How to Grow and Harvest Blueberries

Blueberry bushes are easy to grow with a slow to moderate growth rate. Blueberries can be planted directly in the ground, form landscape shrubs in your yard, or grow in pots to add a pop of color to your patio. Sizes range from one to eight feet tall and two to 10 feet wide, depending on the species.

Blueberries include several species of flowering, fruiting shrubs within the Vaccinium genus, all native to North America. Relatives within the Vaccinium genus include the bilberry, cranberry, huckleberry, and lingonberry.

Blueberry bushes have pointed, oblong leaves that are leathery to the touch and turn a brilliant red color in the fall. The flowers appear in clusters of small, white, bell-shaped blooms in the late spring, leading to deliciously edible berries that ripen from green to a deep purple-blue.

Quick Tips

• Start growing blueberries in early spring in full sun and acidic soil.
• Expect at least three growing seasons before a moderate harvest; a more meaningful harvest comes after six years.
• Cultivated berries usually have higher yields and more heat and cold tolerance; wild berries generally are smaller but often sweeter.

How to Plant Blueberry Bushes

When to Plant

When selecting blueberry bushes, the best choice is bare-root two- to three-year-old plants. Older plants suffer more transplant shock and will take a few years to begin producing large harvests.

Blueberry bushes are generally planted in the early to mid spring. In USDA hardiness zones 6 and higher, they also can be planted in the late fall.

Where Blueberries Grow Best

Pick a spot that receives full sun but is sheltered from strong winds. Avoid a planting site close to tall trees or shrubs that might block the sunlight or compete for soil moisture and nutrients.Make sure the planting site has good soil drainage.

You can mix some peat moss into your planting hole to keep the soil loose, acidic, and well-drained. Blueberries can also be grown in containers with sufficient sunlight and moisture.

Spacing, Depth, and Support

Blueberry bushes should be spaced in a row about four to five feet apart; adjacent rows should be spaced nine to ten feet apart to provide plenty of room for harvesting.

For bare-root plants, spread the roots out into a prepared hole, then cover them with soil and ensure the root ball is no more than 1/2 inch below the soil surface.

For container-grown blueberries, plant them at the same depth that they were in the nursery pot. Blueberry bushes are sturdy plants and generally don't need any support structure.

Blueberry Plant Care

Light

Blueberry plants need full sun to grow and fruit well. This means at least six to eight hours of direct sunlight on most days.

Soil

Blueberries should be grown in very acidic soil with a pH of 4.0 to 5.2. They also grow best in soil that's rich in organic matter. If your garden has heavy clay soil, blueberries will fare better in raised beds where you can control the soil composition and pH. Sandy soil is preferable to dense clay.

Add a layer of mulch after planting: Evergreen wood chips, sawdust, and pine needles will help to keep the soil acidic. To get the proper soil pH for growing blueberries, it's best to amend the soil the season before planting.

Yellow Leaves?

It's common for blueberry leaves to begin to yellow. This likely indicates that thesoil pHis too high, and the blueberry plants cannot access available iron. If you see yellowing leaves worsening, have the soil pH tested and make adjustments as necessary.

Water

Be sure the plants get deep wateringat least once per week. Blueberries are shallow-rooted and need at least a couple of inches of water each week (more during dry spells). You can also utilize an automatic irrigation system to ensure consistent water for your plants.

Temperature and Humidity

The temperature requirements of blueberry bushes vary according to the species. The traditional highbush types prefer humid air and a cold winter climate, but variants bred for southern gardens do not tolerate freezing temperatures. Most types prefer protection from drying winds.

Fertilizer

Don’t fertilize your blueberries in their first year. Once your blueberries have been planted for one year, you can begin feeding them based on two main indicators: when the flower buds first open, then again when berries start to form.

Remove weeds regularly to ensure soil nutrients are not consumed by weeds. You can use any fertilizer for acid-loving plants, including blueberry food and azalea food.

Gardeners can either make foliar applications (applying directly to the leaves) or fertilize the soil, and many choose to use organic fertilizers like fish emulsion, compost, or manure tea.

Pollination

Blueberries can self-pollinate. However, for best results, plant two or more bushes—two is good, but three is better. The diversity will result in a higher fruit yield and larger fruits. Ensure the varieties you choose bloom simultaneously to ensure cross-pollination between the plants occurs.

