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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

<a title="View user profile." href="/author/editors">The Editors</a> Fri, 07/31/2015 - 14:46

For starters, you might cut down to the ground any canes that have already fruited (floricanes)--those with dead leaves, or old fruit on them. This is usually done in late summer, after the floricanes have stopped fruiting. At any time, you can remove any other canes that are damaged or diseased, or remove any canes that extend at ground level beyond the area where you want the plant to grow. If possible, you can set up a trellis and tie the canes that you would like to keep to it, to keep them from blocking the doorway. You can also trim back the primocanes (the 1-year-old canes that will fruit the second year) to about 3 or 4 feet. Some gardeners select just 4 to 8 primocanes to keep for next year's harvest, and prune out the other primocanes.

 

In spring, gardeners often prune off the tips of the canes back to about 24 inches, which encourages branching and more fruit.

 <span>Elizabeth2222</span> Sat, 07/11/2015 - 14:09
Hi I have blackberries with what they look like is white or tan druplets and by reading some of the comments I think this is from the sun and wind which we had both. I am located in new jersey atlantic county. Should I use the pyganic? I also have blackberries that seem to have a light purple druplet and after picking them overnight seem to rot and taste sour. I don't know why. I am about 3 weeks into picking them. The first 2 and half weeks they were fine and now this. we also have had a lot of rain. Is there anything I can do? thandk you
<a title="View user profile." href="/author/editors">The Editors</a> Tue, 07/14/2015 - 07:12

You are correct about the white or tan drupelets. This discoloration usually happens when the temperatures suddently change (example 70 to 90) and are accompanied with a drop in humidity (think dry air) and are exasperated by wind. All of these factors allow more UV rays to hit the fruits. However, they are still edible (just not marketable).

To avoid this issue, you can use mist the fruits or cool them down with overhead irrigation. Just avoid wetting them down in the evening so that the fruits have a chance to dry.

Blackberries will taste sour if they are picked too early. They turn black before they are ripe but you need to wait until they are dull and soft before picking.

Another reason for sour fruit is due to lack of watering. Your UV/discoloring issue suggests that this may be the case. It's important to provide deep and consistent watering to your blackburry bushes-- about 1 to 2 inches of water a week between May and October, and more if it's hot and dry.

 <span>Kayla Foust</span> Tue, 07/07/2015 - 12:04
I came across multiple blackberry bushes on our farm yesterday while walking with our children. Are these okay to pick and eat? Do I need to look out for certain things?
<a title="View user profile." href="/author/editors">The Editors</a> Wed, 07/08/2015 - 15:18

Hi, Kayla, Lots of berries are black, so we can't be sure which you've found. Here's a page with illustrations and details on a variety of berries (black and otherwise). See if yours is in here: http://www.extension.umn.edu/garden/yard-garden/fruit/wild-and-edible-fruits-of-minnesota/ —even if you are not in Minnesota, it may be useful information.

 <span>Nettles96</span> Sat, 06/27/2015 - 19:07
I planted my blackberry plant last spring of 2014. It grew well, was trellised and is about 5' in length. It is June 27, 2015 and there are no leaves yet. I scraped in a few spots and it looked ok still had a greenish color. What could cause the leave not to bloom and form the flowers need to produce fruit.
<span>Omar Nuri</span> Sat, 06/20/2015 - 19:52
About two years ago I bout five mix plants of blueberries and raspberry, One of them grew about 5-10 long 20 feet branches with much fruits on the first year. From what I read here it appear to be thornless, smooth stem blackberry. The fruit is longer, larger and sweeter than the wild blackberry which grows everywhere here in the Pacific northwest ( Seattle area). This year in addition of much growth, there are tons of berries that will be ripe soon. Questions: 1. Is it what I think it is? 2. How to prune them 3. How to protect it from birds and bees 4. Can I grow Mulberry here in the Pacific Northwest Thanks, you got a very informative site.
<a title="View user profile." href="/author/editors">The Editors</a> Tue, 06/23/2015 - 10:44

Thornless blackberries are popular in the Washington state area--and known for their large, sweet, abundant berries. You need to regularly prune. When the new canes reach 4 feet tall in summer, tie them back. They'll form some (side) branches which will stick out. In the spring, cut those lateral branches back to 2 feet long. In fall, cut all the canes that produced fruit to the ground. Every year the new canes will produce more fruit in the summer. For the birds, try bird netting a few weeks before the berries ripen. Yes, there are Mulberry Trees suitable to where you live.

 <span>Nina Turney</span> Sat, 06/20/2015 - 11:10
I have thornless blackberries that are always covered with red berries but as they ripen to black, many of the buds(seed) in each berry are white. What is problem, what is solution?
<span>Chris Groudas</span> Tue, 06/23/2015 - 08:47
This is usually caused by hot weather or thrips during blooming. Try using a mild pesticide like Pyganic 1-2 per week during bloom and this should eliminate most of the the while spots (in berries.