growing blueberries

Fruit for the Month: February

Young blueberry plant in snow. Photo Bridget Aleshire

We are in the dormant period for most fruits, with really none to harvest, although this is a good month to eat stored and preserved fruit.

Depending on your climate, you could start to plant new fruit bushes and canes, and whether you do that or not, there is plenty to prune and care for.

Blueberries are the Focus Fruit for February

Harvest blueberries in June in the mid-Atlantic. Photo Small Farm Central

Blueberries were also the Focus Fruit for June, when I wrote about harvesting them, and about the differences between Rabbiteyes, Northern Highbush and Southern Highbush types, and about planting. If you are about to buy plants, let me remind you that we have bought good plants from Finch Blueberry Nursery in Bailey, North Carolina, as well as from a more local source in SW Virginia (now retired). If you only want a few plants, buy potted blueberry plants locally. Otherwise, order bareroot plants shipped to you. In Virginia Edible Landscaping offers a wide choice.

Blueberry bush with buds in March. Photo Pam Dawling

It used to be a tradition here, that the first garden shift of the year, in late January or early February, after the winter break, was spent pruning blueberries. During December and January, only a few people were working in the gardens, harvesting hardy crops, and tending to the hoophouse and greenhouse. Once the rest of the crew returned, we cleaned, sharpened and oiled the pruners, and set to work.

We have two patches of blueberries, both Highbush, despite being in a climate where you might expect Rabbiteyes to do better. The older patch has four rows of eleven bushes, which have been growing there since before 2007. Mostly we don’t know the names of these varieties. We have replanted to fill gaps over the years, and each spring we have logged how they are doing, whether they are early or late, productive or not, small or large berries, delicious or OK.

Young blueberry plant protected for winter with mesh.
Photo Kathryn Simmons

The newer patch was planted in November 2007, with 4 plants each of five varieties, planted in two rows in the order we expected them to ripen: first Duke, then Spartan, Bluecrop, Chandler and Aurora. The Duke variety has by far been the best, both productive and tasty. The Spartan early on declared itself to not be suited to our location. We have digital records of this patch from 2016-2019. Probably we have paper records from 2007-2015. At the last count, we had 4 Duke, 1 Spartan, 6 Bluecrop, 3 Chandler and 6 Aurora. We have propagated Duke to replace casualties in the old patch.

If you are looking for good varieties for central Virginia, here’s what I gleaned from our notes:

Duke: Good strong, productive plants
Spartan: Not right for this area, didn’t thrive
Bluecrop: Did well initially, started to die out by 2016
Chandler: maybe earlier than Bluecrop, large berries.
Aurora: Very late, large berries, so-so flavor.

Blueberry Plan/Annual Calendar

Late January/February in a mild spell: Pruning (See Special Topic below)

Late January/early February:

Weed
Add soil amendments such as sulfur, if soil test indicates a need.
Add compost
Renew mulch: Rake remains of old mulch aside first. Double cardboard, then replace old woodchips and top up to 3” with new woodchips or sawdust. The new patch had landscape fabric underneath at first, but that was removed, so it now needs double cardboard and new chips, just like the old patch.
Plant new bushes to replace casualties.
Repair fencing if needed.

Early Spring (April? March if there’s a drought):

Check irrigation and start irrigating twice a week. Weed.

Late Spring (May):

Old patch – tackle Nut Sedge by several repeated cultivations with rakes or hoes when nut sedge is 3-4” tall.
When flowers are setting fruit, install the roof netting.

Blueberry netting on hoops.
Photo Bridget Aleshire

June:

Harvest.

Summer (August):

Weed. After harvest, remove and store the roof netting, check perimeter fencing.

Fall (September/October/November):

Prepare new area if needed. Plant new bushes in November (or wait till Feb)

Weed, spread compost, mulch, take soil tests.

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Pruning young blueberries.
Photo Lori Katz

Special Topic for February: Prune Blueberries

Late January/February in a mild spell:

1-2 year old bushes: remove all flower buds (the plump round ones). Remove tiny weak shoots and leave a sturdy bush.

General, all ages: Remove all dead, diseased, damaged and dying wood.

