Growing blueberries at home can be a challenge, but they are so delicious when homegrown, it is definitely worth the effort! Blueberry plants come in two main types: highbush and lowbush. Highbush blueberries (Vaccinium corymbosum) grow in a wider geographic range than lowbush, and they are a common choice for home gardeners.
I. Appearance and Characteristics
Vaccinium corymbosum, the northern highbush blueberry, is a North American species of blueberry. Other common names include blue huckleberry, tall huckleberry, swamp huckleberry, high blueberry, and swamp blueberry.
Vaccinium corymbosum is a deciduous shrub growing to 1.8–3.7 metres (6–12 ft) tall and wide. It is often found in dense thickets. The dark glossy green leaves are elliptical and up to 5 centimetres (2 in) long. In autumn, the leaves turn to a brilliant red, orange, yellow, and/or purple.
The flowers are long bell- or urn-shaped white to very light pink, 8.5 of an millimetres (1⁄3 in) long. The fruit is a blue-black berry with a 6.4-to-12.7 mm (1⁄4-to-1⁄2 in) diameter.
The species is tetraploid and does not self-pollinate. Most cultivars have a chilling requirement greater than 800 hours. Cytology is 2n = 48.
It is native to eastern Canada and the eastern and southern United States, from Ontario east to Nova Scotia and south as far as Florida and eastern Texas. It is also naturalized in other places including Europe, Japan, New Zealand, and the North American Pacific Northwest.
The plant is found in wooded or open habitats with moist acidic soils.
II. How to Grow and Care
Sunlight
The highbush blueberry is a full sun plant. Insufficient sunlight affects its flowering and fruiting. When selecting a growing location, try to avoid placing your plants near large trees. The tree crown coverage not only affects light, but also reduces air circulation, making diseases much more likely.
Temperature
The highbush blueberry has many cultivated species that have a wide adaptability to different temperatures. However, cold temperatures (T < 7 ℃) during dormancy are vital to helping them bloom the following year. The Lowbush Blueberry and the Northern High Blueberry usually need more than 800 to 1000 chill hours in an environment below 7 ℃. The Rabbiteye highbush blueberry from the south also needs around 350 to 700 hours. It is important to pay attention to cold resistance and chill hours when selecting varieties.
The highbush blueberry has a fibrous root system with shallow root distribution. Like other Ericaceae species, its roots with symbiotic fungi absorb water and nutrients from the soil. Therefore, the highbush blueberry is neither drought-resistant nor flood-resistant, and requires careful adjustment of soil moisture.
Watering
Thriving in its native moist, acidic soils of Eastern North America, highbush blueberry is well-adapted to environments with consistent moisture. This species exhibits a preference for evenly moist conditions and demonstrates moderate drought tolerance once established. For optimal health, watering once every 1-2 weeks is recommended to mimic the natural hydration rhythm. Typically grown outdoors due to their size and need for pollination, highbush blueberry benefits greatly from mulching which helps retain soil moisture, especially important during its active growing season.
Soil
Because the wild blueberries mostly grows on the edges of forests, they are accustomed to the acidic soil formed by dead branches and fallen leaves.Loose, acid soil (pH 3.8-5.5) with a good drainage performance and plenty of humus is best, with the optimum pH value being 4.5. Sandy soil and sandy loam are also preferred.
Soil acidity can be adjusted to cater to the highbush blueberry. If the pH of your soil is between 5.5 and 7.0, sphagnum peat can be applied at a 10 to 15 cm thickness into the 0 to 150 mm top-layer of soil, before being fully mixed in.
Sphagnum peat not only improves soil acidity, but also significantly increases the content of humus. If the pH of your soil is higher than 7.0, a raised ridge bed can be built and filled with soil that has the correct acidity. Back-filling soil should be 20 to 30 cm higher than the ground plane, and all roots must be covered in the soil layer below 0 to 150 mm.
