Posted in Behind the Scenes, Bookworming, Conservation, Plants

Wild Wednesdays: Northern highbush blueberry

Welcome to the first installment of Wild Wednesdays! This week I’ll be sharing info I’ve learned about the Northern highbush blueberry Vaccinium corymbosum.  It’s the first berry plant we bought for our garden back in 2017.

When we bought that first blueberry bush, we were still really clueless about gardening in general. I found a shrub coupon for our local Agway in a weekly flier, and this plant you see below was one of the the ones we bought that day.  My partner had the idea that eventually we’d work our way up to three of them, and decided to call this one Shoobie, with the idea that the next would be Doobie, and the last Doo.  I liked the idea, so I agreed.  (Yes, we are dorks.)  The pot and the label said it was a native, and back then I believed whatever information was on labels.

A northern highbush blueberry still in the pot it was sold in.
Hello there first food crop plant we bought.

My partner and I like eating blueberries.  We had both been scouts when we were children, and had picked them on camping trips.  For the first year, this was the only plant he cared about in the garden in a purely positive way.  I had looked up basic growing information before the purchase because I knew it was high on our list to add to our garden, and we ultimately chose a spot near to where you see the shot to the left.  That’s the back of our garage, and Shoobie was relatively close so the runoff water from the roof would help keep the initial site moist.  (Yes, I said initial site. I’ll talk about that traveling tale another time.)

I don’t remember when exactly I read about potassium being good for them, and I buried a banana peel right into the root areas maybe a month after planting.  I think I did scoop up some needles from our neighbor’s bordering evergreens while planting because they also thrive in acidic soil (pH of 4.5 – 5.5, higher end is helped with more organic mixed in soil), and the needles will leach out over time.  Where Shoobie is now, as seen in the recent photo I took below, I just threw caution to the wind and heaped needle mulch with abandon.  I did that because one site I looked at while researching for this said, “Don’t bother planting this (blueberry) in anything other than acidic soil.”  Some sites also suggest to mulch blueberries with needles–some say chop them up, others don’t.  I haven’t chopped mine but also haven’t soil tested yet so I don’t really know first hand whether chopping truly hastens the acidification process or not.  I did finally look up where we can send soil to be tested this year, and it’s something we’re planning on doing soonish.  One thing worth noting is they are shallow rooters, which are fine.  Although they are often seen at wetland edges, it’s been noted they favor hillocks that allow them to enjoy consistent moisture without constant wet roots.  Ideal blueberry soil is a well-drained, yet moist sandy loam soil with a pH of 4.5 to 5.2. (This sentence is linked to some other locations in New England that offer tests.)

You can also grow them in containers, just be mindful the drainage in the pot is good so they don’t get miserable from their roots sitting in water.  Some find containers easier if they don’t have an idea acidic soil spot, as its easier to remediate the one or so containers.

Highbush blueberry is a crown-forming shrub that presents upright and grows 6-12 feet tall. Twigs are yellow-green (reddish in winter) and covered with small wart-like dots. Leaves are deciduous, alternate, simple, elliptic or ovate, 1 to 3½ inches long and slightly waxy above with hairs at least on the veins beneath. The white or pink-tinged flowers are small and urn-shaped with 5 petals, and occur 8 to 10 per cluster. Flowering occurs February to June, sporadically in the southern portion of its range; fruiting occurs early July to mid August, about 62 days after flowering. Fruits are ¼ – ½” blue-black berries with many seeds.

One thing I did definitely learn (yet again) is that hands down, bumble bees are the single best pollinator in town with blueberries, because they rapidly vibrate their wings to help shake the pollen loose.  This is something only somewhat recently discovered, and may mean a change is coming for the traveling beekeepers that get paid to go around with their honey bee hives to pollinate multiple farms, because tests have shown that bumble bees are far superior to honey bees for this task.

Proper pruning maintains the productivity of plantings. Young bushes do not need pruning the first 2-3 years, but after that, bushes should be pruned annually when dormant, prior to budbreak in the spring. Damaged or old canes that are no longer producing strong new wood should be removed at ground level. The goals of pruning are to establish a balance of canes (or main stems) of different ages, to remove non-productive wood, and to allow good airflow to minimize pest and disease problems.

A northern highbush blueberry bared in late spring.
As bad as the image is, I like the three shadows behind Shoobie. (Also doesn’t help we planted these three too close together and they’re still young lowbushes–one is mostly cropped out to the lower left.)

In order for blueberry production to be successful, they need to be grown in areas that can satisfy the plants’ chilling requirement, known as chilling hours (an hour below 45º F during winter). This chilling requirement reduces winter injury by keeping the plants dormant. Both blueberry twigs and individual flower buds can be killed or damaged by low temperatures. The temperatures that are critical depend on the degree of dormancy the plants have attained at the time the cold occurs, and to some extent on the variety.  An early hard freeze, before the plants are fully dormant, may cause more damage than much colder temperatures that occur after the plant is fully hardened.

