Blueberries are popular in home gardens because they can grow in a small space, even in containers. In fact, they are one of the easiest berries to grow.
There are three main types of blueberries: highbush, rabbiteye, and southern highbush, as described below. Each has its growing preferences, so be sure to choose the right blueberry for your garden's conditions.
Blueberries are a large species of flowering and fruiting shrubs that are native to North America. Relatives within the Vaccinium genus include the bilberry, cranberry, huckleberry, and lingonberry.
Cultivated blueberries are continually being bred for higher yields, heat and cold tolerance and better pest resistance. Still, some people prefer the blueberries that grow wild in forests and fields. Wild berries are smaller, and it will take you a while to pick enough for a pie, but many people find them the sweetest to eat. Perhaps it’s the result of the plants growing where they’re happy.
- Flowers: Small, white, bell-shaped flowers hang in clusters in late spring.
- Berries: The berries ripen over time, from green to a deep purple-blue.
- Leaves: Leaves are a pointed oblong, oval shape; substantial and almost leathery to the touch. They turn a brilliant, red in the fall.
Botanical Name/Common Name
- Vaccinium corymbosum–Highbush Blueberry
- Vaccinium ashei–Rabbiteye Blueberry
- Vaccinium formosum–Southern Highbush Blueberry
- Highbush–USDA Hardiness Zones 3-7
- Rabbiteye–USDA Hardiness Zones 7-9
- Southern Highbush–USDA Hardiness Zones 7-10
Blueberry plants need full sun to grow and fruit well, and to avoid common diseases.
Mature Plant Size
- Highbush: 8-10 ft. (h) x 6-8 ft. (w)
- Rabbiteye: 15 ft. (h) x 10 ft. (w)
- Southern Highbush: 3-6 ft. (h) x 4-5 ft. (w)
Days to Harvest
Most blueberry plants will start to produce a small harvest by their third year, but won’t begin to produce fully until about their sixth year. Mature blueberry bushes produce about eight quarts of berries per bush.
It’s possible to extend your blueberry harvest by planting early, mid- and late-season varieties, instead of all one variety.
The only reliable way to know if blueberries are ready to pick is to taste one or two. Blueberries are their sweetest if allowed to stay on the plant at least a week after turning blue.
- Soil: Blueberries like very acidic soil, with a soil pH in the rage of 4.0 to 4.5. They also like soil rich in organic matter. If your garden has heavy clay soil, blueberries will fare better in raised beds. To get the right soil pH for growing blueberries, it’s best to amend the soil the season before you intend to plant. Garden sulfur or aluminum sulfur can be mixed into the top 6 inches of soil, to lower the pH as needed. If you have your soil tested at a garden center or your local extension office, they will be able to tell you how much sulfur you’ll need. It’s wise to retest your soil before actually planting, to make sure you’ve achieved the results you were after. Continue amending and tweaking the soil as necessary. Unfortunately, this will be an ongoing task, since soil tends to revert to its original pH.
- Planting: Look for bare-root plants that are 2-3 years old. Older plants suffer more transplant shock and will still take a few years to begin producing large harvests. Plant your blueberries in early spring. You can mix some peat moss into your planting hole, to keep the soil loose, acidic and well-draining. If you have only two or three plants, space them about 4-5 feet apart. To plant rows of blueberries, space plants about 4-5 feet apart in rows that are 9-10 feet apart. Plant blueberries so that the roots are spread out in the hole and completely covered in soil. If they were container grown plants, plant about 1 inch deeper than they were in the pot. Mulch after planting. Evergreen wood chips, like pine or cedar, sawdust, and pine needles will help keep the soil acidified. Be sure the plants get a deep watering at least once per week. Blueberries tend to be shallow-rooted and need at least a couple of inches of water each week, more during dry spells.
- Fertilizers: Don’t fertilize your blueberries in their first year. The roots are sensitive to salt until the plants are established. Ammonium sulfate is usually used as a fertilizer for blueberries, as opposed to the aluminum sulfur used to lower the pH. But you can use any fertilizer for acid-loving plants, including blueberry food and azalea food.
Suggested Varieties to Grow
Plant breeders keep improving the vigor and disease resistance of fruit trees, so it’s hard to recommend varieties without updating them every season. The varieties mentioned here are old favorites. Check with your local Cooperative Extension office for the most current recommendations for your area.
Note: Although blueberries are self-fertile, you will get larger berries and more of them if you have two different cultivars that bloom at the same time to cross-pollinate.
- Highbush (or Northern Highbush): Usually recommended for colder climates. Will self-pollinate, but yield and size are greatly improved with cross-pollination.
