Vaccinium
Common Name: Northern Highbush Blueberry
Overview
| Plant Type | Perennial |
| Hardiness Zone | 4-8 |
Blueberries are very attractive landscape plants with beautiful fall foliage colors. They seem relatively slow to come into their mature fruitful size, which for northern Highbush blueberries can be 6'-8' in height and six years of age. Although blueberry plants are sold in numerous local nurseries and by catalog nurseries, they are a very challenging fruit for the Ohio gardener. The single greatest growing challenge is their love and absolute need for extremely acidic soil pH, preferring 4.5 to 4.8!
Cultivars
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Cultivar |
Height |
Spread |
Blooms |
Sun |
Planted |
Comments |
| Bluecrop Vaccinium corymbosum | 5-6’ | 3-4’ | n/a | Full sun | Berry garden |
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| Jersey Vaccinium corymbosum | 4-6’ | 2-3’ | n/a | Full sun | Berry garden |
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Getting Started
Blueberries grow naturally in sandy to loam soil with a pH between 4.5 and 5.2. The soil must be moist, yet well-drained during most of the growing season. These requirements present challenges for Ohio gardeners with the state's prominence of heavy clay soils.
One solution is raised beds filled with an appropriate mix of growing media to provide the desired acidity and drainage. Mix native soil with peat moss or other composted organic matter in a ratio of three parts soil to one part organic matter. Be sure to take a soil sample One solution is raised beds filled with an appropriate mix of growing media to provide the desired acidity and drainage. Mix native soil with peat moss or other composted organic matter in a ratio of three parts soil to one part organic matter. Be sure to take a soil sample and send it to be tested at a qualified soil testing facility. Follow any recommendations made or apply any amendments to the soil in the fall previous to planting the blueberries. Eliminate any guesswork regarding existing soil nutrients or any lack thereof, and determine the trends of the soil pH to move up, down or remain the same. Always take a soil sample and use the soil test as a guide before applying any lime, sulfur or fertilizers.
Plant two varieties for cross-pollination and greater plant productivity. Space plants about four feet apart, except for ‘Berkeley,’ which should be planted five feet apart.
Another option is to grow blueberries in containers filled with an acidic soil mix (e.g., an azalea soil mix). Several dwarf varieties are especially well suited for container gardening.
Selection of Cultivars
There are multiple types of blueberries, including, rabbiteye, southern highbush, northern highbush, lowbush and half-high (northern highbush x lowbush) hybrids. Only northern highbush and half-high blueberries are recommended for growing in Ohio. A list of specific named cultivars is found in Fact Sheet HYG-1422, Growing Blueberries in the Home Garden.
Planting Bare Root Plants
From Burpee's guide, Learn About Blueberries.
- Dig each hole twice the size of the root mass.
- Keep the crowns above the soil level. Plant into the hole and back fill with loose soil. Gently press soil in around the root ball. Transplants need good root-to-soil contact. Do not press too hard because that can cause soil compaction and root damage.
- Gently water around the root ball to settle the soil and drive out air pockets.
- After planting be sure to mark the plants with plant labels so you know where they are and what varieties they are.
- Mulch with 2-3 inches of compost of pine needles to retain moisture and prohibit weed growth.
Ongoing Management
See also, Burpee's instructions in the published articles below.
Weed Control & Mulching
Mulch 2-3” to help with water retention, and to protect the roots for Winter.
Insect & Disease Control
Several insects can cause damage to blueberries. They include spotted wing drosophila, blueberry tip borer, plum curculio, cranberry fruit worm and cherry fruit worm.
In addition, blueberries are susceptible to several diseases, including mummy berry, powdery mildew, twig blights, botrytis blossom blight, leaf spots and cane gall. Sanitation, proper siting, and chemicals labeled for the problem and the crop provide adequate control.
Fertilization
To fertilize blueberries, use an acidifying fertilizer like ammonium sulfate, and regularly apply it to the planting. Suitable fertilizers include elemental sulfur, aluminum sulfate or products recommended for camellias, azaleas or rhododendrons. Manures are not recommended to fertilize blueberries because they are alkaline.
Watering
A 3" - 4" layer of wood chip mulch will maintain appropriate soil moisture levels and prevent weeds. Because of blueberries' shallow root system, hand pull weeds instead of tilling or hoeing. Supplemental watering is also important to produce a satisfactory harvest.
pH Management
Blueberries need a pH of 4.5 - 5.2, but it should be closer to 4.5.
