How To Grow Blueberries: Plant, Grow And Harvest Delicious Blueberries
Guide To Grow Blueberries
Besides being tasty and nutritious, blueberries are also very attractive as well, with beautiful white flowers in spring and a lovely fall colour.
Even if you dont know how to grow blueberries, you can’t do anything wrong. Its very easy to grow blueberries, since the bushes require little attention.
You should always grow them in acidic soil and for best results, you should water them with rainwater. If your soil is not acidic, you can also grow blueberries in pots.
The blueberry bush grows just over two metres in height and is relatively compact, making it a great choice for small gardens.
If you want the best bluberry bushes, you should plant at least two varieties of blueberries close to each other. As a result, you can also extend the harvest season, as some varieties of blueberries bear fruit in July and others in August.
Varieties of Blueberries: Best Blueberry Bushes
Blueberries, cranberries, bilberries and lingonberries all come under the Latin genus of Vaccinium.
North American highbush blueberries are mainly deciduous shrubs 1-2m (3-6 ft) in height. Grown mainly for their fruits, they also have ornamental value, with autumn colour, red winter stems, and small, pretty bell-like flowers in spring. Some cultivars are evergreen in mild areas.
Half-high blueberries are hybrids between Vaccinium corymbosum and Vaccinium angustifolium. They are good patio and container plants, reaching only 45cm-1m (18-38in) in height.
Where To Plant Blueberries
An open, sunny, frost-free, sheltered position is a perfect spot to plant blueberries. Partial sun may do if full sun cannot be provided.
An acid soil is essential (pH 4.5-5.5). Acid sand and peat soils are the natural habitat of wild Vaccinium species. Soils that support rhododendrons, heathers and camellias without effort are usually suitable for blueberries and related fruits.
Rich clays or loams are less suitable, and a chalky or alkaline soil is definitely unsuitable. Neutral soils can be suitably acidified with acidic mulches and fertilisers. On alkaline or heavy clay soils, it is best to grow blueberries in tubs of John Innes Ericaceous compost.
The soil needs to be free of water to grow blueberries and cranberries. Good drainage is essential.
How To Plant Blueberries
Prepare the ground by digging in composted sawdust, composted pine bark. If none of these are available, you can use peat.
Its best to plant Blueberries after leaf fall (November – March).
Tip back the branches and remove any flower buds before planting, so that the plant can concentrate on establishing its roots in the first year of growth. Addition of manure to the planting hole is not advisable.
Mulch newly planted blueberries with composted sawdust, sand, leaf mould, chipped pine bark, or peat (if no alternative is available).
A 1.5m (5ft) spacing between plants is suitable for most blueberries, although some of the most compact varieties of blueberries can be planted at 1m (3ft) spacings.
Container-grown plants usually establish better in the garden than bare-root plants.
How To Plant Blueberries In Pots
For pot growing, start with a plant in a 2-litre pot, and check the rootball every two years to see if it needs re-potting into the next size up of container. A 50-litre pot may be needed eventually.
Read more about: HOW TO GROW BLUEBERRIES IN CONTAINERS
How To Care For Blueberries
Water blueberries with rainwater rather than with mains water. In dry spells, it may be necessary to supplement with mains water. Feeding with an ericaceous fertiliser, and mulching with acidic organic matter is necessary to counteract the alkalinity of mains water.
It is important to water little and often. The most common varieties of blueberries, and in particular cranberries, must not be allowed to dry out. Water the soil under the branches, and apply at the rate of 50-litres per sq m (11 gallons per sq yd), adjusted according to the area taken up by the bushes.
Feed after pruning Blueberries with 50g per sq m of Growmore (or another balanced fertiliser having equal proportions of nitrogen, phosphorous and potassium), plus 15g per sq m of sulphate of ammonia.
Pelleted poultry manure is a suitable organic alternative (apply at 150g per sq m), but as it is usually alkaline, it should be applied with flowers of sulphur (at 15g per sq m) to counteract this alkalinity.
Mature bushes benefit from an additional 50g per sq m of sulphate of ammonia in June, if cropping is heavy or growth is weak. Alternatively, a liquid ericaceous plant fertiliser can be given fortnightly during the growing season.
Mulching with acidic organic matter in spring and autumn helps to keep the pH low, as well as to conserve moisture and keep down weeds. Suitable materials include composted sawdust, composted or freshly chipped pine bark, peat, leafmould and pine needle leaf mould. Avoid manure, mushroom compost, ordinary John Innes compost and wood ash, as these all contain lime and are alkaline in pH. Cranberries respond particularly well to mulching with sharp sand.
