Growing blueberries in containers is so easy and effective that you might want to try it even if you have enough in-ground garden space for this antioxidant-rich fruit. The plants can thrive and bear fruit in containers in any area that receives full sun. Just be aware that growing blueberry plants in pots (or anywhere else) requires some patience. As with most fruit-bearing species, it can take a few years for the plants to produce fruit.
Equipment / Tools
- Watering can or garden hose
- Containers (at least 18 inches deep with drainage holes)
- Blueberry plants of your choice (at least two plants of two different varieties)
- Regular potting mix
- Acidic potting mix
- Organic fertilizer for acid-loving plants
- Bird netting (optional)
Choose Containers and Blueberry Plants
If you've grown other fruit-bearing plants, you know you're in it for the long haul. Your plants can happily produce fruit for years with relatively little care, but you'll want to start them off right. That means planting them in the largest pot possible, one plant per pot. Choose a pot that's at least 18 inches deep with drainage holes. Half-barrels and other deep, wide containers work well for the long term.
When choosing plants, be aware that blueberries need friends. For them to produce fruit, at least two plants of two different varieties are required for cross-pollination; three plants are even better. Place the pots fairly close together, about 2 to 3 feet apart. It’s also a good idea to grow different varieties of blueberries that produce fruit at different times of the growing season to extend your blueberry harvests.
Moreover, it's important to choose a blueberry species and cultivar (cultivated variety) that's right for your climate. The four main blueberry species are: highbush, lowbush, rabbiteye, and half-high. Within these species, there are many cultivars to choose from. To learn which cultivars will thrive in your area, contact your local county extension office, a local farmer, or a nursery professional. You might also decide to choose a cultivar based on the desired size of the fruit. Large berries tend to be good for eating while small berries are usually preferred for cooking.
Prepare the Soil
Blueberry bushes require very acidic soil, and a soil pH between 4.0 to 4.8 is required for the plants to absorb water and nutrients and produce berries. Because most garden soil is not naturally this acidic, planting in containers enables you to better control soil acidity levels. You can easily buy or create an acidic blueberry-friendly potting mix to ensure your plants will thrive
To get started with the right soil mix, fill your pot two-thirds full of regular potting mix and the top third with a potting mix designed for acid-loving plants, such as rhododendrons, azaleas, and camellias. You can find this mix at most nurseries and garden centers, as well as in the houseplants section of some home centers. If you can't find a high-acid potting mix, add fertilizer designed for acid-loving plants.
If you have trouble finding a commercial potting soil for acid-loving plants, consider using the recipe developed by Cornell University. Mix equal parts peat moss and vermiculite, then add in a granular 11-5-11 fertilizer. Test the mix's pH with a simple soil test kit, and adjust the pH level, if necessary, by adding limestone to raise the pH or iron sulfate to lower the pH.
An equally effective potting mix uses equal parts garden soil, well-rotted compost, and coarse sand. Test the mixture's pH balance, and add iron sulphate as needed to increase acidity.
Plant the Blueberries
Plant the blueberries into the containers at the same level they were in their nursery containers. Leave the soil level an inch or so down from the lip of the container. Immediately water the pot thoroughly to settle the soil and eliminate any air gaps around the plant's roots.
Blueberries need lots of water, but they also like sandy, well-draining soil. In other words, they don't like to be sitting in water, so keep the soil consistently moist but not soggy.
When it rains, don’t assume that you don’t have to water your plants. The leaves of the blueberry plant can act as an umbrella, preventing water from making it into the container. So always check the soil with your finger to see whether it’s wet to an inch or two below the surface. If you are not able to water your blueberry plants due to an extended absence, move the plants into a more shaded area to conserve water. It's also helpful to add a layer of compost with a topdressing of pine bark to retain some moisture.
Maintain the Right Amount of Sun
Blueberries need six to eight hours of sunlight per day. It's easy to overestimate how much sun an area gets, so it's important to accurately measure the sunlight in your garden. One simple method is to use a watch to time the hours of full-sun exposure on a typical day during the growing season. However, if you live in an area with very hot afternoon sun, be aware that blueberry plants can overheat. They likely will appreciate some light shade during this part of the day.
You may need to move your containers around during the day to ensure the plants get the required amount of sunshine. With big pots, putting the containers on rolling casters makes it easier to follow the sun.
Blueberries don’t like too much fertilizer. Fertilizing in the early spring typically works well. For organic fertilizer, try blood or cottonseed meal or an organic fertilizer designed for acid-loving plants.
Furthermore, don't just fertilize and forget. Test the soil's pH regularly to ensure it is between 4.0 and 4.8. Because acid washes out of soil over time, you might find that it's more effective to start with a half dose of fertilizer in the spring and then add a light monthly dose throughout the growing season.
Watch Out for Pests
Birds love blueberries just as much as people do. The best way to protect your fruit from feathered poachers is to surround your bushes with bird netting a few weeks before the berries are ripe. Wrapping the plants with bird netting might be cumbersome, but it works.
If yellowing of the leaves occurs, this is probably due to a high soil pH that is causing chlorosis; the solution is to acidify the soil with fertilizer made for acid-loving plants.
Insect and fungal problems can sometimes occur. Make sure to use fungicides or pesticides that are safe for edible plants. Blueberry maggots and cherry fruit worm are occasional problems. While these are treatable with systemic pesticides, be wary of their use, as many are toxic to pollinating insects.
Winterize the Plants
When the growing season is over, protect your plants for the winter season. Blueberries are tough plants, but if you live in a cold-winter climate you should move your containers against a building or into a protected area to keep them out of the wind. You can also mulch your plants with straw or wrap them in burlap. In the winter while the plants are dormant, they don’t need much water. But don’t let them dry out completely.