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Culture
The first year, remove blossoms to stimulate and invigorate vegetative growth and consequently root production. In addition, prune young bare-root plants by removing any broken canes, damaged canes and small side branches. Cut back the top third of the remaining single stem canes. In the next couple years, continue to remove any damaged or crossing canes. In the fourth year, begin selective pruning which involves removing one-third of the oldest stems and cutting out any dead wood, crossing canes, weak or spindly branches and suckers.
As fruit is developing, sizing and ripening, the plants require 1-1 ½” of water, whether by precipitation or supplemental watering. The use of drip irrigation or soaker hoses is an extremely economical way to water plants and does not cause unnecessary leaf wetness and humidity around the planting.
Before harvesting the berries, taste a few to check for ripeness. Some cultivars have berries that appear to be the correct deep blue color for ripeness but are still quite tart and not fully ripe. Also, there are some pink-colored blueberries now on the market.
Pruning / Cutting Back
Annual pruning of healthy blueberry bushes ensures stable yields of fruit year to year and helps eliminate pests and diseases.
There will be no need to prune in the first couple of years. Instead, rub off the fruit buds to promote vegetative growth. You can also prune the tips of the shoots when the flower buds appear.
Prune in early spring of the third year - waiting until after the harvest can make the bushes susceptible to injury in winter's cold. Trim away dead branches without fruiting buds, down to the base of the plant. Keep a half dozen or so fruit-bearing canes per bush.
Blueberries are bred for pest and disease resistance, but if you have a good site and quality plants and still encounter problems, try a little extra TLC with a blanket of mulch. Promptly trim away diseased branches and be sure to wipe down the pruners between cuts.
Tip: Keep your pruners clean between cuts with alcohol wipes or a spray of Lysol. This will keep diseases from spreading.
The book noted below, Pruning Simplified (pgs 138-139), is also a good read regarding the pruning of this bush.
From Gary Gao:
- The redish canes produce the most fruit. Prune the other canes.
- Focus on removing the angled or horizontal canes. After pruning, the vertical canes should be remaining.
- Remove canes growing towards the center.
- Plan to remove ~50% of the bush.
See also:
- Fact Sheet HYG-1430, Pruning Blueberries in the Home Garden (from OSU), and
- Pruning a Blueberry Bush for Big Bountiful Harvests (from Burpee).
Integrated Pest & Pollinator Mgmt Notes
Several insects can cause damage to blueberries. They include spotted wing drosophila, blueberry tip borer, plum curculio, cranberry fruit worm and cherry fruit worm.
In addition, blueberries are susceptible to several diseases, including mummy berry, powdery mildew, twig blights, botrytis blossom blight, leaf spots and cane gall. Sanitation, proper siting, and chemicals labeled for the problem and the crop provide adequate control.
Harvesting
You'll know that blueberries are ripe when they are plump and colored a deep blue with a dusting of gray. Any hint of red means the berry is still tart and not yet sweet. White and green colored blueberries, while beautiful, are not ripe and need more time on the bush. Blueberries with a bit of red or purple will ripen at room temperature after they are picked.
When grown organically, you can eat blueberries out of hand, right off the bush.
Blueberries also freeze well. Spread out unwashed berries (washing removes the waxy bloom that protects the berries) on a sheet pan and freeze overnight. Place frozen berries in containers or freezer bags, label and tuck away to be enjoyed later.
Pollination Needs
The Bluecrop cultivar does not require pollination; however it is beneficial.
Winterisation
The roots are shallow, so protect them for Winter.
More Information
Published Articles
- Burpee
Books and Papers
- Growing Blueberries in the Home Garden (Fact Sheet HYG-1422), from The Ohio State University Extension
- Pruning Blueberries in the Home Garden (Fact Sheet HYG-1430), from The Ohio State University Extension
- Controlling Diseases and Insects in Home Fruit Plantings, by Dr. Celeste Welty and Dr. Michael A. Ellis, The Ohio State University
- Midwest Blueberry Production Guide, edited by Nicole Ward Gauthier and Cheryl Kaiser, Department of Plant Pathology, University of Kentucky
- Midwest Fruit Pest Management Guide, by the Midwest Fruit Workers Group
- Midwest Home Fruit Production Guide, by the Ohio State University
- Pruning Simplified: a Visual Guide to 50 Trees and Shrubs, by Steven Bradley.
Web Sites
- Gardenia.net
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