Types of Blueberries

There are four main types of blueberry plants: highbush, lowbush, half-high, and rabbiteye. Their size primarily classifies them, and plant breeders continue cultivating new varieties to improve their vigor. The main types include:

• Highbush (V. corymbosum) is a roughly six-foot shrub hardy in zones 4 through 7. This is the most common and productive type of blueberry. Varieties suitable for cold winters include 'Bluecrop,' 'Blueray,' 'Herbert,' 'Jersey,' and'Meader.' Types known for big berries include 'Berkeley,' 'Bluecrop,' 'Blueray,' 'Coville,' 'Darrow,' and'Herbert,' and a variety produces pink berries called 'Pink Lemonade.'
• Southernhighbush(hybrids ofV. virgatum,V. corymbosum, orV. darrowii) is considered somewhat hard to grow, but several cultivars are popular for Southern gardens, including 'Emerald,' 'Windsor,' and'Springhigh,' These are shorter, three- to six-foot-tall bushes with a four- to five-foot spread. They are grown in zones 7 through 10.
• Lowbush (V.angustifolium) are bushes well suited for the coldest climates, as far north as zone three. They have a much different growth habit from other types, growing about one foot tall with a creeping spread. Native to the northeast United States and southern Canada, the berries have a waxy covering that makes the fruit look gray. These are sometimes considered wild blueberries.
• Half-high blueberries (hybrid of V. corymbosum and V.angustifolium) are a newer breeding development, including varieties developed by crossing highbush and lowbush species. Most of these grow 18 to 48 inches high. Popular cultivars include 'North Country,' 'Northblue,' and 'Northland.' The berries are typically less sweet than highbush blueberries, but they work well in pies, jams, and preserves.
• Rabbiteye (V. virgatum) was previously categorized as V. ashei. It isgrown mainly in the southeastern U.S. Growing as high as 15 feet, it requires two or more varieties to pollinate correctly. Recommended types include 'Powderblue,' 'Woodard,'and 'Brightwell,' 'Delite,' which is another good late-bearing variety. Rabbiteye blueberries are excellent choices for gardens in zones 7 through 9.

Blueberries vs. Huckleberries

Blueberries and huckleberries come from the same genus. The fruits look similar at first glance: they’re both small and round with a blueish color. However, huckleberries tend to be tarter than blueberries, and their seeds are noticeably hard when you bite into them (unlike blueberry seeds).

Harvesting Blueberries

Blueberries will typically be ready to harvest between June and August. Most blueberry plants won’t produce fully until about their sixth year. Mature blueberry bushes yield around eight quarts of berries per bush. Extending your blueberry harvest is possible by planting two or more bushes, such as early-, mid-, and late-season varieties.

The only reliable way to know whether blueberries are ready to pick is to taste them. Ripe blueberries will readily come off the stem. Blueberries are their sweetest if allowed to stay on the plant for at least a week after turning blue. Hold a container under berry clusters, then gently pick them off with your other hand to drop the fruits into the container.

Put them in the refrigerator, unwashed as soon as possible. They typically can keep up to a week when refrigerated (wash them before use). The berries can be eaten fresh or used in baked goods, and they also can be frozen and kept in the freezer for around 6 to 12 months.

Growing Blueberries in Pots

Blueberries are one of the easiest berries to grow in containers. They are popular in home gardens because they can grow in small spaces, including containers. Containers are especially ideal if you don't have adequate soil conditions for blueberries.

Use a container at least 18 inches deep with ample drainage holes. An unglazed clay pot is ideal because it will allow excess soil moisture to escape through its walls.

Use one container per plant and choose a blueberry variety that remains relatively small. Select a potting mix made especially for acid-loving plants, then plant your blueberries at the same depth they were in the nursery pots.

Keep the soil lightly moist but never soggy, and make sure the container gets plenty of sunlight. Use a fertilizer made for acid-loving plants in the spring.

Pruning

Blueberries will continue producing at their best with some maintenance pruning. In the first two years, remove any flowers to help your plants grow more vigorously. You can leave the flowers on for the third year. They won't produce manyberries, but no pruning is necessary until the fourth year.

Beginning in the fourth year, prune your blueberry bushes in late winter or early spring while they are still dormant. A good rule of thumb is to prune about 1/3 of the plant to encourage new growth.

Using clean, sharp garden shears or a small wood saw, remove any dead, broken, crossed, or weak branches where they meet the main stem. The goal is to open up the bush so light can reach the middle, so it's also important to trim any branches that cross each other.

Maintenance pruning in subsequent years should aim at thinning out the older branches. Cut back the oldest branches to near ground level, then prune back branches that have growntoolong or too thin. Older branches will look gray; newer branches will have more of a reddish tinge.