Decide whether to propagate. To layer a low-lying branch, scrape the bark on the underside, pin it down to the ground with a 6” wire staple, weight the pin down, and flag it. Layering has been much more successful for us, but it is possible to make hardwood cuttings, with 3-5 buds hardwood sticks (not flowering tips), and root these.
Remove cross-overs, low-lying branches, branches heading for the center of the bush, branches hitting the roof of the netting.
For young bushes, up to 4-years old, that’s all the pruning you do. Aim to leave a sturdy, healthy bush. Focus on removing spindly stuff. For older bushes, continue with step 5 onwards.
Count the thick old trunks bigger than 1.5” diameter, divide by 5 and saw out this many, at ground level, (unless it would leave fewer than 6). Choose the oldest, scaliest, darkest ones for removal.
Remove any spindly growth, tangled clusters.
Remove a portion of the younger stems, to leave a balance. The ideal is something like 20% less than 1” diameter, 60% 1-2”, 20% larger than 2” diameter.
Bear in mind that the fruit buds are plump – don’t remove more than 50% in total, but don’t fret about removing up to this number. If the bush carries too much fruit, berries will be small, branches break and bush reserves get depleted.

Layering a blueberry branch to propagate a new bush.
Photo Kathryn Simmons

Here’s information from Pruning Blueberries in Small Fruit in the Home Garden from Virginia Extension

“Until the end of the third growing season, pruning consists mainly of the removal of low spreading canes, and dead and broken branches. As the bushes come into bearing, regular annual pruning will be necessary. This may be done any time from leaf fall until before growth begins in the spring. A mature blueberry plant should produce three to five new canes per year.

During pruning, clean out old, dead wood, and keep the three best 1-year-old canes. Locate the oldest canes and prune out one of every six existing canes; cut as close to the ground as possible. A mature blueberry bush should have 10 to 15 canes: two to three canes each of 1-, 2-, 3-, 4-, and 5-year-old canes (fig. 3).”

Figure 3

Figure 3. Left, unpruned blueberry plant. Right, after
pruning, a mature blueberry bush should have 10 to 15
canes.

Blueberry flowers.
Photo Kathryn Simmons

More Blueberry Resources:

Blueberry Production Guide (NRAES-55) 1992, Pritts and Hancock
NRAES-055_ePub.epub (10.54Mb)
Cornell 2022 Organic Production and IPM Guide for Blueberries, Carroll and Pritts
Strik, B.C., D. Bryla, and D.M. Sullivan. 2010. Organic Blueberry Production Research Project. eOrganic article.

Other small fruits still available in February

Dried and frozen fruits, jams, jellies, chutneys, other preserves, or even stored apples and pears come into their own this month. Pawpaws can be eaten frozen like ice cream. Don’t eat the skins, and don’t eat cooked pawpaws, or you may get Tummy Trouble.

Wintergreen berries persist on the plants in the wild all winter, but don’t taste good at the end of the winter, though, so do a taste-test before harvesting lots. If you are allergic to aspirin, avoid wintergreen because all parts of the plant contain methyl salicylate, an aspirin-like compound.

Other fruit care in February in the mid-Atlantic

Summer-fruiting raspberries: cut out old canes (last year’s fruiting canes), Thin new canes (that didn’t bear fruit last year) to 6 per foot of row (ie at least 2” apart). Weed. Water.

Fall raspberries: Prepare future new beds. Plant new canes with compost. Mulch around them. Set new T-posts for trellising once the new canes start growing. In existing beds, cut all last year’s canes to the ground and dig up canes from aisles. Weed, compost, mulch.

Don’t let this happen to you: A frosted strawberry flower with a black center.
Photo Kathryn Simmons

Strawberries: Remove any winter hoops, polypropylene rowcover or slitted plastic and clips. Plant a new replacement bed if not done in August or September. Restore paths if needed. Weed. Compost if none in August. You could keep the rowcover handy for the flowering period, to cover in frosty weather. Or you could pack it away while you tidy up the beds and paths, and get it out again once you see flowers.

Rhubarb: Weed, compost around the plants, or where you think the plants are! Mulch if not already done in the fall

Grapes: Weed. Spread compost. Install irrigation. Prune: 50 buds per vine. Prepare sites for new vines.

