Pruning Blackberries in the Fall for Beginners: Tips and Tricks

Why prune blackberries in the fall

For garden blackberries, like most representatives of the Rubus genus, a two-year development cycle is typical. So, with a perennial rhizome, the useful life of the aerial part (shoots) is calculated in two years: in the first year, the young shoot grows, is looked after, covered for the winter, and by the second year it becomes stiff, blooms in spring, and then brings the harvest. This is where its function ends, and immediately after harvest (in September) it must be removed. If the old stems are not removed, they interfere with the growth of new shoots and thicken the bush.

It should be clarified that not only the old, obsolete shoots are subject to pruning, but also part of the young annual shoots. Weak, too thin or diseased stems of the first year must be removed at the base, and healthy and promising ones should be shortened by 20–40 cm. Such pruning contributes to abundant flowering next spring. 

When cutting a bush for the winter, do not feel sorry for it – feel free to cut out all that is superfluous. Blackberries have incredible growth vigor, and the more shoots removed, the more new ones will grow.

The tops of young stems can be shortened by a third, since the fruiting zone of the blackberry is located in the center of the shoot.

In general, autumn pruning has several goals:

• efficient use of nutrients – old and used shoots also need food;
• shadow elimination – old shoots create an additional shadow, which slows down the ripening of berries;
• increasing winter hardiness and preservation for the winter – thickened shoots with old stiff shoots are much more difficult to cover than young flexible shoots;
• increased productivity – pruning young shoots in the fall contributes to abundant flowering and fruiting;
• bush strengthening – if blackberry thickets are thinned out, young stems become more powerful and strong.

Cutting technology

Autumn pruning is carried out after the end of the harvest. For most varieties, this period falls on the beginning of September. However, there is a garden blackberry with two fruiting waves – for such varieties, the pruning procedure is carried out a little later (in October).

To trim correctly, you need to follow the following sequence:

1. At the first stage, all shoots that bear fruit this year are removed – they should be cut at the root, leaving no stumps, as they can rot, and spread this process to healthy branches.
2. Among young shoots, underdeveloped ones (short, thin) are also removed under the root – they will not bring a crop, so there is no need to leave them.
3. Further, all diseased and damaged shoots are subject to complete removal (at the root) – they will not survive the winter and, moreover, can infect healthy branches.
4. Now, based on the state of the root system, we calculate the possible load on the bush. On average, a healthy plant is able to fully provide nutrients to 6-8 fruiting shoots, so we leave the 10 strongest, in case a few branches do not survive the winter, and cut the rest under the root.
5. We shorten the remaining shoots by about 20-30 cm, if the branches are very long, you can cut more. It is correct to do pruning immediately above the kidney.

In this state, the bush is covered for the winter. They take shelter in the spring, in March or April, it all depends on the temperature. Plants freed from shelter should be inspected for the integrity and viability of the shoots. Healthy branches are elastic in appearance, with a shiny brownish bark, frozen branches are loose and brittle, they should be removed. Wintering is considered successful if 5-6 branches are preserved, it is also not bad if 4 are left – the yield will be at a good level. Three or fewer healthy lashes will not bring a large harvest, but the berries will be larger.  

Shrub formation

Because garden brambles come in many varieties and shapes, pruning is not always quick or successful. It all depends on what kind of blackberry you grow: creeping or erect. For example, upright bushes are more difficult to cover, as the shoots do not bend well and are very brittle, while creeping blackberries can form real thickets of long lashes, which are sometimes difficult to even separate.

In order to somehow simplify the pruning process, the formation of a bush is used – the direction of the shoots in the right direction.

As a rule, the formation is carried out in the spring, but if by autumn the bush has grown strongly and pruning has become difficult, then you can arrange the plants before pruning.

For blackberries with upright shoots, it is correct and convenient to use the fan shaping method, which is as follows:

1. All shoots must be raised vertically onto the trellis, directly above the root.
2. Next, we divide the bush into two parts and direct the whips on both sides, like a fan, tying them to the bottom of the trellis.
3. Now that all the shoots are visible in the root part, we first cut out all the old shoots that bear fruit this year under the root.
4. Then we remove weak, too thin and diseased young branches.
5. We leave 8–10 of the strongest young shoots and shorten them by a quarter (20–40 cm).
6. We remove the whips from the support, press them to the ground and cover with insulation.

The formation of creeping blackberry bushes occurs in a slightly different way. Its many-meter weaving shoots bend beautifully, but it is very difficult to cut and shape them, so the following method is used:

1. Shoots are divided into old (fruitful this year) and young, which will yield next year.
2. Then, they are wound on a trellis, like a thread on a spool – the old ones in one direction, for example, to the right, and the young ones to the left.
3. We cut out the old growth at the root.
4. Of the young shoots, we leave 8–10 of the strongest, and cut out the rest.
5. Next, we remove the blackberry from the trellis, fold it again, put it in a prepared trench for wintering, and cover it.

Remontant varieties of berries deserve special attention. Their pruning and shelter is the simplest event in the entire agricultural technology of culture. You just need to cut out all the shoots formed over the summer to the root and cover with any insulating material – in the spring new lashes will grow that will bloom and delight with a bountiful harvest.

Video “How to cut a blackberry”

This video will tell you how to prune a blackberry bush and why it is important to do it in the fall.