Gardening: Growing blueberries in Inland Northwest takes a bit more work
I was on Washington’s west coast recently visiting farms and was impressed by the acres of blueberries planted in the Skagit River delta. Blueberries are one of the major berry crops the region is noted for. I’d love to get lost in those fields with a quart of cream and a bowl come July.
OK, so the cream isn’t the healthiest thing for you, but research has shown that blueberries themselves are high in antioxidants, vitamin C and dietary fiber and only 81 calories for a cup of berries – plain.
We aren’t so lucky in Eastern Washington. They grow blueberries commercially down in the Tri-Cities by altering the soil pH and in a few places in northeast Washington and North Idaho where the soil is acidic enough. Growing them in your garden, or better yet, as a landscape plant takes a little work and planning.
The biggest challenge to growing blueberries in most of the Inland Northwest is that they need an acid soil, and our soil and water tend to be more on the alkaline side. Blueberries prefer soil with a pH of about 4.5 to 5.5. Plants that are grown in pH 7 soils or higher will turn yellow and become stunted.
Before you buy your blueberries, you will need to test the pH of your soil using either a test kit bought at the garden center or by sending samples to a lab. If the pH is close to 6.5 to 7 consider planting your blueberries in containers or raised beds where you can rework the pH more reliably.
To prepare your soil, mix equal parts of native soil, compost, and either peat moss or fine conifer bark and fill your beds or pots. The peat moss and bark will help lower the pH. Then add about two to three pounds of sulfur granules (purchase at the garden center) per 100 square feet of bed to further lower the pH. It’s best to do this in the fall and let the bed sit over the winter for the sulfur to react with the soil.
Check the pH again in the spring and add more sulfur if needed. If you want to plant this spring, however, prepare the soil as described and then plan on adding more sulfur and work it in next spring.
Blueberries need a sunny spot that gets some afternoon shade. Stay away from south-facing walls as they can get too hot and the lime from the concrete can leach out and adversely affect the pH. They will need regular watering as their roots are fairly fine and shallow. Putting them on a drip system and a timer works well. Fertilize them regularly with rhododendron food.
To extend the season, pick varieties that produce fruit as an early, mid- or late-season crop so you get fruit from July through September. Plant two different varieties for each season for proper pollination.
Plants are usually sold as 2-year-old stock and will take about three years to begin producing.
Pat Munts has gardened in the Spokane Valley for more than 35 years. She can be reached at firstname.lastname@example.org.