How To Prune Blueberries
Blueberries fruit best on wood that is one to three years old, although older branches will also produce a little fruit.
You dont need to prune blueberries for the first three years after planting. Subsequently, bushes are pruned to encourage vigour and to maintain an open centred shape.
Blueberries have two flushes of growth.
In the spring they bear flowers on the tips of the previous season’s growth. These flowers become the first crop of berries. New sideshoots usually develop just below these first berries.
Later in the season (usually July), strong new shoots grow up from the base of the plant, and develop flower and fruit buds at their tips. This second, later crop of buds and berries are usually plumper than the first, producing larger fruits. Production of this second crop of renewal growth and fruit is a sign that the blueberry plant is in good health.
If you want to prune blueberries, you should do so in February or early March, when the fruit buds are visible, but may be done at any time during the winter.
Remove any crossing or horizontal shoots, any weak or twiggy stems and branches, any diseased or damaged growth, and any stems that are dragging on the ground. Remember to remove the twiggy growth at the ends of the branches that fruited last season, effectively tipping them back to a strong, upward-facing bud or branch.
Then cut out one in six of the oldest stems from the base of the plant, removing the woodiest, thickest and most unproductive examples. From one sixth to one quarter of the total growth can be removed from the bush each year.
Hard pruning is recommended, as it tends to result in larger, earlier fruits, and to encourage earlier and more vigorous renewal growth.
After pruning blueberries, mulch the bushes with suitable acidic mulch from the list of choices above.
How To Grow Blueberries: Pollination
Blueberries, cranberries and related berries flower in spring, usually from March to May.
Even the varieties of blueberries that are partially self-fertile benefit from cross-pollination by other cultivars. Three cultivars are recommended for optimal pollination and yield.
Different cultivars flower at slightly different times, but sufficient overlap usually occurs for pollinations to be successful. Some very late season blueberries may not cross-pollinate an early flowering cultivar.
In very cold areas, the earliest flowers can be at risk of frost damage. A double layer of horticultural fleece thrown over the plant will usually provide sufficient extra protection if frost is forecast. Some of the early-fruiting cultivars actually flower quite late but then ripen quickly, so cultivar selection is important in frost-prone areas.
How To Harvest Blueberries
You should harvest blueberries in stages, as they ripen, from late summer to early autumn. Fruit in the same cluster may ripen at different times, and four or five pickings may be necessary over the course of the harvest. Each Blueberry bush generally provides 2-5kg (4.5-11lb) of fruit.
Cranberries and lingonberries ripen later than blueberries, being a mid- and late autumn crop, rather than a late summer and early autumn crop.
Harvest blueberries by rolling the berries between the forefinger and thumb to remove them from their stalks. They should come off easily, and feel soft to the touch.
Fruit generally turns blue and then develops a white surface bloom over a period of a few days. Thats the perfect time to go out and harvest blueberries.
The most common varieties of blueberries have excellent keeping qualities, keeping fresh in the fridge for at least a week.
How To Protect Blueberries From Pests & Deseases
Birds are the main pests, and blueberry bushes will need the protection of a fruit cage, or nylon netting stretched over a wooden frame.
Weeds can be kept at bay with regular hoeing or by application of a contact weedkiller.
Botrytis (grey mould) can be a problem in damp and poorly ventilated sites. We recommend increasing plant spacing, pruning for openness, and improving ventilation.
Phytphothora fungi can affect the roots of Vaccinium plants grown in insufficiently drained soils.
Blueberries are usually trouble free. Vine weevil can be a serious pest of containerised plants, and winter and tortrix moth larvae can occasionally decimate leaves and young fruits.
How To Propagate Blueberries
You can easily propagate blueberries from cuttings.
Semi-ripe cuttings generally grow better on evergreen varieties of blueberries. Sprouting or semi-ripe cuttings are both excellent for deciduous species.
Tear off 15cm-long shoots with an old branch attached at the base of the main stem.
Get rid of all lower leaves, and soak the base in a liquid hormone rooting.
To re-grow your blueberry cuttings, mix 25% soilless ericaceous compost with 75% sharp sand.
The propagator should have a bottom heat of 20 °C, and be partially shady. Four weeks should be sufficient for rooting.