Test soil before digging into blueberries
Q: We are planning to plant blueberries this year. We’re not berry people, mostly vegetables. Any tips?
• Bob from Poland
A: Yummy, fresh berries are a real treat!
I’m glad you are preplanning, as blueberries are much different than brambles (raspberries, blackberries, etc). Blueberries have different pests, diseases, growth habits — and most importantly, soil requirements.
The first thing any gardener wants to do before planting blueberries is to test the soil and make changes based on the soil test. If you haven’t done a test, wait until late March to take the sample. You can learn more about testing at http://go.osu.edu/soiltesting.
Then, you’ll want to test each year for the first couple of years to ensure you are keeping the pH low. The pH is a measure of the acidity or alkalinity of the soil.
Most soil test pH results show a pH around 6.2 to 6.8 in our area (for gardens). This is too high to grow blueberries, which require a much lower pH of 4.5 to 5.0, with most growers aiming for the 4.5 level when planting.
For the first year, the soil pH can be changed by simply adding peat moss (one cubic foot) to the backfill for each plant when planting. This does not guarantee the pH will be lowered to the proper level, though. Soil sulfur (mostly sold as pelletized elemental sulfur) should be used to lower the pH. The amount depends on the current pH of the soil.
Lowering the pH the year before planting would be the best bet, but as long as you continue to manage the pH, you will be fine. You must keep the pH low for the life of the berry plant. This may mean adding soil sulfur every year or two, depending on your soil test results, which will give you clues as to your soil’s ability to keep the managed, low pH over time. Know that sulfur has 10.4 times the power to reduce pH compared to peat moss.
Learn more about reducing the pH level at http://go.osu.edu/lowerph.
Next, blueberries require lots of organic matter in the soil. The peat moss will provide a good base for this. You can increase the organic matter in the soil using composted plant materials or manure each year. Purchased topsoil is NOT compost. Be sure to use compost.
Finally, blueberries have shallow roots but do not like wet roots. So raised beds are best. You can build a raised bed or simply mound the soil to make one.
Good drainage is paramount. Although they do not like wet roots, they still need water. Most growers find long-term drip irrigation or short term soaker hoses useful to keep the plants watered during summer months.
Diseases and insect pressure are easier to manage than brambles. Pruning is quite different. We have a wonderful factsheet that explains all of these in detail, including the best varieties to choose. Planting several different varieties can lengthen the ripening season for more fresh berries instead of having to pick all at once. Details are at http://go.osu.edu/Blueberry.