Fruit for the Month: June

This is another post in my new monthly series, about small fruits that can be grown sustainably in a mid-Atlantic climate. I’ll talk about planting, pruning, harvesting and care of the plants, according to the season. I’ll give links to useful publications. I’ll have a focus fruit, and then more about others that need attention during the month. We do grow apples and pears, and some other tree fruit, but I’m not writing about those as I don’t have much recent experience.

Blueberries are the focus fruit for June

June is the month in our climate, to harvest blueberries. Blueberries are a great crop to grow, as they are not troubled by many pests or diseases (apart from birds). While you are harvesting take notes (or photos) of the various varieties you have, and when and how well they are producing, so that you will know which ones to propagate from in the winter, if you want more.

See my article about blueberries in Growing for Market magazine

See ATTRA Blueberries: Organic Production available free online, for a wealth of information from choosing varieties, planting, details on pests and diseases you might encounter. Updated 2022. Also search the ATTRA site for other info on blueberries, such as soil management (blueberries need acid soil), living clover mulches, and honeybees and alternative pollinators.

Harvesting blueberries

Blueberry harvest. Note “berry bucket” hanging around the worker’s neck. Photo Marilyn Rayne Squier

I recommend harvesting two days a week, in the mornings, once the dew has dried, to avoid spreading fungal diseases. Blueberries don’t deteriorate or over-ripen as quickly as softer fruit, so if you can only find time once a week, that will be OK. Or if you are selling blueberries, once a week may work better for your sales. Blueberries don’t crush as easily as strawberries or raspberries, so if you have lots you can put them in buckets or crates. We usually harvest into homemade berry buckets with long rope handles, that we can hang around our necks, freeing up both hands for picking berries. Our berry buckets are made by cutting plastic gallon jugs and adding rope through holes we punch near the top. Full berry buckets get emptied into a bigger bucket.

Only pick the berries that are purple-black all over. Check the back of each each ripe-looking blueberry to make sure it’s ripe all over. The area around the stem is the last to change color. Really ripe blueberries will “tickle” from the bush into your hand

Do not wash fruit before refrigerating, as this leads to rot.

Types of blueberries

We grow Northern Highbush blueberries here in winter-hardiness zone 7a (suitable for zones 3-7) and we like to have a crop we can harvest standing up! There are also lowbush blueberries, which are popular in cooler climates, such as Maine. Rabbiteye varieties are better to the South, in the region roughly south of Interstate 40 (mostly zones 6-9). Rabbiteyes are taller plants, with smaller berries than highbush types. A new hybrid type, Southern highbush, is adapted to the southern rabbiteye zone and the coastal South (zones 6-10). Look into these if you are in the right area: they have a lower chilling-hours requirement, and flower and fruit earlier than highbush or rabbiteye varieties. As the climate changes, fruit growers are challenged by traditional crops no longer getting enough winter chilling hours to fruit. (Chilling is the number of accumulated hours at temperatures below 45°F/7°C in the dormant season.) Balance this with your changing frost dates, as earlier flowering will not be an advantage if your last frost is going to cancel the fruit. Remember that all blueberries are self-fertile but will produce better crops if you plant several compatible cross-pollinating varieties.

Young Blue Crop northern highbush blueberry.
Photo Kathryn Simmons

At our farm, Duke has been a very reliable early fruiting highbush variety, whereas Spartan has not worked out. We like to have several varieties with different ripening dates, to extend the harvest. Blue Crop, Blue Jay, Elliott and Chandler also do well here. If I was starting over, I’d also try some Southern Highbush varieties.

We have bought good plants from Finch Blueberry Nursery in Bailey, North Carolina, as well as from a more local source in SW Virginia (now retired). If you only want a few plants, buy potted blueberry plants locally. Otherwise, order bareroot plants shipped to you. In Virginia Edible Landscaping offers a wide choice.

When to plant blueberries

If you are planning to plant blueberries, here are some considerations. Generally you will want o buy young bushes and plant them in the dormant season. In warm areas, plant in late fall so the plants get roots established before your early spring thrusts them into opening buds. In cooler zones, plant in early spring, so that winter does not kill them.

