Blueberries

Estimated reading time: 8 min

Before my momma’s blueberry bushes started churning out gallons of blueberries, we visited the neighbor’s UPick. They knew us, luckily. If they hadn’t, they’d have taken one look at mine and my sister’s purple-stained lips and called the cops. Back then, we always ate more than we picked. The no eating at the UPick rule flew right over our heads. I think my momma always paid a little more than they said we owed.

Blueberries, which are native to North America, grow throughout the continental US. Since the 1930s, European, Asian, and South American growers have all discovered the joys the of this culinary delight. Their wide native range means that there likely is a blueberry suitable for your climate and growing conditions.

Evergreen, or box, blueberries grow along the west coast, mountain blueberries in the Cascade Mountains, dryland blueberries throughout the southern half the Appalachian Mountains and Arkansas, highbush up the east coast and along the parts of the Great Lakes, lowbush in the northeast, and rabbiteye blueberries in the deep south. Northern and southern highbush remain the most popular commercial types.

Pre-Planting

Blueberries set fruit in their second or third year but don’t reach full production until their fourth or fifth year. Eight years after planting, your blueberries are considered fully mature, and they’ll continue producing for 20 years or more. Like most fruits and nuts, blueberries are a long-term crop. During the first four years, market farmers should expect minimal, if any, revenue from their blueberry crop and focus on short-term crops, e.g., potatoes, green beans, onions, lettuce, and tomatoes, for their livelihood.

Selecting Varieties

For large plantings, using a single, self-fertile variety is easier to manage. However, cross-pollinated blueberries generally larger fruit, produce more seeds, and ripen earlier. Even if you select self-fertile blueberries, choose 2-3 cultivars that bloom at the same time for the best results.

If you anticipate a spring freeze during bloom, look for varieties that are spring freeze resistant. Always check your chill hours and the berry’s harvest time. To learn more about chill hours and how to figure out how many you get, see “Know Your Chill Hours, the Fruit Grower’s First Rule”.

Whenever possible, choose a blueberry native to your area. These are often hardier and achieve better results. For example, I grow Powderblue and Tifblue blueberries. These produce better in my area than southern highbush blueberries. (Tifblue was developed less than an hour away.) If you go two hours east, southern highbush blueberries are more reliable.

Blueberries are very regional. Always check with your county’s extension office. They’ll know what varieties work for your area and whether you should plant a different variety when you move from the western side of the county to the eastern.

Location and Site Preparation

Although blueberries appreciate full sun, they have shallow roots. Due to their height, high bush and rabbiteye blueberries are susceptible to blowing over during summer and autumn storms. When possible, choose a sheltered area with full sun.

Ideally, select a site with a soil pH of 6.2 or lower. Keep in mind that while mulches and sulfur can help lower pH, these fixes will require repeated applications throughout the life of your blueberries.

Before your next heavy rain, dig a hole 6 to 8 inches deep. Check the water level 24 hours after the rain stops. If there’s still water, either select a site with better drainage or plant your blueberries on a ridge so 6 to 8 inches above the water level.

About 3-4 months before planting, apply wettable sulfur to adjust the soil pH to between 5.0 and 5.5. 1 lb (2.5 cups) should lower the pH of 100 square feet of sandy soil by 1. Use 2 lbs (5 cups) per 100 square feet for clay soil.

Planning Your Blueberry Planting

Before planting, decide whether you require one variety, two varieties, or three. Using the spacing recommended for your specific varieties, which may differ from the generic spacing’s below, layout your plants and irrigation system on graph paper before your order!

Bees, Beekeeping & Pollination Figures 5 through 7 illustrate the best pollination layouts for blueberries.

Before planting, decide if drip irrigation or micro-sprinklers best suit your planting and water situation. Small patches with fewer than ten plants may need access to a water spigot instead of a full irrigation system. If planned correctly, these can be watered with a single overhead sprinkler.

See “Laterals: applying irrigation water” in Low-Volume Irrigation Systems for Blueberry with Chemigation and Fertigation Suggestions for information on designing an irrigation system for your blueberries.

If you need frost protection, review Commercial Freeze Protection for Fruits and Vegetables. Keep in mind that these practices are not always practical or cost effective for small plantings. I’ve used overnight sprinklers, frost blankets, and even Christmas lights (not LED lights) to protect my blueberries.

Fertilizing and Soil Amendments

Do not add fertilizer before planting your blueberries. This may burn the roots.

Apply 4-6 inches of organic material, preferably peat moss or decayed pine sawdust or bark, to rows and till it to a depth of 6 to 8 inches.

Planting

Select potted or bare root blueberry plants that are 2 to 3 years old. Keep the roots moist before and during planting.

Dig a hole at least 18” across and 1-2” deeper than the pot. For bare-root plants, dig until you’re about 6” below the plant’s original soil line. After transplanting, firm the soil and water thoroughly.

