While the consumption of cultivated blueberries is spreading worldwide, many consumers still appreciate the taste and appearance of wild blueberries, which is characterised by a more pronounced taste, red flesh and smaller berry size.
Wild blueberries are often associated with childhood memories, when on mountain walks the almost black berries were a cheerful refreshment and pastime on hot summer days.
If the differences between wild and cultivated blueberries make you prefer the former, it is good to know that it is also possible to grow wild blueberries: here are some tips for creating a new plant or taking care of an existing one, taken from a recent US publication by the University of Maine.
CREATING A NEW PLANT
LAND
It is important to plant wild blueberriesin well-drained soil, such as sandy soil. Do not plant wild blueberriesin clay soils. Identify the pH of the soil by taking a soil sample.
Apply sulfur to lower soil pH to 4.0 - 4.5; see fact sheet blueberrywild # 254, soil pH management for sulfur application recommendations. Note that sulfur should not be applied when the soil is frozen or saturated or when the leaves of Wild blueberryare wet as you may burn the leaves of Wild blueberry.
To sample your soil, take a box of soil samples and have them analysed by a laboratory or garden centre.
Using a trowel or a small shovel and a bucket, go to the place where you would like to plant the wild blueberriesand collect more soil samples by digging a few small holes three to six inches deep. Repeat at least ten times, then mix these soil samples in a bucket and use the resulting mixture to fill a soil sample box. Take the box and the soil sample form to the laboratory.
TRANSPLANTATION
When buying sod from blueberry, make sure you choose a reputable nursery. The sod is usually available in 10 cm thick blocks of 20×20 cm.
Transplant the root ball to the desired position. Wild blueberriescan be planted as separate plants, in rows or mixed with other plants. Just like rhododendrons and azaleas, wild blueberriesneed full sunlight to grow best. It may be necessary to prune neighbouring plants to maximise the exposure of wild blueberriesto sunlight.
For the first two years of growth, you want the wild blueberriesto put their energy into growing strong roots, so it is necessary to remove all flowers for these first two seasons. As painful as this is, it will substantially improve the long-term health of the wild blueberries.
MULCHING
Spreading mulch in a field at blueberriesadds organic matter and retains moisture, which helps the roots of wild blueberriesto develop. Softwood mulch is a good choice because it is already a lower pH material and is readily available.
WATER
Water or irrigate in the first two years so that wild blueberriescan establish themselves well in a dry season. Wild blueberriesneed 25mm of water per week. If watering, do not provide this water all at once, but spread it out over the course of the week. If there is sufficient rainfall, there is no need to add extra water as this can cause disease.
TREATING AN EXISTING WILD SPOT BLUEBERRIES
PRUNING
Mow the wild blueberrieslawn every second autumn (October to November) to a height of 4 cm. For mowing, you can use a lawnmower, trimmer or flail mower on the lowest setting. Don't worry, 75% of the plant is underground, so you won't damage the plants. Wild blueberriesneed to be mown to produce berries in the quantities we want.
If you want to produce berries every year, you will need to develop a two-year production cycle. Divide your plot in half (approximately) and mow one half of the plot at the end of the season (between October and November), using a lawnmower, electric trimmer or mower. Leave the other half of the area unmowed. In spring, you will see that stems and buds start to grow in your mowed area and, as the season progresses, the stems will become taller but you will not see any berries.
This is known as a 'pruning year' and the objective is vegetative growth for next year's berry harvest. The side that has not been cut back will produce berries. In the autumn, after harvesting the berries, mow this side to produce berries in two years. In short, you will mow half of your plot every year, alternating sides. Berries will be produced every year, but on alternating areas.
Burning plants at blueberryis another way of pruning the plant, however, this is not recommended for homeowners for safety reasons.
WATER
Wild blueberriesneed about 2.5 centimetres of water per week in both the pruning and harvest years. Make sure your plants receive enough water and water as needed.
MANAGING WEEDS
Maintaining a soil pH between 4.0 and 4.5 reduces competition from grasses and broadleaf weeds. Sulphur application may be necessary to maintain an acidic soil pH. For woody saplings (e.g. birch, willow, alder) and ferns (e.g. sweet fern), cutting is the best management option. Cut these saplings and ferns back to the ground three times each year. The aim is to let the plant put energy into above-ground vegetative growth and then cut it back. Cut back the unwanted plant in early summer when it has fully emerged, let the plant grow back again, cut it back again and repeat until the plant stops growing.
GENERAL BEST PRACTICES
ENCOURAGE POLLINATORS!
Wild blueberriesare pollinated by a range of insect species including many species of native bees and honeybees. Invite pollinators to come to your wild blueberries, as opposed to other flowering plants, by planting pollinator-friendly plants that flower throughout the season. Consider how the use of certain pesticides could have a negative impact on pollinator populations.
SUNLIGHT
Wild blueberriesgrow best in full sun. If other plants shade out the wild blueberries, it may be necessary to prune or move those plants. The stems of wild blueberrieslean towards the sun when they do not get enough light.
FERTILISER
Keep in mind that fertilisers can feed weeds just as well as wild blueberries, so it is not always necessary to fertilise. Conventional fertilisers for acidic plants contain soluble ammonium sulphate, which allows nutrients to be absorbed into the acidic soils of wild blueberries. Organic gardeners will want to use products for plants that require acidic conditions, such as those marketed for blueberriesand rhododendrons.
TROUBLESHOOTING
If the plants are not growing or bearing well, start by looking at the following:
- Soils: are they acid (4.0 - 4.5 pH) and well drained?
- Sunlight: is there enough?
- Water: is there enough?
Source: University of Maine: Growing Wild Blueberries in the Home Garden