RHS Growing Guides
How to grow blueberries
Our detailed growing guide will help you with each step in successfully growing Blueberries.
Getting Started
The main thing to remember is that blueberries need acid soil, with a
Blueberries like lots of sun and moist soil, so don’t let them dry out during the growing season, especially while flowering and fruiting. Birds love the berries too, so once they start to ripen, protect them with netting, or grow plants in a fruit cage.
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Choosing
There are many blueberry varieties to choose from, fruiting at slightly different times between early and late summer, or producing plants that grow to different sizes, from about 50cm (20in) up to 2m (6½ft). Less vigorous, compact varieties, such as ‘Bluetta’ and ‘Sunshine Blue’ are best for containers and small gardens. Also look for varieties with an RHS Award of Garden Merit (AGM), which shows they performed well in trials.
Most blueberries are partly or fully self-pollinating, so you only need one plant to produce a crop. However, cross-pollinated plants tend to produce larger harvests, so if you have room, plant two or preferably three different varieties.
What and where to buy
Blueberries are widely available in garden centres, fruit nurseries and from online stockists. They are sold as young plants in containers of various sizes, available all year round.
Recommended Varieties
Flowers late but crops early, so very suitable for northern areas. Good crop of medium to large berries. Partly self-fertile.
Very hardy, early- to mid-season blueberry with large, sweet fruits. To crop well, it needs another blueberry variety nearby.
Self-fertile, compact plant, ideal for containers. Dark blue fruits in mid-summer.
Preparing the Ground
Blueberries must be grown in acid (or ericaceous) soil or ericaceous potting compost, with a pH of 4.5–5.5. Test your soil’s pH to make sure it’s suitable – kits are available online and in garden centres. If your soil is only slightly acidic, you can lower the pH by adding sulphur chips, ideally the previous summer or autumn.
If you have alkaline soil or heavy clay, grow blueberries in large containers or raised beds (15–20cm/6–8in high) filled with ericaceous soil or ericaceous potting compost.
Improve your soil before planting by digging in lots of bulky, acidic organic matter, such as pine needles, leafmould, composted conifer bark or bracken. Avoid well-rotted farmyard manure or mushroom compost, which are too alkaline for blueberries.
Planting
Blueberries can be planted in the ground (in acid soil) and in containers of ericaceous compost. They will settle in best if planted while dormant, between autumn and spring, although they can be planted at any time of year, except in hot, dry weather or into frozen ground. Choose a sheltered planting site in sun or light shade, with well-drained but moisture-retentive soil that doesn’t dry out in summer or get waterlogged in winter. A sunny spot should give you a better crop and good autumn leaf colour.
Planting in the ground
Blueberries are simple to plant – see our step-by-step shrub-planting guide below. Plant blueberries at the same level they were previously growing, and 1–1.5m (3¼–5ft) apart, depending on the variety’s ultimate size. After planting, apply a thick layer of ericaceous mulch, such as pine bark (composted or chipped) or leafmould, leaving a gap around the base of the stem.
Planting in a container
Choose a compact blueberry variety, such as ‘Bluetta’ or ‘Sunshine Blue’, and use ericaceous (acidic), soil-based, peat-free compost. The container should be at least 30cm (12in) in diameter for a young plant, and 45–50cm (18–20in) for a larger plant. Planting is easy – see our step-by-step guide below.
Plant Care
Watering
Blueberries must be kept moist (but not soaking wet) throughout the growing season, so make sure they don’t dry out. Plants in containers, in particular, need regular watering – even daily in hot weather. Use rainwater from a butt, rather than tap water, unless you have no alternative in a drought. Tap water is usually too alkaline, especially in hard water areas.
Feeding
Plants in containers – feed once a month through the growing season (April to September) with a liquid fertiliser specifically for ericaceous plants
Plants in the ground – in late winter apply a high nitrogen feed, such as sulphate of ammonia, at a rate of 15g (½oz) per square metre/yard. Check the soil pH every spring – it should be pH5.5 or lower – add sulphur chips if it’s too high and apply an ericaceous mulch annually (see below). If your blueberry isn’t growing well, apply an ericaceous fertiliser, but take care not to overfeed, as blueberries dislike excess fertiliser. Poor growth could also be due to unsuitably alkaline conditions, excess nutrients and fluctuations in soil moisture
Mulching
Mulch blueberry plants in spring or autumn with a 7–8cm (2½–3in) layer of acidic or neutral organic matter, such as composted sawdust, composted or freshly chipped pine bark, composted pine needles or leafmould. This helps to keep the soil acidic and holds in moisture. Avoid manure and mushroom compost, as they tend to be quite alkaline.
Winter protection
If a late frost is forecast while blueberries are in flower, move potted plants indoors overnight, or cover plants with hessian or an old bedsheet, removing it during the day to allow insects to pollinate the flowers.
Repotting
Young plants that are initially in a 30cm (1ft) wide container should be repotted into a larger, 45–50cm (18–20in) pot once roots start to appear through the drainage hole in the base. Use a soil-based, peat-free, ericaceous (acidic) compost.
Propagating
New blueberry plants can be grown from cuttings:
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Deciduous species (which lose their leaves in winter) can be propagated from softwood cuttings in late spring or semi-ripe cuttings in late June to early July
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Evergreen species grow better from semi-ripe cuttings, taken in late June to early July
Pruning and Training
Pruning is rarely needed in the first two years after planting – just remove any crossing or unwanted branches if necessary.
After that, prune at any time from November to March, but ideally in late February or early March when the fruit buds can easily be distinguished from leaf buds. Fat buds produce flowers and fruit, while smaller, flatter buds form shoots and leaves – aim to retain branches with lots of fruit buds.
A mature blueberry bush should comprise about one-third old stems, one-third middle-aged stems and one-third young stems.
When pruning, remove:
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Dead, diseased, damaged, weak or rubbing stems, plus any that are touching the ground
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Twiggy growth at the ends of the branches that fruited last year, cutting back to a low, strong, upward-facing bud or branch. This encourages side-branching
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Up to a quarter of the oldest and thickest stems, making your cuts at the base of a mature plant or just above a younger strong shoot lower down on the branch. This encourages plants to send up new stems from the base, to keep them productive
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Any new stems produced in the previous summer that have failed to ripen and have died back to leave hollow wood and dead tips. This often happens in colder parts of northern England and in Scotland. Cut back affected shoots to healthy wood, 15cm (6in) from the base
Harvesting
Problems
Blueberries are generally healthy and trouble-free, as long as they’re grown in suitably acidic soil or ericaceous potting compost, and kept well watered throughout the growing season. They need protection in very cold spells in winter, especially when grown in containers, and from frosts while in flower in spring. Make sure the fruits are protected from birds too, with netting or a fruit cage.
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