After planting, prune the top 2/3 of the bare root plants and the top ½ of the potted plants, leaving 1-3 of the strongest shoots. Remove any flower buds.

Apply 4’ of decayed pine bark, decayed pine sawdust, or another acidic mulch. Do not use chipped construction waste, aged horse bedding, or hardwood mulches as these materials may raise the pH.

If you already have an established blueberry patch or you want blueberries exactly like your neighbor’s, blueberries may be propagated from both seeds and cuttings. See Growing Blueberries from Seed and Propagating Highbush Blueberries for more details.

Blueberry Spacing

Row: 10’-12’

Plants: 3’-5’

Note, the above are average spacings. Always check the spacing for your chosen varieties. Larger shrubs may require more space.

Care

Always monitor your plant’s growth. Mature blueberries don’t need to grow more than 1’ per year. If they exceed this, cut back on the nitrogen.

First Year

After the leaves emerge, apply about 1 tablespoon of azalea fertilizer or 10-10-10 around the base of each plant 1 foot away from the trunk. Repeat every 6 weeks until early to mid-August (late summer).

Second Year

After the leaves emerge, apply 2 tablespoons of azalea fertilizer or 10-10-10 about 1 ½ feet from the trunk. Repeat application using the same schedule as the first year.

Bearing Years

Bearing blueberries require about 1 cup of 10-10-10 fertilizer per plant applied about 3 feet from the base as soon as new growth appears. Repeat using the same schedule as the first year.

Weeding

Use mulch to help control weeds and keep your blueberries weeded. Be caution when using mechanical cultivation because blueberry roots are shallow and easily damaged.

Spring Tasks

  • Test soil pH. If it’s higher than 5.5, apply 1/10 lb of wettable sulfur per bush on the outer edge of the bush’s canopy. Each 1/10 lb should reduce the soil pH by 1 unit. Avoid applying sulfur every year.
  • Check the mulch and reapply as needed until it reaches a depth of 4”.

Fall Tasks

  • Add more mulch if needed.

Pruning

Some sources recommend pruning your blueberries in the late winter/early spring when the flowering buds are visible and before the leaves emerge. Others suggest pruning while the plant’s dormant during the winter and still others recommend pruning them as soon as you’ve finished harvesting. I’m a winter pruner.

Regardless of which pruning school you join, pruning your blueberries always removes bearing branches. This will reduce your overall yield. However, it also produces bigger berries. Some highbush and rabbiteye growers prune every other year, alternating fields or rows (1 for each year, but never both at the same time) so they’ll have both a consistent yield and larger berries.

When your mature blueberries begin producing less, it’s time to prune. You won’t see huge benefits the first year, but you will the next.

For highbush and rabbiteye pruning diagrams, see Home Garden Blueberries. Pruning Lowbush Blueberry Fields discusses thermal pruning (fire) and mower pruning.

Birds

Those pretty bluebirds raising their young outside your kitchen window can and will eat their weight in blueberries. Draping mesh bird netting over your blueberries is often the difference between having blueberries and not.

Harvest

Once mature, highbush and rabbiteye blueberries should produce about 10lbs per plant.

If you own more than 6 blueberry bushes and you’re not operating a UPick operation, invest in a blueberry rake. These time-saving devices come in highbush and lowbush variants. Take care to only pick the ripest berries and not the green ones. You’ll need to winnow out the leaves and then pick out any twigs or unripe blueberries. Even with the extra processing, you’ll still save hours.

If you harvest wet blueberries, you run the risk of infecting your entire day’s harvest that makes them spoil quicker. Don’t harvest them wet.

Rinse the blueberries. When floating or rinsing, gently agitate the blueberries being careful not to bruise them. Let them dry.

Pick your blueberries when they turn dark blue. If you’re not sure if they’re ready, pick a few and taste them. Keep freshly harvested berries out of the sun.

Avoid picking blueberries during the heat of the day. Do not use rinse water more than 10 ⁰F cooler than your berries. It can damage their flesh. Never ice your blueberries.

Refrigerate your berries within 4 hours of picking them. Store blueberries at 33 ⁰F to 34 ⁰F, 90% to 95% humidity. They should keep for 2 to 3 weeks.

At the Market

Place a few baskets of blueberries out as both samples and displays. Keep the remainder in a cool place. You can pre-package them in pint-sized baskets. Since the cute baskets cost money, please don’t be afraid to hang up a sign asking your customers to bring their own containers. Transfer the blueberries to their container or a plastic or paper bag and reuse the basket.

At Home

Turn your leftover blueberries into jelly, jam, and pre-canned pie filling. Although freezing blueberries changes their texture, frozen blueberries make amazing muffins, pancakes, pies, and smoothies. For an amazing treat, toss some into a dehydrator. Dried blueberries are possibly the most amazing dried food you will ever taste. Don’t expect them to last though.

