Growing Blueberries

With the recent availability of a reasonable number of very good varieties for the amateur fruit grower, blueberries have become very popular for growing at home or in the allotment. However, at this early stage there has to be a word of caution here as blueberries will only be successful if grown in an acid soil. If you have a neutral or alkaline soil you will only be able to grow them in pots or containers using ericaceous compost and fortunately many blueberry varieties make very good container plants. If you have any doubts about the acidity of your soil you can check it out easily by purchasing a soil testing kit from your local garden centre. You are looking for a pH between 4 and a maximum 5.5 and anything higher than this is unsuitable. If you can grow azaleas, camellias and rhododendrons well you should be able to grow blueberries.

Blueberries need plenty of sun and are ideally located in sunny conditions or partial shade. If grown in too much shade the berries will simply not ripen. Blueberries do need plenty of moisture in the summer months so be aware of this when identifying suitable locations for the plants. Although blueberries can be fairly hardy heavy frosts can damage the blossoms so cover the plants with fleece or similar when late spring frosts are forecast remembering to take off the protection during the daytime.

Although most blueberries are self-fertile or partially self-fertile it is best to grow at least two but preferably three different varieties to ensure reliable cropping.

If grown in the ground blueberries need a good free draining soil with plenty of composted bark, leafmould, pine needles or sawdust worked in before planting. This is particularly important as in wet weather the planting hole could act as a sump and one thing that blueberries do not like is having their roots in the wet during the winter. Remove all weeds before planting and space the plants around 1.2-1.5m (4-5ft) apart. After planting mulch well with a good layer of well-rotted pine bark or leafmould.

Young blueberry bush growing in a fruit cage.

If your soil is not acidic enough you can grow blueberries in raised beds of ericaceous peat but this can be a very expensive option and pots or containers may be a far more suitable option. If you are planting in pots you should consider something that is 38-45cm (15-18in) in diameter. Ensure that pots have good drainage holes in them and add a good layer of crocks, stones, gravel etc. to ensure very good drainage. Only use ericaceous compost for planting and then mulch at the top with well-rotted pine bark or leafmould.

It is quite likely that you will need to do very little or no pruning during the first two or three years other than to remove any damaged, diseased or dead growth. With a mature plant you should aim to have one third young, one third middle aged and one third old growth. When pruning is required it is best carried out in late February and early March when fruit buds are beginning to swell so you can easily identify what growth not to remove.

As noted earlier blueberries need plenty of moisture during the growing season. The issue here is that in areas of hard water it becomes very alkali and therefore unsuitable for watering blueberries. To overcome this you either need to use rain water only procured from water butts or hard water taken from the tap to which a conditioner such as Ericaceous Feed has been added and which is obtainable from Pomona Fruits; it is essential that the compost in pots and containers do not dry out. Ensure that you feed plants in pots and containers at least monthly.

There are a number of very good varieties which you should consider planting:

Bluecrop is probably the most widely grown blueberry in the UK and produces large, well flavoured berries. The berries are ripe from early to mid-July and the added bonus is that the leaves turn a beautiful orange red in the autumn.

Chandler produces huge berries which have a wonderful luscious flavour. The berries ripen from mid-July and will be available for up to six weeks.

Duke is one of the heaviest and most reliable cropping blueberries and has received the Award of Garden Merit from the Royal Horticultural Society. This variety also has the advantage of flowering late so is very suitable for northern areas and areas subject to frosts. The berries ripen from early July.

Herbert is a variety that has deservedly been around for some time. The plants can be quite vigorous so this variety is best planted in the ground rather than in a container. The berries can grow quite large a develop a good flavour and unlike many other blueberries which fruit in July, Herbert ripens from mid-August.

Ozarkblue is a variety ideal for planting in containers as it is a moderately vigorous plant and it has the benefit of producing well flavoured and large growing berries. This is another variety which ripens from mid-August.

Spartan is another blueberry which has received the Award of Garden Merit from the Royal Horticultural Society. The berries can grow quite large and have a very good flavour. In the autumn the foliage is particularly attractive as the leaves turn to orange and yellow. The berries ripen from early July.

Sunshine Blue is a newly introduced dwarf blueberry that is perfect for container growing. The flowers can be quite attractive and the leaves will usually remain on the plant during the winter. The berries are medium in size and have a very good flavour. They ripen from mid-July. This variety can crop abundantly from year one and it is important that you thin out the fruits until its fourth year. It is imperative that the plant is able to grow away well and not be needing to put the majority of its energy into fruit production. I can assure you that the resultant fruit will be larger and the plant should be long lived!

Gerry Edwards
3rd June 2013

Gerry is an experienced amateur fruit grower who is Chairman of the RHS Fruit Group, a member of the Royal Horticultural Society’s Fruit, Vegetable and Herb Committee and also their Fruit Trials Panel. Gerry judges fruit nationally for the Royal Horticultural Society and is also a qualified National Vegetable Society judge.