How to grow blueberries

What are the best blueberries to grow?

Blueberry bushes can grow to around 1.5m (5ft) tall and wide, but there are also compact varieties reaching just 60cm (2ft) tall that are perfect for growing in containers.

All blueberries produce a better harvest if there is at least one blueberry bush of a different variety nearby, to allow cross-pollination. Most are able to self-pollinate to some extent, however. If you only have space for one blueberry bush, choose one listed as being self-pollinating. Here are a few names to look for:

• Blueberry ‘Top hat’ – a self-pollinating, dwarf variety with good flavour.
• Blueberry ‘Bluegold’ – a self-pollinating, dwarf variety, good for containers.
• Blueberry ‘Northblue’ – a self-pollinating, compact variety, good for containers.
• Blueberry ‘Patriot’ – a vigorous, very hardy variety producing a high yield of tasty berries.
• Blueberry ‘Duke’ AGM – ready to harvest early, so good for northern areas with short growing seasons.
• Blueberry ‘Nelson’, a late season, self-pollinating variety, producing large fruits.

Essential blueberry planting equipment list

To plant blueberries in your garden, you will need…

For planting in soil

1. Spade
2. Soil pH test kit
3. Leafmould, composted pine needles or other acidic compost

For container planting

1. Container at least 30cm in diameter
2. Hand trowel
3. Ericaceous soil or compost such as Miracle-Gro Premium Ericaceous compost

Your guide to planting blueberries

So, when to plant blueberries? The best time to plant blueberry bushes is from late autumn to early spring, in a sheltered position. They produce their best crops in full sun but will cope with some shade.

It’s essential to give blueberries the right soil conditions. They will only grow well in acidic soils with a pH of 5.5 or lower. This is a measure of the soil’s acidity; soils with a pH below 7 are acidic, and those with a pH above 7 are alkaline.

You can test your soil’s pH level with a pH test kit – these are readily available and easy to use. If your soil is only slightly acidic, you can lower the pH by adding sulphur chips. This needs to be done at least a month before planting to allow time for it to take effect. However, the simplest solution to not having the right soil for blueberries is to grow them in a container, where you can control the type of soil used.

How to plant blueberries

1. Before planting blueberries in the ground, dig in lots of acidic organic matter, like leaf mould or composted pine needles, to improve the soil structure and drainage. Don’t use farmyard manure or mushroom compost, as these are too alkaline.
2. Space plants 1.5m apart.
3. After planting, mulch around the base of the plants with pine needles or wood chippings.
4. When planting blueberries in containers, choose a container at least 30cm (12in) in diameter, with good drainage holes. Use ericaceous soil or compost.

Caring for blueberries

Feed container-grown blueberries monthly with a liquid feed designed for ericaceous plants. As far as possible, use rainwater when watering, as tap water will make the soil more alkaline, especially if you live in a hard water area.

If using ericaceous compost in containers, repot your plants every year to refresh the compost. Once the roots start growing through the pot’s drainage holes, repot into a larger container.

Don’t overfeed blueberries grown in the ground, as this will reduce the harvest. Instead, mulch the bushes annually with ericaceous compost, and give them a high nitrogen feed like sulphate of ammonia in late winter.

How to prune blueberries

Make sure you don’t prune blueberry bushes until they are at least two years old, then prune annually in late winter or early spring, following these steps:

1. Remove any crossing or damaged stems.
2. Remove any low branches that trail on the ground.
3. Cut one in every four old stems to the base of the plant. This promotes new growth which will bear more fruit.
4. Remove all twiggy growth on the ends of last year’s fruit-bearing stems, cutting back to a strong upward-facing bud or shoot lower down the stem.

Harvesting blueberries

Blueberries start to ripen from mid-summer onwards. It’s easy to tell when to harvest blueberries, as the fruits turn a dusty blue colour. Leave the berries on the plant for a day or two after ripening to allow them to develop their flavour, and then pick them.

Ripe blueberries should come away easily from the stalks. Fruits ripen at different times on the same bush, so keep checking the bushes and pick the berries as they ripen.

Understanding any potential blueberry problems

Birds

The biggest challenge when growing blueberries is stopping the birds getting to the berries before you do.

• Cover the bushes with horticultural fleece or mesh, but only do this once the berries have started to develop or you’ll stop bees and other insects getting to the flowers to pollinate them.

Powdery mildew

Blueberries can be affected by powdery mildew, a fungal disease that looks like a white powdery deposit on leaves that can reduce the plant’s vigour. It is often a sign of drought stress, so to reduce the risk:

• water regularly.
• Powdery mildew is less of a problem for plants grown in cooler areas.

Frost

In very cold areas, blueberries may need winter protection.

• Cover the bushes with fleece to protect the buds from late frosts in spring or move pot-grown plants indoors.

Key features of blueberries