New blueberry plant with winter wire mesh protection. Photo Kathryn Simmons

As with all perennials, clear the area of perennial weeds the previous year, and reduce annual weeds, for instance by growing a good cover crop, which will smother emerging annual weeds and also feed the soil. Get a soil test, and follow the recommendations to amend the pH to 4.8-5.5 using sulfur in spring or fall before planting. I like the pelleted sulfur, that looks like lentils, because it is easy to spread, and no dust gets in your lungs. Depending on your soil type, you might need 430-1750 pounds of S per acre, or 1-4 pounds per 100 sq ft. Work in some good compost before planting.

Plan space between the rows that will let you walk, mow or whatever you need to do even once the bushes have reached full size. 8-12ft is recommended. Ours are a bit closer than that. In the row you can either plan for a hedge effect, or leave yourself access space. You can plant blueberries on raised beds or wide ridges. You can move bushes later in life, if you find they are competing too much.

Blueberries six years after planting. Photo Kathryn Simmons

Plan how you will cover the soil. I recommend landscape fabric topped by bark mulch or woodchips. This combination works well to keep perennial weeds at bay (wiregrass!). If you are avoiding plastic, you can use double layers of overlapping cardboard topped by 3” of organic mulch: chips, sawdust, straw or spoiled hay. Blueberries don’t do well with plastic mulch that is impervious to water, as it encourages the roots to grow just under the plastic, where they can easily get overheated and die. Some people like to grow a living mulch, perhaps mowing it to mulch closer around the plants once it dries. A hybrid model has mulch in the rows and a cover crop between the rows.

Blueberries have shallow roots, so you will likely need some irrigation method. I like drip irrigation, but overhead sprinklers work too.

You will, of course, have some annual care to provide. Each spring, expect to provide some source of nitrogen and potassium, as needed. I’ll cover that another time. Each winter, prune for strong branches and good levels of production, and remove any perennial weeds.

Blueberries showing Tenax fencing and basket balls on posts to support roof netting. Photo Kathryn Simmons

Pests to watch out for include big ones like deer, groundhogs, birds and uninvited humans. We have a triple fence, with wire netting in the ground against burrowing animals, 7’ tall Tenax deer fencing, and seasonally, Avigard flexible bird netting over the top. For our newer blueberry planting we make a temporary hooped structure and cover just with the bird netting, held down to the ground with 6” soil staples. This planting is nearer our buildings than the older one, and is not visited by deer or groundhogs.

Blueberry netting on PVC electrical conduit hoops. Photo Pam Dawling

Smaller pests include blueberry maggots, blueberry stem borers, cranberry fruitworms, cherry fruitworms, Japanese beetles, leafrollers, leafhoppers, and aphids. Our perhaps, like us, you will not be troubled by any of these.

Diseases include mummy berry, Botrytis grey mold, Anthracnose, stem blight, stem canker, rust, phytopthora root rot, Phomopsis twig blight, blueberry stunt and several viruses. A Cornell University blueberry diagnostic tool offers a step-by-step exercise to help figure out what diseases may be affecting your crop.

Propagate blueberries by layering a low branch, as you see here with Chandler variety. Photo Kathryn Simmons

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Other small fruits available in June

Two rows of floricane raspberries with a willow and grapes in the background. Photo Kathryn Simmons

Cherries, red raspberries, strawberries, Juneberries, gooseberries mulberries. Blackberries, apricots, peaches, plums.

If you live in Virginia or nearby, see this produce calendar

Other fruit care in June

New grape vine in May. Photo Bridget Aleshire

Grapes: Mow, weed, water in drought. If you have young vines, remove side branches from the trunks, and fruitlets. Your goal is to first grow strong plants, then produce grapes after that.

Strawberries: Prepare for new strawberries in early June: Disk or till the area for new strawberries if using bare-root plants, and prepare the beds with compost, driptape, and landscape fabric.

June 16-July 16: If using bare-root transplants, plant new strawberry beds.

Late June/early July (after fruiting): Dismantle two-year-old beds. Renovate carry-over strawberries by mowing or shearing/clipping weed and mulch, but don’t compost them. . Plant new strawberries if using bare-root transplants, perhaps rooted runners in the paths of older beds.

Rainbow and Kathryn spread hay over the new strawberry bed. Photo Luke Stovall

All fruit: Water all fruit crops. Weed, mow aisles as needed. Weed and mulch rhubarb, lop flowers. Record condition and fruiting dates of new grapes, blueberries. Note best varieties.