How to Prune Thornless Blackberries

by Alex Kountry
Updated on

Find out how to prune your thornless blackberry bush for the best fruit production. Tips on the best time of year to prune, how to cut, and what to look for.

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Pruning thornless blackberries is a necessary part of their care to ensure a bountiful crop of fruit. While the canes (the stems that produce the berries) can grow quite long, they should be cut back each year to encourage new growth. This article will give you tips on when and how to prune your thornless blackberries.

Thornless blackberry plants are biennial, meaning that they produce fruit on 2-year-old canes. The canes that bore fruit the previous year will not produce fruit the following year, so they should be removed. In late winter or early spring, cut these canes off at the ground level. This will also help to encourage new growth.

New canes will grow from the base of the plant, and these are the ones that you want to keep. Once they have reached about 2 feet in height, you can begin to train them by tying them to a support system. Be sure to leave enough space between each cane so that they have room to grow. When pruning, cut off any dead or damaged sections of the cane, as well as any suckers (new growth that is not from the base of the plant).

In late summer or early fall, after the berries have been harvested, you should prune any remaining canes back by about half their length. This will encourage new growth and help to keep your plants healthy.

Following these tips on how and when to prune your thornless blackberries will help ensure a bountiful crop of berries each year!

What You’ll Need

Pruning shears
Thornless blackberry bushes

Pruning Thornless Blackberries

Pruning thornless blackberries can seem daunting, but with a little bit of know-how, it can be easy! You’ll want to start by cutting off any dead or diseased canes, as well as any that are crossing or rubbing against each other. next, you’ll want to thin out the remaining canes so that there are about 6-8 per plant. Finally, cut the canes back to about 24 inches.

Summer pruning

Summer pruning is done to promote the growth of new canes that will produce a crop the following season. It also helps to control the size and vigor of the plant. As a general rule, you should remove about one-third of the canes each year.

Start by pruning out any dead, diseased or damaged canes. Then, remove any canes that are more than 2 years old. These older canes are less productive and more prone to disease. Finally, thin out the remaining canes so that there are only 3 or 4 per mound.

Pruning thornless blackberries is a bit different than pruning other types of berries. Since they don’t have thorns, you don’t have to worry about them scratching you as you prune. However, you do need to be careful not to damage the delicate canes.

The best time to prune thornless blackberries is in late summer or early fall, after the berries have been harvested.

Winter pruning

Thornless blackberries are usually grown as cordons (single-stemmed plants with lateral fruiting spurs) or fan-trained plants. They can also be grown as free-standing bushes. All trained blackberry plants require annual pruning to promote fruiting wood and to keep the plant under control.

Blackberries produce fruit on 1-year-old and older canes, so it is necessary to retain some old canes each year while removed some of the weaker, less productive canes. Winter is the best time to prune thornless blackberries because the plant is dormant and it is easier to see the structure of the plant.

When pruning, always use clean, sharp tools to avoid damaging the plant. Make sure to remove all dead, diseased, or damaged canes. To start, cut out any weak or spindly growth. Next, thin out the remaining canes so that there are 4-6 strong canes per linear foot of cordon or 8-10 per foot of fan-trained row. Finally, cut back all laterals on 1-year-old canes to 6-12 inches (15-30 cm). This will encourage the formation of strong fruit buds for next year’s crop.


Pruning your thornless blackberries is important to encourage new growth, prevent disease, and improve air circulation and sunlight penetration. By following the simple tips in this article, you can keep your thornless blackberries healthy and productive for many years to come.

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About the author

Alex Kountry

Alex Kountry is the founder of HayFarmGuy and has been a backyard farmer for over 10 years. Since then he has decided to write helpful articles that will help you become a better backyard farmer and know what to do. He also loves to play tennis and read books