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Should you prune blueberry bushes


Pruning Blueberry Bushes in the Home Garden

Gary Gao, Ph.D., Associate Professor and Small-Fruit Extension Specialist, OSU South Centers, and Adjunct Associate Professor, Department of Horticulture and Crop Science, The Ohio State University

Maurus Brown, Ph.D., Associate Professor Emeritus, OSU South Centers

Growing blueberries in the home garden can be quite enjoyable. Blueberries have a very fresh taste when picked straight off the bush. Beyond the initial challenge of establishing a new planting, there are really few pests that attack blueberry bushes. Proper weeding, fertilizing, insect and disease control, and proper pruning help to assure quality fruit at harvest. This fact sheet is intended to help home fruit growers gain a better understanding of the principles of pruning blueberry bushes. Refer to the glossary of terms if you are not familiar with some of the terms used in this fact sheet.

Why is it important to prune blueberry bushes?
 
  Figure 1. Blueberry bushes that have not been pruned regularly tend to produce fewer new shoots and small berries that are of inferior quality. Photo by Gary Gao, OSU South Centers.

The biggest and tastiest blueberries are typically borne on strong and newer canes in the upper half of the bush and in more upright position. Any pruning of blueberry bushes, especially mature bushes, is required for successful production of blueberries. Blueberry bushes that have not been pruned on an annual basis may become overgrown and less fruitful (Figure 1). Proper training of blueberries is essential to maintain plant size, shape and productivity. In the first two years, it is important to train young blueberry bushes to promote the proper structure of the plant for maximum fruit production.

What are the steps to successfully prune a blueberry bush?

The best blueberries are produced on 2- to 4-year-old canes. Older canes tend to be weaker and produce smaller berries. Hence, blueberry pruning is a constant renewal process where older canes are removed to encourage new, strong and more upright growth. Refer to Figures 2 and 3 for the types of the canes that need to be removed.

Here are the steps in properly prune blueberry bushes:

  1. Visually observe the blueberry bush.
  2. Imagine what the plant should look like when pruning is completed.
  3. Look for the strongest canes with the best flower buds and save them.
  4. Remove all diseased and broken canes.
  5. Remove dead twigs.
  6. Remove canes that are seven years old or older.
  7. Remove weak and twiggy canes canes with a lot of flower buds.
  8. Retain strong canes with many large flower buds.
  9. Remove short and low hanging canes.
  10. Prune very hard once every a few year to rejuvenate the bushes.

One-year-old canes are reddish brown during the winter months and the fruit producing canes. Keep in mind that selective pruning will help to stimulate new cane growth each year. Once you are done pruning, the bush should be: (a) narrow at base, (b) open in the center, and (c) free of vegetative clutter.

Figure 2. A mature blueberry bush before pruning. Figure 3. A mature blueberry bush after pruning.
 
Are individual blueberry varieties pruned differently?

Yes, different blueberry cultivars should be pruned quite differently. Most gardeners in Ohio grow high-bush blueberries. There are some differences in term of growth habits. For example, ‘Duke’ tends to produce upright canes with few new shoots from the crown. ‘Blue Ray’ tends to grow long and arching canes. ‘Nelson’ produces a lot of new shoots from the crown every year.

Cultivars with upright growth can benefit from cane thinning at the top. More arching cultivars can benefit from shortening of long canes to make the bushes more compact. Bushier cultivars can benefit from cane thinning at the crown.

Can young blueberries be pruned the same as older, mature bushes?

Young bushes generally do not require as much pruning to remove undesirable vegetation. One or two cuts to remove low hanging and weaker canes may suffice. The key to pruning young plants is to focus on setting up the overall plant structure that will make the bush fruitful for several years.

Mature bushes normally require more selective cuts to maintain a desired shape, plant structure and productive fruiting wood. Bushes that are seven years old and older will need to have a few mature canes removed to maintain a balance between older canes that are becoming less productive and young canes that are not quite into full production. Mature bushes should have a mixture of canes of different ages.

How should older, overgrown blueberry bushes be pruned?

