Prepare and Plant
Once you’ve picked a variety to grow, you’ll need to prepare your ground. Blueberries require well-drained soil that is slightly acidic and rich in organic matter. The soil’s pH should be between 4.5 and 5.5. Strik recommends testing the pH about a year before planting (another reason that July is the best time to start thinking about growing), so that you have time to adjust it if necessary. Tests are available for $20 at Wy’East Environmental Sciences Inc (2415 SE 11th Ave, wyeastlab.net).
Of course, most soil in western Oregon is slightly acidic, particularly near conifers and in undisturbed native soils. But if your soil is in an area that was limed in the past (such as a former lawn or vegetable garden) or is near new construction or concrete (which leaches lime), OSU recommends lowering the pH by adding elemental sulfur, available at Concentrates Inc (2613 SE Eighth Ave, concentratesnw.com) and feed stores like Wilco (multiple locations, wilco.coop).
If you’d rather take the organic approach, mix 3 inches of finely ground conifer bark or sawdust into your soil before planting. Try bagged Black Forest organic compost from Portland Nursery (multiple locations, portlandnursery.com) or fine-grade fir available by the yard from McFarlane’s Bark (13345 SE Johnson Rd, mcfarlanesbark.com). Blend the soil amendment with the native soil over an area at least 3 feet by 3 feet (or 2 feet by 4 feet if planting in rows). This improves drainage and lowers the pH over time. Organic growers will also mix 1 cup of bonemeal into the planting area to provide phosphorus, calcium, and more.
When choosing your planting location, remember that blueberries produce the best fruit in full sun with good air circulation and adequate water (1 inch per week for young plants; 1.5 to 3 inches per week for mature plants), particularly while fruit is forming. Highbush blueberries are best spaced 4 to 5 feet apart and can be planted in beds, rows, hedges, or singles, while lowbush blueberries should be spaced approximately 2 feet apart.
Mulch and Harvest
After planting, mulch your blueberries by spreading about 4 inches of fine fir bark over the root area, keeping material a couple of inches away from the plant’s base. Wait to fertilize your new plant until it has had a chance to settle in: say, late April or early May, with another round in early June and late July. With typical soil, Strik recommends using 1 ounce of ammonium sulfate or urea per plant in each round of fertilizing to lower the soil’s pH and provide nitrogen. Some blueberry growers use organic 8-5-5 in conjunction with 1 cup of bonemeal mixed into the planting area, and a foliar spray of Alaska fish fertilizer three times in September to provide boron and other micronutrients during bud set. Whatever you do, don’t use 16-16-16, a common mistake that slowly kills blueberry plants with salts.
These fertilizers are available at Concentrates Inc, Portland Nursery, and local feed stores. Sprinkle the fertilizer evenly around each plant, away from the crown and stems. Finally, regarding fertilizer: Some folks never use fertilizer and their plants do fine, so don’t fret unless your plant looks sick or doesn’t produce much fruit.
Once bushes produce fruit, blueberries are really easy to harvest: Just pick them ripe and eat them, or toss them straight into freezer bags to enjoy over the next year. Tip: A highbush blueberry reaches maximum sweetness and flavor about four days after it turns blue. Give it a few days to ripen properly on the bush, and you will be rewarded with richer flavor and sweetness.
Blueberry plants can have a productive life span of 50-odd years, providing decades of health, beauty, and sun-warmed fruit eaten by the handful.