Fertilizing
Highbush blueberry thrives with balanced fertilizers, such as 10-10-10. Apply in early spring at bud-break and repeat mid-season. Use 1 ounce per foot of shrub height, avoiding over-fertilization to prevent root burn. Benefits include robust growth, improved fruit yield, and enhanced plant health. Seasonal adjustments are key: reduce quantity in dormant periods. Ensure even distribution at the drip line for optimal uptake. Soil pH, around 4.5-5.5, influences nutrient availability; adjust as necessary. Wear gloves, keep granules off foliage, and water thoroughly post-application.
Pruning
Pruning of young plants: After planting, for the first two or three years, the flower buds should be completely removed in the spring. This will promote growth, improve lifespan and boost future fruit yield. Pinch off any spindly shoots during the growing season to increase the number of sprouting lateral branches, so as to expand the tree crown.
Fruiting plant pruning: From the third year after planting, the highbush blueberry should be pruned each year, before the sprouting of new buds in early spring. The annual branch bears fruits, and the stronger the branch is, the more fruits it bears. For mature plants, each cluster should retain 4 to 6 stems and 1 or 2 new branches each year, keeping the tree uniform and well-ventilated.
Because of the plant’s slow growth, pruning should be conservative. Excessive pruning will greatly affect the amount of fruits produced. Highbush blueberry has both creeping and erect branches, and the erect should be retained as much as possible when pruning.
Propagation
Highbush blueberry is effectively propagated using cuttings, offering a reliable method to ensure genetic consistency in new plants. Semi-hardwood cuttings taken from healthy, disease-free parent plants can promote successful rooting. Pre-treatment with rooting hormones may enhance the chances of success, followed by placing the cuttings in a well-draining medium to foster growth. Proper moisture and temperature management are crucial for rooting, as is protection from direct sunlight during the initial stages.
Transplanting
For the best results, transplant highbush blueberry during the rejuvenating period of early spring. Choose a sunny or partially-shaded location with well-draining, acidic soil. To enhance transplant success, ensure the root ball remains intact and well-hydrated throughout the process. Happy gardening!
Repotting
Highbush blueberry, a bushy shrub, thrives when repotted every 2-3 years, ideally during late winter before spring growth. Select a container that is 2-4 inches wider than the root ball to encourage expansive growth. Post-repotting, use acidic soil mix and ensure consistent moisture without overwatering. A partially sunlit spot and monthly fertilization will facilitate highbush blueberry’s optimal recovery and berry production.
Pests and Diseases
Common Pests
Birds and deer are big fans of blueberries of all varieties. Read more in our growing guide for tips to protect your blueberry harvest from hungry herbivores.
In addition to insect pests like maggots, beetles, and caterpillars, highbush blueberries are sometimes attacked by blueberry tip borers.
The larvae of Hendecaneura shawiana hatches in late spring as the new growth starts to harden on plants.
The caterpillars burrow into the canes, chewing up to a foot down the cane by the time winter arrives. They cause new shoots to wilt or arch, and the leaves may turn yellow with red veins.
Prune infected canes to get rid of them. If you notice damage on your plants, cut the affected cane at least a foot down, or trim it away altogether.
Common Diseases
Keep an eye out for the following diseases.
There are no cultivars available that are resistant to everything, and not all diseases occur in all areas, so you might want to check with your local agricultural extension office to find out what to grow in your area to avoid problems.
- Blueberry Mosaic
Blueberry mosaic (BlMaV) is thought to have existed in native plants for centuries. It causes plant growth to become stunted and you’ll see the leaves start to turn yellow, pink, or mottled.
While most varieties are resistant, it does impact a few different cultivars. Since there is no cure for this virus, you must pull infected plants and destroy them.
- Blueberry Shock Virus
Blueberry shock virus (BIShV) is common in the Pacific Northwest. It causes blossoms and flowers to die off rapidly during the blooming period.
The foliage will return, but the plant won’t fruit. After a few years, the plant will return to normal, though the virus remains in the tissue.
