Love Affair with Blueberries

Following is the latest in the series by Linn County Master Gardener, Lisa Slattery, on pruning in Iowa home gardens:

This week we're talking about blueberries, which I absolutely love! My love affair with blueberries started when I was little. I grew up in East Central Illinois and one of our summer rituals was picking blueberries. I don't mean just enough for a pie, but gallons and gallons worth each July. We'd stuff ourselves in the field and have blueberries for the rest of the year in the freezer. We picked berries at a blueberry farm, where we rode trucks out into acres and acres of blueberry bush fields. The nice thing is that you don't have to visit a berry farm to have summer blueberries, they will grow in Iowa if you select the right varieties for the home garden, give them the growing conditions they like and prune them correctly.

Blueberry plants are shrubs like currants and gooseberries. There are highbush and half-bush varieties that can be grown in Iowa. The highbush blueberries are hardy in central and southern Iowa. Suggested varieties are ‘Blueray', ‘Bluecrop', and ‘Patriot.' These bushes can reach heights of 6 to 8 feet tall. Half-bush blueberries are a bit more cold hardy and usually only reach 2 to 3 feet in height. Some suggested varieties are 'Northblue', 'Northcountry', 'Northsky', ‘Polaris' and ‘St. Cloud.' Blueberries require a sunny location, well-drained soil and like an acid soil PH of 4.0 to 5.5 which you can create by incorporating Canadian sphagnum peat into the soil. Sulfur can also be used but should be applied a year before planting. Highbush varieties should be spaced 4 to 6 feet apart and half-bush varieties can be planted 3 to 4 feet apart.  

Blueberries should not bear fruit for the first two years, so remove any blossoms that form to maximize vegetative growth and increase future yields. Blueberry bushes will come into full production within 5 to 6 years. Blueberries require less specific pruning than other small fruits. Yields and fruit quality decline when blueberry shoots (stems) reach 5 years of age. In late winter/early spring, prune out any dead or diseased stems. Also, prune out stems that are 5 years old and older. Allow one to two new shoots to develop each year.

Birds are the biggest threat to blueberry bushes so use netting to protect your berries (once the fruit begins to turn color) from being devoured before you can bake your blueberry pies!