Blueberries can be planted in spring or also in late fall in all but coldest regions. In Zones 5 and below, it’s best to wait until early to mid-spring to plant. 1- to 3-year-old plants are a good choice, and they tend to mature enough to start producing berries between 2-3 years old.  Some sources recommend pinching off flowers years 1 and 2 to direct the plant to focus on branching more than fruiting.

One hazard to planting blueberry is humans aren’t the only fauna on the planet that like them.  One site said that bears are actually the second largest consumer of blueberries, but I didn’t see the fact repeated elsewhere when I was trying to come up with a list of critters that eat them.  (I’ve struggled find a good list.  Many sites have a few listed, some only focus on bird species, and a lot go into how to keep deer away from them because they’ll also eat the woody/bud parts that your blueberry needs to survive another year. Until I find a better list, here’s some mammals + general “birds” list for now and I’ll add to it when I find a better list: black bears, coyotes, raccoons, foxes, porcupines, white-tailed deer and birds.  The foliage is browsed by deer and rabbits.)

Related to whom eats them, Shoobie did get stripped bare of berries in 2019, but we have no idea what happened, as it happened overnight.  We are pretty sure it wasn’t deer or any other animal, really, because they don’t tend to drop imperfect berries on the ground and leave them there.  (We think it was a new neighbor’s kids.)  There also were no tracks, and no foliage was removed on the blueberry bush or any other plants nearby.  It might have been the Acorn Bombers, but they likely would have damaged the young branches, even though Shoobie was still short enough they could have reached most berries without having to try to climb.

Although Shoobie was actually labeled a highbush blueberry, it wasn’t until later that I learned what that really meant (I guessed altitude back then–but it was really simpler than that–it’s a descriptor.  Their height ranges 6-12′.)  But down the research rabbit hole I’d tumble over the years, and there was much to learn.  (And with so many cultivars, that’s even more to remember what’s the same or different!)

Many wild species of Vaccinium are thought to have been cultivated by Indigenous peoples of Americans for thousands of years, with intentional crop burning. V. corymbosum, one of the species likely used by these peoples, was later studied and domesticated in 1908 by Frederick Vernon Coville. He was helped along in his research by Elizabeth Coleman White, a daughter of cranberry farmers, who knew that wild blueberries grew between her family’s cranberry bogs. When she noticed they began to ripen in July, they figured they might complement the cranberry harvest in September and produce additional income.  She had no background in cultivation, so she found someone that was already trying but needed funds, one Dr. Frederick Colville.  She then persuaded her family to underwrite his research.  In 1916, they had their first cultivated commercial crop in New Jersey.

Speaking of cultivating, if you see one labeled “southern highbush”, it’s a cross between V. corymbosum and V. darrowii (a southeastern native), which were created for warmer southern and western regions.

If you’ve ever been tempted to plant the invasive burning bush Euonymus alatus, you can instead grow highbush blueberries in full sun.  Their foliage will shift red and rival the spectacle most seek out with a burning bush.  You can see a bit of that developing in the image at the top.  That’s not leaf burn (which is what I feared at the time), it’s the plant’s natural response to more sun and doesn’t harm the plant from what I’ve read. The picture was when Shoobie was in a part sun/part shade spot.  Some folks even deliberately do full sun hedges of them, and there are several cultivars that are bred specifically to bring out the reds.

3 Things you might not know about blueberries:

  1. Blueberries are one of the fruits used by Indigenous peoples of America to make pemmican, often made in preparation for winter months or long hunts. Depending on the region, blueberries are often one of the fruits specifically reserved only in the making of ceremonial pemmican.
  2. Creating pollinator friendly habitat with flowers that bloom here in New England from April-June near or in the same bed as northern highbush blueberries will help attract beneficial insects. Once they know your garden is a reliable food source, they’ll have set it as a good place to return by the time your blueberries are needing their help.  It’s best if you can offer pollinator plants that bloom throughout the growing season, but making sure you attract them early will give you a better chance to expect them when your blueberries are in bloom.
  3. The blue color of the fruit reflects the presence of anthocyanins, which are antioxidants with anti-inflammatory, anti-viral, and anti-cancer properties.

Next week Wild Wednesdays will feature paper birch, which we also happen to have on our property and is a host plant to one moth I love to see here.

the Farmer’s Almanac
Medium article, “A Fruitful Partnership
MCBGA (Massachusetts Cultivated Blueberry Growers Association)
Native Plants for New England Gardens, Mark Richardson and Dan Jaffe
Native Plant Trust: Go Botany
the Old Farmer’s Almanac
University of Massachusetts (UMass) Extension Fruit Program
USDA NRCS (United States Department of Agriculture, National Resources Conservation Service)
U.S. Highbush Blueberry Council

If you have any additional information about northern highbush blueberries you’d like to share or thoughts related to this entry or about the Wild Wednesdays series in general, feel free to leave a comment below. If there are any native plants from New England you would like to know more about, please let me know in the comments below, and I’ll try to cover them in a future installment of Wild Wednesdays.

Care to share thoughts on this?