Blueberry bushes should be rejuvenated to improve fruit production and maintain proper shape. This may require that several old canes be removed and the bushes be pruned to fit the desired shape. Rejuvenating bushes can be quite a challenge if there has been no annual pruning done for several years. The first approach would be to remove any diseased or broken branches. Secondly, depending on the overall number, the oldest two or three canes should be removed to open up the plant structure. As with any blueberry bush, the center of the plant should be open to sunlight and air movement. The base of the bush (at the top of the root crown) should be tighter than the middle to upper portion of the bush. All branches that are touching and crossing should be removed.

What are the tools used for pruning?

Hand tools, such as loppers, hand pruners and handsaws, can be used to effectively remove all undesired wood from blueberry bushes. Select the appropriate tool to remove wood as cleanly as possible to avoid unnecessary injury to the plant. Hand pruners can be used to effectively remove one-year-old wood. If the wood is two or three years old, it is suggested that a lopper or saw be used to cut through the heavier wood.

Summary

Learning to master the art and science of pruning blueberries takes time and practice. Contact your county Extension educator for updated information on pruning. Make sure your blueberry bushes are pruned each year to maintain the size and shape of the bushes to maximize fruit production and increase the overall fruit quality. The final test of your pruning work is good sized, tasty berries of abundant amounts year after year.

 

Glossary of Pruning Terms
Useful References

Step-by-step Instructions for More Fruit

For backyard blueberry growers, winter means it’s time to break out the pruning shears and folding saw. Pruning blueberries is a task best performed yearly, when the plants are dormant. Closely tied to crop production, plant health, and fruit quality, pruning too aggressively – or not aggressively enough – impacts your blueberry’s performance.

Well-pruned blueberry bushes are healthy and productive.

Reasons for pruning blueberries

Pruning blueberries is an essential winter chore for several reasons.

The goal of good blueberry pruning is to remove enough old growth to encourage the production of new. And to do so without negatively impacting the berry production for the coming season.

Properly pruned blueberry bushes produce better quality fruit. The top berry is from an overgrown plant while the bottom four are from shrub that’s pruned annually.

When to prune blueberries

As with most other fruit-producing trees and shrubs, blueberry pruning takes place in mid to late winter. It’s easy to see the structure of the plant more clearly then and discern which branches are to be removed. In winter, the old branches look very different from the new in color and texture (see photos below). Plus, dormant-season pruning causes the plant less stress. The bush is not in an active state of growth, and no carbohydrate-producing foliage is being removed.

It’s easy to discern an old blueberry branch from a new one. The newer branches are pliable and dark in color, while the old branches are rough-barked and lighter in color.

The regions where blueberries grow well are those with a dormant season of December through early March. Blueberry shrubs are extremely hardy. Some varieties survive down to -35 degrees F. In fact, blueberries need a set number of hours below 45 degrees F (called chill hours) in order for their flower buds to open and produce berries. Without ample cold weather, blueberries do not produce fruit.

Each blueberry type and variety has a slightly different number of required chill hours. Low-chill blueberry varieties require 200-800 chill hours and are best for southern regions. High-chill selections need 800-1000 hours and are ideal for the north. When buying blueberry plants, select a variety that’s suitable to your region.

Late winter is the best time to prune blueberries. Remember, these are very hardy shrubs that do best in cold climates. This plant is badly in need of pruning.

Pruning blueberries can take place as early as late December. However, I recommend waiting until late February or very early March for this task. You’ll be able to prune off any stems that suffered winter injury or breakage due to heavy snows. Plus, the chance of winter injury has largely passed.

The different types of blueberries and their pruning needs

There are many different types of blueberries, including high-bush, low-bush, rabbit-eye, and lots of assorted hybrids. In the north, ‘half-high’ varieties are among the most popular. They are the result of the hybridization of high-bush and low-bush types, and are a great fit for most backyards. They grow 3 to 4 feet in both height and girth, and bear plenty of fruits. Southern gardeners should opt for ‘Rabbit eye’ blueberries as they are more heat tolerant and need fewer chill hours.

