Blueberries are one of the most delicious of the fresh fruits. I love it when July rolls around, and our blueberry patch opens up. And July 8th is National Blueberry Day! In early July, usually around or near the 4th, we open our patch of blueberries to the public. Its a crazy time. And for the last 10 years, I have been the first in the patch on opening day.
Growing blueberries on a large scale takes a lot of time and perseverance. And patience. Doug Grimm, the founder of Grimm’s Gardens, tried planting blueberries in the sandy soil along the Missouri River before moving the operation to the home farm. He had to move it because it was flooded out along the river bottoms. When he tried to plant them in our heavy clay, high pH soils, he found that you have to change the soil first. And to do that, he used sulfuric acid. Caution: Sulfuric acid is extremely dangerous to handle. Do not use unless you have a background in chemistry and can safely handle it.
Doug used sulfuric acid to permanently change the soil pH on roughly 2.5 acres of land. This is where our blueberry patch is. If you want to grow blueberries in your own backyard, I would recommend using alternative methods to change the soil, or make the soil lower in pH.
Planting Blueberries
Before you plant, you must get your soil correct. Otherwise, you will have poor-growing plants, with possible iron chlorosis, stunting, and poor fruit production. And a weak plant is more prone to disease and insect attacks. So prep your soil in advance, before even thinking about planting.
Once you decide to grow blueberries, determine the best place to plant them. They need full sun, and low pH soil. What is soil pH? Soil pH is the measure of soil acidity or alkalinity, specifically the inverse log of the Hydrogen ion concentration on a scale from 0-14. Neutral pH is around 7, with ‘acids’ being below 7 and ‘bases’ being from 7 to 14. Therefore, a change from a pH value of 5 to a pH value of 4 indicates a 10x increase in H+. Most soils have pH values between 4 to 10.
Blueberries grow best in a soil pH range of 3.8 to 5.5, if your soil organic matter % is on the high side, meaning at least 3%. One way to achieve this is to get an acid potting mix and grow in containers, such as half whiskey barrels or galvanized water tanks. Large raised beds would also be a possibility. Add to the mix peat moss, compost, and shredded or composted leaves (leaf mold). Mix together, then get a sample to a local lab for testing and ask for pH and soil organic matter content. Click here for K-State Soil Lab info.
Keeping the Soil pH Low
To maintain your soil pH in the desired range, you will likely need to do regular testing, at least once per year. To keep it low, add in elemental sulfur each spring and fall. It takes about 6 months for the soil bacteria and microorganisms to change elemental sulfur into sulfuric acid, helping to lower the pH. Topdress each container or raised bed with compost and partially-composted wood chips each spring, being sure not to cover the crown of the plants.
If growing in the ground, I recommend digging a large trench, 16 to 20 inches deep and up to 36 inches wide. Use a mix of 1/3 peat moss (or coconut coir), 1/3 compost, and 1/3 wood chips to the trench, and add elemental sulfur at a rate of 4 cups per 10 square feet of surface area. Water in well and let sit for 4 months. Then get a soil test and determine if you are ready for planting (the pH should be in the 4.5 to 5.5 range for planting).
Picking the Cultivar
Most garden centers sell blueberry plants at various times of the year. Even the bigger box stores sell bareroot plants in the early spring. Try not to go for the “gimmick” plants, such as those with pink fruits or “easy to grow” labels on them. Always do your research on the various cultivars before buying them.
Here in the Central Great Plains region, we have no native blueberries. But we can grow highbush blueberries as long as we take the care to prepare the soil beforehand. There are a number of different cultivars available, and I recommend planting at least 2 in your gardens. Below are some of the more commonly found cultivars.
- Blue Crop – grows 4 to 6 feet tall and ripens early July in Northeast Kansas. It yields 10 to 20 pounds of berries per plant at maturity, which is about 3 to 5 years after planting.
- Blue Jay – grows 5 to 7 feet tall and ripens in late June to early July.
- Chandler – grows 5 to 6 feet tall and ripens in late July.
- Jersey – grows 5 to 7 feet tall and ripens in mid July.
- Patriot – grows 4 to 6 feet tall and ripens in late June to early July.
- Polaris – grows 3 feet tall and ripens in July.
Planting and Watering Blueberries
Once you have the soil prepared (in advance) and your berries picked, your are ready for planting! Now, blueberries have a very shallow root system, so they will need to be watered regularly, especially in dry and hot weather. If you have the ability to put in a drip irrigation system, that would be ideal. Otherwise, plan to have water tanks or a hose nearby for regular watering.
Plant your blueberries with the roots spread out in the soil and do not cover the crown of the plant with soil. Blueberries can be layered, to make new plants. What is layering? Layering is a vegetative propagation technique where the stem or branch of a plant is manipulated to promote root development while still attached to the parent plant. Once roots are established, the new plant can be detached from the parent and planted. Layering is utilized by horticulturists to propagate desirable plants.