Propagating Blueberries

Like many woody shrubs, blueberries can be propagated by rooting cuttings from softwood or hardwood. Not only is this a cost-effective way to get a new plant, but it also helps to thin out mature plants.

The best time to take softwood cuttings is in the early spring, while hardwood cuttings are best taken in late winter before new growth begins. Here's how:

1. Choose a healthy branch. Use pruners to cut off the last five inches of growth from the tip of the branch, then remove all but the top two or three leaves.
2. Apply a rooting hormone to the cut end.
3. Plant the cutting in a moistened soilless potting mix in a small container, and place the container in a warm room that isn't exposed to drafts or temperature fluctuations.
4. Keep the container in bright, indirect light, and make sure the growing medium stays moist but not soggy. It can take a few months for the cutting to root.
5. Once new leaves have developed and you feel resistance when gently tugging on the cutting (indicating that it has grown roots), it is ready to be planted in the garden. For hardwood cuttings, wait until spring to transplant outdoors.

How to Grow Blueberries From Seed

Before planting blueberry seeds, they must first be put in the freezer for 90 days to mimic the winter cooling period.

You can grow blueberries from fruit by freezing them, then mashing them or putting them in a blender or food grinder. Once macerated, the seeds sink to the bottom. Collect the seeds by separating them from the juice and pulp.

Fall is the best time to plant seeds in warm climates, while spring is best in cool climates. Fill a flat tray with moistened sphagnum moss, sprinkle the seeds on top, then lightly cover them with more moss. Cover the tray with newspaper and place it in a room between 60 and 70 degrees. Keep the moss consistently moist.

Seedlings should emerge in about amonth, when you can remove the newspaper and keep the tray in bright, indirect light. Once the seedlings are two to three inches tall, they can be planted in an equal mix of peat moss, sand, and soil. They should be large enough to plant in the garden during the spring of their second year after the threat of frost has passed.

Potting and Repotting Blueberries

You should start growing blueberries in as large of a container as possible. If you see roots emerging from drainage holes or the top of your container, it’s time to repot into something larger. Choose a container that comfortably fits the root ball.

Fill your container with fresh potting mix or a soilless medium of equal parts shredded pine bark and sphagnum peat moss. Replant the shrub at the same depth it was in its previous container.Keep the soil moist but not soggy.

Overwintering

Blueberry bushes go dormant over the winter and are generally hardy to the coldest conditions of their hardiness zones.

However, they can be susceptible to fluctuating winter temperatures that trigger new growth. If your blueberries are growing in pots, it's helpful to cover them in frost blankets to minimize freezing air and wind chills.

To protect the bushes in the ground and maintain consistent soil temperatures, add a layer of mulch around them before the weather gets cold.

Common Pests and Plant Diseases

By far, the biggest problem growing blueberries is keeping birds at bay. Placing bird netting over your blueberries or using a scarecrow can be successful if you have only a few bushes. However, if you have a large blueberry patch, consider trying abird deterrent.

Insects to be on the lookout for include: scale, blueberry tip borer, cherryfruit worm, cranberry fruit worm, and plum curculio. Check with your local extension for the prescribed deterrents and treatments if these are common pests in your area.

Some fungal diseases can affect blueberries, includingpowdery mildew, rust (which can be treated with neem oil), and leaf spot diseases.

Your best defense is to plant genetically resistant varieties. It also helps to give your plants plenty of space for goodair circulation, grow them infull sun, clean up any fallen debris, and replace the mulch annually so that fungal spores cannot overwinter in the area.

If you experience these problems, you might need to use a fungicide labeled for use on edible plants. Some other common blueberry diseases to be aware of include:

• Anthracnose:This fungal disease spreads rapidly in damp weather. Symptoms are bright pink clusters of spores on the developing berries.
• Botrytis:Another fungus that thrives in damp conditions,botrytiswill cause the fruit to wither and rot.
• Canker:This disease begins in the lower parts of the canes. You’ll notice small reddish spots that will enlarge into abullseye. If left untreated, they will eventually circle and girdle the cane, causing it to die back.
• Mummy berry: One of the more severe diseases affecting blueberries, it is caused by a fungus. The first sign of an infestation is the blackening of flower clusters, which eventually die. The resulting fruit turns tan and hard, looking like mummified berries.
• Twig blight:Twig blight can start off looking very similar to canker. As twig blight progresses, it can affect the crown, smaller branches, andtwigs and cause leaf spots.

From: thespruce