Don’t forget that you’ll need at least two different varieties of blueberries to get fruit. Most varieties require a cross-pollination partner. (Those listed in the article linked here, however, are self fertile.) Blueberries are primarily pollinated by our native bumblebees because the vibrations these large bees generate are required for loosening and transferring the pollen in the bell-shaped flowers of blueberries.

Regardless of which type of blueberries you grow, the task of pruning blueberries is the same.

Soon enough, these blueberry flowers will be open and ready to be cross-pollinated with another variety. Bumble bees are the pollinators for this job.

Tips for pruning blueberries

How to prune blueberries depends on whether the plant is new and relatively young or old and overgrown. Below you’ll find step-by-step blueberry pruning instructions for both situations. However, I’d like to share a few key points about pruning blueberries first.

  1. Never shear back blueberries and turn them into the shape of a meatball. Their fruiting buds are located in the outermost 2-3 inches of stem growth. Shearing back the plants removes all the flower buds.
  2. If you don’t properly prune your blueberry bushes, the existing branches will age, but new, fruit-producing branches will not be formed. Older, unpruned blueberry bushes tend to produce more leaves than berries, and any berries that are produced are small and produced only on the outermost stems.
  3. Be sure to use clean, sharp pruning equipment. To avoid the spread of disease, disinfect all pruning equipment before moving from one bush to another. I use a special spray pruning disinfectant that doesn’t gum up or rust your equipment, but you can also dip your tools in a 10% bleach solution or use Lysol spray.
  4. Blueberries produce their flowers on old wood, meaning that the buds for each year’s berry crop are formed during the summer and autumn of the previous season. Protect your blueberry bushes from deer in the winter or they may strip all the buds off the stems.
Blueberry fruiting buds are on the outermost 2-3 inches of the stems. Don’t ever shear blueberry plants or you’ll be cutting off the flowers.

Pruning blueberries step-by-step

Step 1:

Stand back and evaluate your blueberry bushes one at a time. Begin by cutting off any dead or damaged branches. Cut these stems off all the way back to where they join a thicker branch. Do not leave a stump behind as it serves as an entryway for disease. If the entire branch is dead, cut if off back to the ground.

First, prune off any dead or damaged branches. Be sure to use a clean, sharp pair of pruners.

Step 2:

After any damaged stems are removed, cut out any crossed branches, particularly those that rub against each other. After pruning is complete, you want an open structure with no crossed branches. Cut crossed branches off all the way down to the base of the plant.

Be sure to remove any crossed branches as well, or those that rub against each other, cutting them all the way back to the ground.

Step 3:

For young blueberry bushes or those that have been properly pruned in the past: Cut one-third of the remaining branches all the way down to the ground, choosing the oldest and thickest ones for removal. This encourages new, productive canes to emerge from the roots. Yes, that means cut 1 out of every 3 branches clear to the ground to stimulate new stems to emerge from the roots. Do this every winter and you’ll always have excellent blueberry production.

Remove one-third of the stems from each blueberry plant every year, choosing the oldest branches for removal. This encourages new, productive growth to emerge from the base.

For mature blueberry plants that are unpruned and overgrown: Perform a careful renewal pruning to encourage new stem production by cutting half of branches back all the way down to the ground. Always cut off the oldest, thickest ones. This forces new canes to grow from the roots. When a branch is seven or eight years old, production is greatly reduced. If you don’t remove old branches, the plant fails to generate new, more productive stems.

Over the following two to three years, remove the remainder of the oldest branches a few at a time until only newly produced ones remain. The plant continues to produce a moderate crop while the bush is being slowly rejuvenated. Heavily pruned, overgrown bushes take a few years to rebound, but your efforts pay off in the long run with many years of terrific production after the plants are regularly pruned.

Rejuvenating old, overgrown blueberries means cutting the oldest branches all the way back down to the ground. This initiates new shoots from the root.

Pruning blueberries is emotional

There’s no doubt that pruning blueberries is an emotionally taxing job. It’s particularly difficult to see all the buds being cutting off. But, don’t feel guilty about removing branches with potential fruit. If your goal is to increase your blueberry’s long-term productivity and grow larger fruits, then pruning properly is a must. Just have some wine on-hand for after the job is complete!

