Ask Ruth: Blueberries
I am thinking about planting some blueberries. Are they hard to grow?
Michelle, Burnsville NC
I love this question, because blueberries are one of my favorite plants. We sell lots of blueberries at the garden center where I work, and we like to remind people that blueberries – in addition to the berry production – are a beautiful ornamental plant that will enhance the landscape in your yard.
They are covered with pretty pinky-white bell shaped flowers in spring. In summer they produce yummy berries that are power packed with anti-oxidants. As cooler weather approaches, their leaves turn yellow, orange and red…with truly spectacular fall color. Blueberries are deciduous (they loose their leaves in winter), but even in winter they are an interesting plant – with reddish stems and somewhat exfoliating bark.
Blueberries are a native plant that grows wild in WNC. You can pick them in the summertime at places like Roan Mountain (near Bakersville), Craggy Gardens (MP 364.4), and Graveyard Fields (MP 418). The wild berries are small and very flavorful. Cultivated blueberries have larger berries, they are easy to grow, and they are generally disease and pest free. These amazing berries are a fantastic source of vitamin C and manganese; they are high in dietary fiber and contain almost no fat; they are packed with antioxidants…and they’re just 80 calories per cup.
Cultivated blueberries have larger berries, they are easy to grow, and they are generally disease and pest free.
There are a few self-pollinating blueberries, but in general, you will need to plant two different cultivars of blueberries to get good berry pollination. Highbush blueberries (Vaccinium corymbosum) are most commonly planted in Western North Carolina. ‘Blue Crop’, ‘Jersey’, ‘Blue Ray’ and ‘Patriot’ are old standards, but there are many wonderful cultivars available.
I personally have never tasted a blueberry I didn’t like. They’re all delicious! Lowbush blueberries (Vaccinium augustifolium) are very low-growing and will spread to form a dense groundcover. They can be an unusual addition to your edible yard. Rabbiteye blueberries (Vaccinium ashei) are the third type. Even though Rabbiteyes are only hardy to Zone 7 (we are Zone 6), some people in our area have great success with them. Highbush/lowbush crosses have been also developed – I have one called ‘Northcountry’ that only gets about two feet high. It’s a great choice for urban settings, containers, and small yards.
Blueberries are easy to grow but they do require an acid soil, excellent drainage, and consistent moisture. If you want the plant to thrive, attend to these needs.
Check Soil pH
Before planting, test your soil pH. Blueberries need an acid pH of about 4.5 (adaptable to a range from 3.8 to 5.5), which is considerably lower than what most plants require. If your soil needs acidifying, you can add sulfur or a soil acidifier to lower the pH. I would avoid using aluminum sulfate for food crops.
Plant in full sun for best fruit production (it is OK to plant in part sun, but you will not get as much fruit). Blueberries require good drainage, so don’t plant them in the straight clay found in most yards in the mountains. Dig a generous hole about three times the width of the pot – or about three feet wide and about one foot deep.
Plant the blueberry a little higher than the surrounding soil (never below the surrounding soil level). Your backfill should be 50% native soil mixed with 50% soil conditioner (Nature’s Helper is one brand name) or peat moss. Compost is NOT recommended for amending the soil when planting blueberries. Their roots are extra-sensitive, and hot compost or manure can burn their new root growth. Mix a handful of azomite or kelp into the backfill to add some micro-nutrients.
Like all newly planted shrubs, water your blueberry twice a week to the BOTTOM of the rootball for the entire first year. Blueberries like generous (but not swampy) amounts of water. If your blueberry goes bone dry, it may actually die. Adequate water is a must for plant survival, and even established plants can die if water is insufficient. Pay special attention to water when the fruit is forming.
Mulch your blueberry to prevent weed growth and to retain moisture. Commonly used mulches are pine straw, shredded pine mulch, or sawdust. If you use sawdust, use aged sawdust. Fresh sawdust will rob nutrients from your blueberry. Hold the mulch back a little from the canes of the blueberry.
Don’t fertilize when you initially plant your blueberry. Fertilize every year when the flower buds begin to open, and again about one month later. Use a fertilizer for acid-loving plants, like Holly-Tone. An excess of nitrogen will produce lots of leaf growth, but will diminish fruit production. Barely scratch the fertilizer into the soil, because blueberries are very shallow-rooted and you don’t want to damage the roots.
Prune blueberries annually in early spring/late winter. When canes get larger than one inch in diameter (this could take around eight years), prune them out at the ground. Remove any crossing branches or dead branches every year. Canes that are ½ to 1 inch in diameter are the most productive, and about 16 canes are ideal. Most highbush blueberries grow to about 4-6 feet tall and 4 feet wide.
The first year you should remove all the berries a.s.a.p. so that the plant will not spend its energy making fruit – you want that energy spent on producing roots.
Blueberries aren’t really ripe until about a week after they have turned blue. Fully ripe berries will have a whitish “bloom” or fine dusty appearance and will show no red at the stem end. Ripe berries should fall off the bush easily, so harvest only the ripe berries and check back in a day or so to see if the other berries have ripened.
Once harvested, you can pop your berries right into your mouth, make a pie or preserves, or freeze the berries. To freeze the berries, spread them out on a cookie sheet and put them in the freezer. Once frozen, immediately transfer them to a freezer bag or box (this way they won’t stick together and you can use just the quantity that you need as you need it).
Birds love blueberries too, so you may need to cover your plants to keep the birds from eating them up. You can purchase bird netting, or use something like cheesecloth or floating row cover to keep the birds from feasting on your blueberries. Harvesting your berries regularly, at least twice a week, will help reduce bird damage too.
Michelle, I think you are going to have a tasty adventure with this easy-to-grow fruit.
Ruth Gonzalez is a former market farmer, gardener, local food advocate, and founder of the Tailgate Market Fan Club where she blogs at http://tailgatemarketfanclub.wordpress.com. In her job at Reems Creek Nursery, Ruth offers advice on all sorts of gardening questions, and benefits daily from the wisdom of local gardeners.
Ask Ruth © 2010 Ruth Gonzalez & Organic Growers School
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