesticides or herbicides. I use sticky tapes and traps from planet natural and vinegar traps for the fruit flies. I prefer the mulched leaves over the whole ones, but I will take whatever I can get from the nearest city that calls me to come get all of the bags of leaves.
<span>Hummingbirdbear</span> Fri, 07/26/2013 - 11:32
should I put up trellises? and I have 15 acres and I would say there is probably 3 or 4 acres of them spread from one end to the other. I've been working on it in 1 spot for four hours and have barely made a dent in it. I hope it is worth it.
<span>Charles Mcachran</span> Thu, 08/29/2013 - 22:16
Putting your plants on trellises gets them off the ground and I understand that if you trim the canes back a bit, they will branch out laterally and should give you more berries per bush. If you have a lot of bushes, this will take time and money to get them all off the ground but it should pay off eventually and they are easier to deal with and get the fruit.
<span>R Hays</span> Sun, 11/16/2014 - 10:51
I have found that not pruning my berry vines produces more fruits. Most growers get about 2.5 gallons of berries per plant I am getting on average 4.25 gallons per plant. In all of the biology classes I have taken in high school and college taught me that the leaves are the energy making factories of the plant. The more energy that goes into the plants roots the more energy to produce ripe berries. Some of my plants are 27 feet long with laterals up to 14 feet in length. On those plants I will get as many as 12 gallons of berries per plant.
<span>Hummingbirdbear</span> Fri, 07/26/2013 - 11:34
hank you for your time! it is greatly appreciated.
<span>Luv Berries</span> Fri, 07/26/2013 - 09:06
I noticed on my thornless blackberry bush that it has fruit worms, How can I get rid of them?? and are these worms harmful?/
<a title="View user profile." href="/author/editors">The Editors</a> Fri, 07/26/2013 - 10:24

The worms are probably a larval form of a fly or beetle. Pick them off by hand or soak the berries in salted water for about an hour. The worms will float to the top of the water and then can be removed.

 <span>Alan Haber</span> Fri, 07/26/2013 - 05:27
we have a giant (thorny) blackberry clump, about 20 feet in diameter, 6 or 8 feet high. unpruned for many years, now full of stems with fruit developing and many long stems with no fruit. i pruned back the fruitless stems to give the fruited ones better light and easier access. i can't get to the top at all.
<span>Helen Kempton</span> Wed, 07/24/2013 - 09:58
Our wild black raspberries have some brown spots on them. Many of the branches that bear fruit have dried up instead of producing berries.The patch has been there untended a long time-we move here recently. Are the berries safe to eat if they have a brown spot on them? Should we only eat berries without blemishes? Thanks!!!!!