- Early: 'Earliblue, 'Collins;' Mid: 'Blueray,' 'Bluecrop,' 'Berkeley;' Late: 'Jersey', 'Patriot.'
- Rabbiteye: Native to the southern U.S. Not self-fertile. It requires two varieties for pollination. This extends the harvest into August, virtually pest-free.
- 'Tifblue' is the standard. Early: 'Climax,' 'Woodard;' Mid: 'Briteblue,' 'Southland;' Late: 'Delite.'
- Southern Highbush: A cross between Highbush and Rabbiteye. As with Highbush, these will self-pollinate, but yield and size are greatly improved with cross-pollination.
- Early: 'Oneal,' 'Southblue;' Mid: 'Jubilee,' 'Sunshine Blue.'
- Dwarf Varieties for Containers:
- Mid: 'Dwarf Northblue' (20-24 inches); Late: 'Dwarf Tophat' (18 - 20 inches, No pollinator required); the Bushel and Berry series, including 'Jelly Bean' and 'Pink Icing.'
Caring for Your Plants
Pruning: As with all berries and fruits, blueberries will continue producing their best if they are maintenance pruned.
In the first two years, all you need to do is remove any flowers that appear. That’s hard to do, but it will pay big dividends in the long run. Your plants will get bigger and more vigorous because of this. Berries are produced on branches in their second year of growth, so it’s important to be constantly renewing the blueberry bush.
You can leave the flowers on for the third year. You won’t get many berries, but no pruning is necessary until the fourth year.
Beginning in the 4th year, you’ll prune your blueberry bushes in early spring, while they are still dormant. Prune out any:
- Dead or injured branches
- Crossing branches
- Weak, spindly branches
What you want to accomplish by pruning is to open up the bush so that light can reach the berries in the middle of the bush. You don’t need to be too drastic.
Maintenance pruning in subsequent years will amount to thinning out the older branches to encourage new growth. Cut back the oldest, thickest branches to near ground level and prune back branches that have gotten too long or that are growing too thin. Older branches will look gray. Newer branches will have more of a reddish tinge.
Berries form on the fruiting spurs of side branches. The flower buds will be larger, plumper, and rounder than the pointed leaf buds.
Common Diseases and Pest Control
Birds: By far the biggest problem growing blueberries is keeping away birds. With only a few bushes, you can use bird netting as the berries start to ripen. Some gardeners encase their whole blueberry growing area in a netted cage. If you have a large blueberry garden, you should consider using a bird deterrent that sends out a bird in distress call. It keeps birds out of the area.
Insects: Insects to be on the lookout for include: blueberry tip borer, cherry fruitworm, cranberry fruit worm, and plum curculio. If these are common pests in your area, check with your local extension for the prescribed deterrents and treatments.
Diseases: There are some fungal diseases that can affect blueberries, including powdery mildew and leaf spot diseases. Your best defense is to plant resistant varieties. It also helps to give your plants plenty of space for good air circulation, plant in full sun, clean up any fallen debris and replace the mulch annually, so the spores cannot over-winter in the area. If you should experience problems, you may need to use a fungicide labeled for use on edible plants.
Some other common blueberry diseases to keep an eye out for:
- Anthracnose: A fungal disease that spreads rapidly in damp weather. Symptoms are bright pink clusters of spores on the developing berries.
- Botrytis: Another fungus that thrives in damp conditions, botrytis will cause the fruit to shrivel and rot.
- Canker: Fusicoccom (Godronia): This disease begins in the lower parts of the canes. You’ll notice small reddish spots that will enlarge into a bullseye. If left untreated, they will eventually circle and girdle the cane, causing it to die-back.
- Mummy berry: This is one of the more serious diseases to affect blueberries. Mummy berry is caused by a fungus. The first signs of infestation are the blackening of the flower clusters, which eventually die. Because it is a fungus, the spores can linger and infect the remaining blossoms. The resulting fruit turns tan and hard, looking like mummified berries.
- Twig blights (Phomopsis): Twig blight can start off looking very similar to canker. As twig blight progresses, it can also affect the crown, smaller branches, and twigs as well as causing leaf spotting.
Chlorosis (yellowing leaves): It’s not uncommon for blueberry leaves to begin to yellow or look chlorotic. Although this is usually a sign of iron deficiency, it is probably not caused by a lack of iron in the soil. More likely, it is telling you that the soil pH is too high and the blueberry plants cannot access the iron that is already there. If you see yellowing progressing, have your soil pH tested and make adjustments.