Blueberry pruning is an annual chore. Mark your calendar so you don’t forget!

After pruning, blueberry bushes have an open habit and fewer old, woody stems..

Post-pruning fertilization

When spring arrives, here’s how to fertilize pruned blueberry bushes to adjust the soil pH or add an acid-specific organic granular fertilizer, such as HollyTone. Then, mulch the bushes with one to two inches of pine straw, shredded hardwood bark, or shredded leaves. Do not over-mulch. Blueberries have shallow, fibrous root systems that resent thick layers of mulch.

By following these blueberry pruning instructions, you’ll have productive plants for years to come!

For more on growing backyard fruit, check out these articles:

Do you grow blueberries? Which varieties are your favorites?

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Pruning garden blueberries

CategoriesGrowing blueberries By golubika.by

Should blueberries be cut?

Tall blueberry bushes are pruned regularly.

Medium pruning at the beginning of year 3 to encourage strong growth. Fruiting plants are pruned so as to obtain evenly and well-spaced flower buds on them: low-lying branches and weak shoots are removed.

Weak, diseased branches are systematically removed, and healthy branches are left, which will give good growth and yield. Pinch long-bearing shoots, leave 4-6 flower buds on them to enlarge the berries. nine0003

Large stems are kept in the bush for 4-6 years and then cut at ground level without leaving a stump.

At the end of summer pinch off the tops of strongly growing shoots. Remove also bunches of small branches at the ends of the shoots.

To prevent the appearance of diseases, after pruning in the spring, and in the autumn after harvesting, the plants are sprayed with fungicides (topsin, euparen and others) at a concentration of 0.2-0.3%.

Annual pruning plan from year 4 blueberries:

1) it is necessary to cut low spreading branches near the ground, keeping only upright growths; There should be at least five annual shoots.

2) if the middle of the bush is dense, then weak and very old branches should be cut out inside it;

3) most of the small thin branches are removed, leaving strong skeletal branches and shoots. Of the annual shoots, it is desirable to leave the 5 strongest.

Blueberries bear fruit on the growth of the previous year. The degree of pruning also depends on the intensity of shoot growth. If the variety is prone to strong shoot formation like Rancocas, then pruning should be done strong. nine0003

When should blueberries be pruned?

Blueberries should be pruned early in spring (March, early April), before bud break. It is better to remove cut branches (shoots) from the site and burn them in order to prevent the development of diseases and pests on them after winter, which can cause infection for blueberry bushes.

Old shoots must be constantly replaced by new ones, so blueberries should be rejuvenated from 5-6 years of age. nine0003

From young plants, shoots damaged by frost, as well as low-lying, creeping on the ground, are removed.

When a blueberry bush reaches 5 years of age, it is necessary to thin out the bush to enhance its growth and ensure a constant yield.

Thinning accelerates the development of strong annual shoots and ensures a regular harvest. For thinning blueberry bushes, it is necessary to remove old shoots (4-5 years old) and regulate the number of young ones. nine0003

Young shoots with many flower buds should be reduced by one third.

In the first year after planting, flowers are removed from blueberry bushes - this is done in order to influence the proper development of plants. Young blueberry bushes need to be pruned harder as this encourages plant growth.

The maximum yield of blueberry bushes is reached in the 5-6th year after planting in the garden.

In fruit-bearing blueberry bushes, the oldest shoots are pruned to thin out the crown. Sick, damaged, and highly branched shoots at the bottom of the bush are also pruned. nine0003

Blueberry bushes should not be too dense and shoots no older than 4 years should prevail.

Depending on the variety of blueberries, different types of pruning are performed:

- pruning of long shoots of bushes of fast-growing varieties that bend down to the ground.

- in strongly bushy varieties, the whole is cut off, you need to carefully clean the base of the bush from all small shoots.

- Blueberry varieties with a more elongated structure should be pruned more strongly to stimulate their growth. nine0003

- in blueberry varieties with a dense bush structure, it is necessary to shorten shoots that are too branched.

- high-yielding blueberry varieties with a large number of shoots require thinning of the crown.