References

  1. Small Fruits | NC State Extension Publications. (n.d.). Retrieved October 25, 2018, from https://content.ces.ncsu.edu/extension-gardener-handbook/14-small-fruits

229-Pruning Lowbush Blueberry Fields | Cooperative Extension: Maine Wild Blueberries | University of Maine. (n.d.). Retrieved October 26, 2018, from https://extension.umaine.edu/blueberries/factsheets/production/pruning-lowbush-blueberry-fields/

Blueberry | Diseases and Pests, Description, Uses, Propagation. (n.d.). Retrieved October 21, 2018, from https://plantvillage.psu.edu/topics/blueberry/infos

Cano Medrano, R. (1994). Pollination and GA3 Effects on Fruit Growth, Sucrose Metabolism, Cell Number, and Cell Size of Blueberry Fruits. Retrieved from http://archive.org/details/pollinationga3ef00cano

Commercial Freeze Protection for Fruits and Vegetables | UGA Cooperative Extension. (n.d.). Retrieved October 25, 2018, from http://extension.uga.edu/publications/detail.html?number=B1479&title=Commercial%20Freeze%20Protection%20for%20Fruits%20and%20Vegetables

Ernest, E. (2015, May 8). Mulching Blueberries. Retrieved October 26, 2018, from https://extension.udel.edu/weeklycropupdate/?p=7967

Fertilizing Blueberries in Pine Bark Beds | UGA Cooperative Extension. (n.d.). Retrieved October 25, 2018, from http://extension.uga.edu/publications/detail.html?number=B1291

FS419: Selecting Blueberry Varieties for the Home Garden. (n.d.). Retrieved October 25, 2018, from https://njaes.rutgers.edu/fs419/

Growing Blueberries From Seed | Cooperative Extension: Maine Wild Blueberries | University of Maine. (n.d.). Retrieved October 24, 2018, from https://extension.umaine.edu/blueberries/factsheets/cultivated-lowbush-blueberries/growing-blueberries-from-seed/

Highbush Blueberry Production. (n.d.). Retrieved October 21, 2018, from https://extension.psu.edu/highbush-blueberry-production

Home Garden Blueberries | UGA Cooperative Extension. (n.d.). Retrieved October 26, 2018, from http://extension.uga.edu/publications/detail.html?number=C946&title=Home%20Garden%20Blueberries#Planting

Honey Bee Program – Bees, Beekeeping & Pollination – Crop Pollination Requirements. (n.d.). Retrieved October 25, 2018, from http://bees.caes.uga.edu/bees-beekeeping-pollination/pollination/pollination-crop-pollination-requirements.html

ID-210: Midwest Blueberry Production Guide. (n.d.), 58.

Masabni, J. (n.d.). Blueberry Production. Presented at the UKREC, Princeton, KY. Retrieved from https://www.uky.edu/Ag/Horticulture/masabni/PPT/blueberry.pdf

Post-harvest Handling of Blueberries « Northwest Berry & Grape Information Network. (n.d.). Retrieved October 21, 2018, from http://berrygrape.org/post-harvest-handling-of-blueberries/

Postharvest Cooling and Handling of Blueberries | NC State Extension Publications. (n.d.). Retrieved October 26, 2018, from https://content.ces.ncsu.edu/postharvest-cooling-and-handling-of-blueberries

Schulte, N., & Hancock, J. (n.d.). Propagating Highbush Blueberries, 4.

Scott, D. H., Draper, A. D., & Darrow, G. M. (1978). Commercial Blueberry Growing. Washington : U.S.D.A. Science and Education Administration : Retrieved from http://archive.org/details/CAT79707644

Smith, E., Porter, W., & Oliver, J. (n.d.). Low-Volume Irrigation Systems, 17.

Sources of Rakes and Harvesters | Cooperative Extension: Maine Wild Blueberries | University of Maine. (n.d.). Retrieved October 21, 2018, from https://extension.umaine.edu/blueberries/factsheets/production/sources-of-rakes-and-harvesters/

Southern Highbush Blueberry Marketing and Economics | UGA Cooperative Extension. (n.d.). Retrieved October 25, 2018, from http://extension.uga.edu/publications/detail.html?number=B1413&title=Southern%20Highbush%20Blueberry%20Marketing%20and%20Economics

 

 

Kristle Chester

Kristle Chester

Author

Writer, Researcher - My Homestead Planting Guide. Kristle Chester lives in southern Georgia with Dex, the spastic spaniel, and three chickens, who miraculously survived the day Dex discovered that chickens are birds. Most mornings, you’ll find her digging in the dirt, picking peas, or staring at the watermelons. She’s yet to learn that watched watermelons never grow. (indexwriter.com)


 

 

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