Water all newly planted bushes after planting, and again 2 times per week for the first 6 weeks. Then switch to once per week for the first 6 months. You may need to water more often during hot and dry weather periods. Also, be sure to mulch your new plants with partially-composted wood chips. This type of mulch is more likely to retain moisture.
Pruning Blueberries
In the first 2 years after planting, you should not need to do any pruning, except to remove any dead branches. The shoots that grow from the base of the plant are called canes. These canes should be removed at the base when they grow bigger than 3/4 inch in diameter, unless there are less than 20 canes per plant. I like to maintain the blueberry bushes at Grimm’s Gardens with around 18 to 25 canes per plant, removing the largest ones every other year.
Pruning is best done in the winter months, after the leaves have fallen. I start pruning the blueberries here in January and finish sometime in February, depending on how much I have to remove. Large canes can be chopped up for firewood or use to make pens/pencils on a lathe. The smaller canes and dead wood should be chipped and composted or burned.
Problems and Pests
Blueberries are prone to a number of insect and disease issues. Keeping ahead of the insects and bird pressures during harvest can be a big problem for the commercial grower, as well as the homeowner. Birds are problematic when the berries are ripening, because they like to scoop in and eat them. How dare they! One of the most efficient methods for the grower on a small scale would be to use bird netting. You can do this in several ways. You could put netting or each plant individually, or form a structure over the whole patch.
Doug Grimm has also employed shotgun blasters (shooting blanks) and bird predator calls in the patch to scare away birds. It works partially, and there is enough scare-off to prevent most bird feeding.
Insect Pests of Blueberries
There are a number of insect pests of blueberries, which feed mainly on the fruits. If you are growing organic blueberries for fruits or leaves, then the leaf feeders can also be a problem. But again, just like with birds, netting can be a solution for a small grower. There is insect netting which when applied over small rows or plants, can prevent the major pests from getting access to the berries.
Insects pests include Japanese beetles which eat the fruit and leaves, Spotted Wing Drosophila ( a fly that lays an egg in the fruit; then the larvae feeds inside), Cherry Fruitworm Moth (lays an egg in the fruit and hatches a larvae), and Blueberry maggot (a fly with a devastating larva in the fruit). The best prevention of these fruit eating pests is insect netting on the small-scale patch.
Even if you have rows of blueberries, it might be worthwhile to use insect netting over pesticides as a prevention. For pesticides do kill the adult and larvae, but at what cost to the eater? I for one would not like to have my kids ingest fruits tainted with pesticides.
Diseases of Blueberries
While there are quite a few diseases in commercial blueberry production, where there are many hundred of acres of plants together, there are few disease which are detrimental in the home orchard and patch. In seasons where the weather is more wet and warm leading up to harvest, Anthracnose fruit rot can be a serious issue. It starts at the blossom end of the fruit, causing a buildup of pink-colored slime and a sunken appearance.
Other potential diseases include:
- Botrytis blight
- Gondronia canker
- Mummy berry
- Phomopsis canker
- Stem blight
- Stem canker
Controlling these diseases is best done through cultural controls and fungicides. Pruning out the affected areas and deadwood, and cleaning between cuts with alcohol on the pruners or saw can help prevent the spread of diseases. Also, cleaning up infect plants by removing the mulch and leaves in the fall, and applying a new mulch layer will help. A winter or early spring application of copper fungicide or lime sulfur will also help prevent disease pressures.
Enjoying Blueberries
There are many ways in which to enjoy blueberries. The fruit is best when eaten fresh, either right at picking or slightly after. This is when they are at their freshest. I like to jut pop them in my mouth or mix them into a bowl of homemade yogurt. We also freeze about 20 pounds of berries each summer for winter use. Then we make pies, jam, and tarts with them. In the winter, we use frozen berries for yogurt, pie, tea, or just eaten them frozen. My kids love frozen blueberries!
The leaves, if untreated with chemicals, can be used for making tea. It is rich in antioxidants, nutrients, vitamins, and minerals. If picked after they turn red in the fall, then the leaves also have a larger amount of anthocyanins in them. What are anthocyanins? Anthocyanins are a group of antioxidants found in red, blue, and purple fruits and veggies. A diet rich in these compounds may prevent inflammation and protect against type 2 diabetes, cancer, and heart disease.
Conclusion
Blueberries are a nutritious and yummy treat in summer months. You can enjoy eating your own blueberries by preparing the soil months in advance and planning to keep them healthy with insect and bird netting strategies. Having your own blueberries in the garden is rewarding and a treat on its own.
Happy planting!