It is necessary to cut the shoots and branches directed inside the bush, thereby freeing the crown of the bush from thickening.

Blueberry pruning, including spring, plant formation scheme, photo and video

Blueberry is a crop that tolerates pruning very well. Gardeners remove excess shoots even in summer. A bush growing on its own produces many small berries, and as a result of formation and thinning, it produces the same number of kilograms of fruits, but they are large, which means they have more juicy and tasty pulp. nine0003

Contents

Do blueberries need pruning

Removing old, diseased, broken, thickening shoots is a must for any fruit crop. Blueberries run wild without pruning: overgrown with many weak branches, juices are spent on their growth, as a result, the berries grow small and tasteless. In addition, in thickened, windproof plantings with a mass of dead wood, pathogenic fungi accumulate, which lead to rotting of leaves, shoots and roots. nine0003

Unpruned blueberries: many dry, bare branches, leaves showing signs of a fungal disease

When to prune blueberries

Sanitary pruning is carried out all year round, forming - during the deep sleep of blueberries, that is, from late autumn to early spring, when there is no sap flow. As for the age of the bush, traditionally and erroneously, pruning is started in the third year after planting. There are frequent cases when 6–7-year-old bushes begin to thin out for the first time. Foreign experts recommend starting the formation of blueberries at the stage when the seedling is still in the container. nine0006

How to prune a seedling in a container

Pruning in a container is needed if the volume of the above-ground part clearly exceeds the volume of the earth clod in the container, that is, the roots do not have time and are not able to grow in proportion to the crown. If you bought such a bush, then before planting, remove all short branched growths that come out of the ground.

The seedling at the bottom has grown bushy growths that need to be removed

Only powerful vertically directed shoots should remain. They need to be shortened by a third or even half. In this way, you will achieve a balance between the above and below ground parts of the bush. After planting, the cropped crown will take a minimum of juice, the root system will begin to actively develop and give new strong branches. nine0003

Regular blueberry seedlings: 2 strong upright shoots plus small growth without branching; root and aerial part developed in proportion to

Pruning blueberries in the first 2 years after planting

Before fruiting, blueberries are pruned in order to accelerate the formation of a powerful bush. If the seedlings are left unattended for 1-2 years, then many short and branched shoots will grow from the ground, and flower buds will be laid on the tops of tall and strong ones. All juices will be directed to the formation of the first fruits. But a bush thickened with weak and short branches will give a very modest harvest. In addition, he will not be able to resist diseases, frosts, pests. nine0003

That is why in professional gardens, where the berry is grown for sale, that is, large and beautiful, formative pruning is carried out from the first year of planting. To do this, all bushy growths and branches of the second order are removed in such a way that there is no branching up to the knee height (30–40 cm above the ground), but only even vertical stems. And also cut off the tops of strong shoots to remove parts of the plant with flower buds.

There are two types of buds on the branches of fruit crops: small ones, from which leaves grow, and larger ones - flower or fruit, they are usually located on the tops of the shoots. nine0003

As a result of such pruning in young seedlings, fruiting is pushed back and a strong bush is formed, consisting exclusively of powerful and productive stems.

Video: summer pruning of young blueberries

Phytosanitary blueberry pruning

The event is held regularly throughout the season and with blueberries of any age. In spring, frozen tops are removed, in summer - young still green growths damaged by insects and hail. Pruning is carried out, capturing 1-2 cm of a healthy area. nine0005 Any wound on a plant is a gateway to various diseases. Fungi grow inside soft and succulent tissues and cannot attach themselves to smooth, undamaged branches. By cutting off the problematic parts of the plant, you destroy the foci of infection and give the bush the strength to form new and healthy stems and twigs.

A hailstone on a vine shoot: soft tissues are exposed, the leaf receives little nutrition, signs of disease are visible

Before and after trimming, disinfect tools by wiping blades with alcohol. Treat the entire plant with a fungicide, for example, Bordeaux liquid, Skor preparation and others. During the fruiting period, you can spray Fitosporin. nine0003

Mature pruning

3-4 years after planting, remove from a well-formed and fruit-bearing bush: