Blueberries: Tips for growing quality bushesMay 11th, 2011 | Category: Growing
by Chris Elder
Growing blueberries in our area is as regular as the rain. Northwest counties grow acres and acres of this popular berry, with Whatcom County leading the way. Washington state ranks sixth in the nation for production, while North America grows roughly 90 percent of the world’s blueberries with over 50 percent going straight to fresh produce markets.
Locally, home growers and gardeners are becoming more interested in nutritious edibles, with berries at the top of the list. Have you thought about growing blueberries? Here is some information to get you started.
Preparing the soil
Blueberries generally enjoy full sunshine but will often tolerate partial shade, and prefer worked soil that drains well. When determining how many bushes to plant, most people want two to three bushes per person, though anyone with children should probably plant a few extra. (It’s hard to pass a ripening blueberry bush and resist eating them on the spot.)
When planting blueberries, site preparation is critical. Blueberries like acidic soils, meaning soils with a low pH (generally in the 4.5 to 5.5 range) and a higher concentration of organic matter. A pH test can be obtained at certain nurseries and hardware stores, or you can have the pH tested through a standard soil test. Consult your local nursery or the WSU extension office for soil testing options.
To decrease your soil’s pH, thus increasing your soil’s organic matter, there are several options. When planting blueberries some experts recommend removing one-third to one-half of the soil and replacing with peat moss. For raised beds or growing blueberries in containers, a mix of half peat moss and half acid compost or soil mix should work well. To make your own soil mix, try 50 percent peat moss, 40 percent bark mulch, and 10 percent sand. Coco coir is regarded as a more sustainable alternative to peat moss but will require the addition of some nutrients.
Blueberries are acid lovers and will respond well to the addition of coffee grounds, wood ash, or Epsom salts.Watering the ground around the blueberries with a solution of one tablespoon of white vinegar to one gallon of water can also increase soil acidity.
In the ground
To plant blueberries, dig a hole larger than needed, remove the plant from the pot, and rough up the roots to encourage new root growth. Situate the plant about a half-inch above the regular soil grade and firm up the dirt around the root ball. Be sure to water well after planting.
Blueberries can be planted as close as two feet apart to form hedges or closer to four or five feet apart for more individual bush development.
Blueberry bushes are pollinated by bees. Bumblebees and solitary bees are indigenous pollinators, though honeybees are utilized for commercial blueberry pollination. All blueberry plants have male and female organs on each flower, but many varieties are not self-pollinating and must have another blueberry variety within 100 feet for a healthy fruit set.
Once planting is complete, mulching is the next step to establishing healthy, happy plants. Mulch around your bushes with two to four inches of bark mulch, acid compost, sawdust, or grass clippings. Be sure to avoid using aromatic mulches such as cedar or redwood due to their growth inhibiting qualities. If grass clippings are used as a mulch, be sure to mix with bark or straw. Remember to check mulch in the fall as it can also serve as safeguard from cold temperatures and winter damage.
Blueberries have a shallow, fibrous root system and with mulching weed pressures are reduced and soil moisture content can remain at a more consistent level. This shallow root system also means it is important to keep your plants well hydrated. Once the weather warms, watering two to three times per week will help keep plants healthy, vigorous, and producing quality fruit.
Wait to fertilize your bushes until after they are established. Fertilize twice per year in early and late spring.Acidic fertilizers can be used according to the directions on their label. Also high-nitrogen fertilizers such as blood meal and cottonseed meal will work well with blueberries. Avoid non-composted manures as this can shock and damage the plants. (Also, consider the thrifty option of occasionally scattering your coffee grounds as a top dressing around your plants.)
When planting young plants, it is a good idea to remove all or almost all blossoms. This encourages root growth over fruit production and will ultimately give you a better established plant and better fruit next year.
After the first year, pruning older branches that bear little to no fruit will result in the production of new wood that will produce larger, more abundant berries. Remove deadwood and non-vigorous twigs. Select for bright healthy-looking wood with longer lateral branches.
If you have transplanted plants, especially larger bushes, it is important to keep them well watered and also to prune them, hard. Some people will cut off the entire top and let the plant start from scratch. This seems extreme to some, but pruning by one-half to two-thirds is probably a good idea.
Growing blueberries is a fun and tasty way to grow some food and create an attractive landscape. Contact your local gardening center to learn about the best varieties in your particular climate, as well as small-space growing (containers), traditional plants, or for something more unique (such as the brand new pink-berried ‘Pink Lemonade’). Many nursery centers also have blueberry workshops coming up, including Bakerview Nursery in Bellingham, which is holding a free workshop on Saturday, May 28 at 10 a.m. titled “Blueberry Magic.” Good luck and have fun!
Chris Elder lives with his family in Bellingham. He organizes Bellingham Urban Garden Syndicate (BUGS).