It’s carried from plant to plant by pollinators and infection sets in when plants are in bloom. Avoid susceptible cultivars and buy certified virus-free seeds or plants.
In the home garden, there isn’t much you can do but let the disease run its course. Commercial operations are often forced to cull plants and start anew so it doesn’t spread.
You can do this, but since the plants will continue producing as normal, you may opt to just live with it.
- Chlorosis
Not technically a disease, but rather a physiological disorder caused by a nutrient deficiency, chlorosis occurs when the plant doesn’t receive enough iron and the leaves can’t produce chlorophyll.
You’ll often see yellow or discolored foliage and the plant may be stunted. Leaves may also drop prematurely.
It isn’t necessarily that there isn’t enough iron in the soil, but rather, your plants may be unable to access it because the soil is too alkaline. Anything above a pH of 6.0 may cause a problem.
In the short term, you can spray plants with chelated iron, which you can purchase at your local garden supply store or online.
Follow the manufacturer’s recommendations. In the long term, you may need to add sulfur or iron sulfate to the soil to make it more acidic.
You should also add a layer of sawdust mulch to protect the roots from overheating if you live in an area with temperatures that reach above 85°F.
Stressors like excessive heat reduce root growth and can also cause plants to have difficulty accessing iron in the soil.
- Ripe Rot
Ripe rot, sometimes called anthracnose fruit rot, has been devastating to some orchards in the Pacific Northwest.
It’s caused by a fungus called Colletotrichum acutatum, which favors warm, moist conditions. It’s spread by water, whether that’s in the form of rain, humidity, or irrigation.
The first thing you’ll notice is a darkening of new shoot tips, followed by flowers that start to turn brown or black. You may eventually see pink spores on infected berries.
You might miss the pink spores on the plant, but you’re sure to notice them when you harvest the fruit.
Spores are picked up by your hands or tools like clippers and will spread rapidly as you pluck the fruit and move from bush to bush.
Your best defense is to try to improve air circulation and reduce wetness on plants. Don’t water from overhead and keep your plants pruned well.
Make sure to keep bushes spaced well when you plant. You can also use a copper-based fungicide treatment, according to the manufacturer’s directions.
III. Uses and Benefits
- Ornamental uses
If you’re looking for a plant to attract animals to your garden, highbush blueberry is a great choice. Its flowers are mainly pollinated by bees, and birds and mammals are attracted to its fruit. This plant has ornamental appeal for its flowers and berries, and it can be grown in the borders and beds of informal and cottage gardens. This plant grows well with rhododendrons and azaleas.
- Culinary uses
Many of us are sure to love them as a topping on yogurt or oatmeal for breakfast, or as a treat on ice cream or meringues for dessert, but don’t forget that they’re delicious in savory dishes as well!
You can make a sauce using fresh berries that is delicious as a topping on meat or fish. Or put them on soft brie on top of a slice of toast.
Try making blueberry kefir at home, a tasty probiotic beverage.
IV. Harvesting and Storage
Highbush blueberries are the earliest species to start ripening, and some are ready to start plucking as early as April in some areas.
Under ideal conditions, with the right soil, water, weather, and minimal damage from pests and diseases, a single bush can produce nearly 20 pounds of berries. Plants can continue to produce for up to 50 years.
Let the berries ripen fully on the plant before picking them.
How will you know that it’s time? If you tug a berry, it should come away readily. Look at the fruit stem; it should be blue, not red or green. The berries should also be matte or dull, not shiny.
Berries growing in a cluster will ripen unevenly, so some will be ready to go and others may need another few days to a week. Pick the individual berries by hand and gently place them in a bucket or basket. Berries taste incredible right off the bush when they are warm from the sunshine, but if you don’t plan on eating them right away, stick them in a cool area or in the refrigerator. This helps to improve their shelf life. Don’t wash the fruits until you are ready to dig in.
