Grow Your Own Blueberries

Author: Claire Leduc, Master Gardeners of Ottawa-Carleton; published with permission

There are not many treats better than fresh berries. Ripe blueberries are no exception. Growing your own blueberry plants is not too difficult once you understand their particular needs.

Soil Preparation

Fall is a great time to start preparing for spring planting. Blueberries grow best in the sun but tolerate light shade.

They can be a bit fussy about soil, preferring a light sandy soil. If you have heavier clay soil, you can use a raised bed where you can control the soil. Blueberries also need acidic soil with a pH between 4.0 and 5.5 (compared to between 5.5 and 7.0 for most other plants).

Once you have picked a location, make sure to test your soil’s pH to determine whether or how much to adjust it. Lowering pH can be challenging. The safest and most effective strategy is to mix elemental sulfur in the top 20 cm of soil. The required amount depends on your soil pH test results. This adjustment takes several months of fairly warm weather to take effect, so start early.

In a pinch, it is also possible to mix in moist peat moss at planting time, but only Canadian sphagnum peat moss has a pH low enough to have an impact. However, it is not always readily available, not to mention the environmental impact of harvesting it.

Choose Your Plants

There are many species of blueberry plants, all part of the Vaccinium genus and North American native plants. The high bush blueberry grows 1.8 m high, while the low bush, known as “wild” blueberry, grows to only 30 cm. Crossing these two species has bred newer varieties, known as half-high blueberries, which grow between 45 cm and 1.2 m. Their flavour tends to be a bit less sweet, but it is still delicious.

The plants are all self-fertile but do need the help of pollinators to produce fruits. Bumblebees are particularly attracted to the bell-shaped flowers. For optimal pollination, it is better to have at least two different varieties within the same category (high, low, or half-high bush).

To extend the harvest season, you can also choose blueberry plants that have different maturity dates, as long as they flower at the same time.

The First Three Years

Growing blueberries requires patience. In addition to the first soil pH test, another test is necessary before planting to ensure the level is in the acceptable range. When planting, make sure to space the plants according to their mature size to avoid overcrowding. Be sure to water regularly during the first few years, as blueberries have a shallow root system. Adding compost or manure helps with nutrients and water retention. Mulching around plants helps maintain moisture and reduce weed competition.

As blooms appear during the first three years, promising delicious blueberries, you will have to sacrifice them by pinching them off for the sake of a stronger and more productive plant in the future.

It is also recommended to do a pH test every two years while you become familiar with the acidity of your soil. It will have a natural tendency to return to its original pH.

The blueberry bush will continue to send up new stems from the root base. Very little pruning will be required in the first few years. When the plants are still dormant in the spring, remove broken or unusually spindly stems and continue adding compost at the base.

After Three Years

Once your blueberry shrubs are well established, you can finally leave the spring blooms and enjoy the blueberries that will soon follow. However, pruning becomes an important annual task in early spring, before the leaf buds open. You can cut back (to the ground) broken, overly spindly, and older branches (five or more years old, which become less productive). This will let younger stems take over, improve air circulation, and let light penetrate. On high-bush and half-high plants, it is good practice to keep 4 to 6 mature stems and 2 to 3 new shoots per plant. This approach will ensure the plants stay vigorous and productive.

Continue monitoring the soil for acidity and amending as necessary. Adding compost or manure annually and keeping a layer of mulch around the plants will also contribute to their long-term health.

In addition to delicious berries, blueberry plants are very attractive shrubs with their glossy green leaves that turn bright colours in the fall. There are many varieties to choose from. Some even produce pink blueberries like the ‘Pink Lemonade’. The ‘Jelly Bean’ blueberry has particularly attractive foliage and stays compact. If you prefer the typical blueberry plant, the choice is yours. You are sure to find a variety to suit your needs.