Plums trees are a really reliable fruit, producing abundant harvests of delicious plump fruit for eating fresh or making into jams, pies and crumbles. Nowadays trees are available that grow to a range of sizes including those that don’t take up a lot of space, so there are choices for even the smallest of gardens.
Jobs to do now
- Keep an eye out for late frosts, protecting blossom if necessary
- Spray for plum sawfly after petal-fall
- Keep on top of weed control at the base of trees
Month by month
Protecting blossom from frost
Cover fan-trained trees temporarily in a tent of horticultural fleece on frosty nights when plants are in flower, holding the fleece away from the flowers with canes.
Plums have a tendency to over-crop and their heavily ladened branches are prone to breaking under the weight of the fruit. Thin out the young fruits in early summer after the natural ‘June drop’. It is often necessary to prop up branches in mid- and late summer, as the crop’s weight can otherwise snap them.
Feeding, watering and mulching
Crops can be greatly increased by appropriate and timely feeding and watering. Water trees during dry spells, especially in early to mid-summer when the fruit is swelling. Apply a mulch of well-rotted manure in mid-spring to help retain soil moisture, keep down weeds, and provide nitrogen. This can be supplemented with a top-dressing of dried poultry pellets or non-organic nitrogen fertiliser such as sulphate of ammonia.
In late winter, feed with a high potassium general fertiliser, such as Vitax Q4. Scatter two handfuls per square metre/yard around trees growing in bare soil, and two and a half around those in grass.Because they can set such heavy crops, plum trees respond well to fertilisers, especially nitrogen. See our guide to feeding and mulching fruit trees.
Plums are generally propagated by grafting or budding. Named cultivars will not come true from seed. Trees grown from seeds or cuttings will be much larger trees than those grafted onto a chosen rootstock, and will be slower to start fruiting.
Pruning and training
Plums fruit on a mixture of one- or two-year-old shoots and older wood, and pruning should be carried out in spring or summer to keep them in good shape, healthy and productive. Pruning of young trees is carried out after bud burst in early spring, while established trees are pruned in summer. Avoid pruning in the dormant season or in mid- to late autumn, to minimise the risk of infection from silver leaf and bacterial canker.
There are three commonly used methods of plum pruning and training: bush, pyramid and fan.
Pruning an open-centre bush tree
Bush-trained plum trees don’t require as precise pruning as apples and pears. However, young trees still require initial training. Plums tolerate having a more crowded crown, although mature trees benefit from some light thinning.
In the first spring, starting with a feathered maiden, choose three or four well-spaced wider-angle side-shoots (laterals) about 75cm (2½ft) from ground level to be the main branches, and shorten these by two-thirds. Prune back the central leader to just above the uppermost lateral. Remove shoots below the selected laterals.
By the second spring or on a two-year-old tree (often offered for sale in plant centres), the main laterals should have produced their own side-shoots, the strongest of which need shortening by half, pruning to an outward-facing bud to develop an open crown. Remove any weak or badly placed shoots. Remove a replacement central leader if one has formed, pruning above the topmost wider-angled side-branch. Bought trees may come with the replacement leader that needs to be pruned out.
In the third spring, continue developing a well-spaced framework as described above.
In the fourth year, switch to summer pruning, as for established trees. Rub out any buds developing on the lower trunk and carefully pull off suckers arising from the rootstock. Pruning is mostly limited to removing crossing, weak, diseased material and strong vertical growth. If the branches are still crowded, then further thinning can be done. For more information, see our page on plum pruning.
See our guide on pruning plums.
Fan-trained trees need regular pruning twice a year, in early summer and after fruiting. See initial pruning of fan-trained trees and pruning established fans.
Cordon training it is not ideal for plums in the absence of truly dwarfing rootstocks. The trees tend to produce strong growth that can be difficult to manage. Cordon training is better suited for naturally less vigorous cultivars such as ‘Early Laxton’, ‘Czar’ and ‘Blue Tit’, grafted on semi-dwarfing ‘Pixy’ rootstock. See our page on growing and training as cordon plums for more information.
Pruning an overgrown or neglected tree
Heavy pruning is best avoided, as larger pruning cuts often do not heal well. Thinning of branches on an old, neglected plums tree should be staged over several years in summer. Aim for a well-balanced crown, keeping the centre free from shoots to allow good light penetration. Aim to prune to a strong existing shoot that is at least one-third of the diameter that you are removing, rather than leaving bare branch stumps that can be prone to dieback. Alternatively, remove the branch entirely. Trees may respond to larger pruning cuts by sending up a mass of new shoots. Where this happens, the shoots will need to be thinned in summer to leave just one or two.
Choosing a plum variety
There are several different types of plums, including greengages, damsons and mirabelles. There are also many cultivars to choose from, for eating fresh or cooking – so if you have limited space, you could buy a dual-purpose cultivar, to get maximum use from the crop. It’s also worth choosing a variety with an RHS Award of Garden Merit (AGM) – this shows it performed well in trials, so should grow readily and crop reliably. See our list of AGM fruit and veg.
Many plum varieties are self-fertile, so a single tree can be planted, but some are not (so are self-infertile) – check with the supplier before buying. Trees that are not self-fertile will need a compatible ‘pollination partner’ nearby – another plum tree that flowers at a similar time – to ensure a good crop. Partly self-fertile cultivars can also produce decent crops and are often cross-pollinated by wild growing cherry plums. In colder areas, choose a late-flowering cultivar such as ‘Blue Tit’, ‘Marjorie’s Seedling’ and ‘Oullins Gage’.
Plum trees are sold either bare-root (without soil around the roots) or in containers. Bare-root trees are only available while dormant, from late autumn to late winter, for immediate planting. Containerised trees are available all year round. Specialist fruit nurseries offer the widest choice of varieties, usually by mail order. Bare-root trees are generally only available from specialist suppliers. Plum trees in containers are also available in garden centres and from other online plant suppliers.
When buying a tree in person, look for a system of well-balanced branches with a strong central leader. You can then train and prune the plant to any of the popular tree forms.
Choosing a plum rootstock
Plums are usually grafted onto rootstocks to limit their size and encourage earlier fruiting, but truly dwarfing rootstocks aren’t available. Where space is limited, consider growing as a fan or possibly a cordon:
Pixy: semi-dwarfing, suitable for cordon or semi-dwarf bush, final height if bush trained 3–4m (10–12ft)
VVA-1: semi-dwarfing, better winter hardiness, improved fruit size and yield, 3–4m (10–12ft)
Wavit: semi-vigorous, suits wide range of soil conditions with some chalk tolerance, 4–4.5m (12–14ft)
St Julian A: semi-vigorous, widely used, tolerant of a wide range of soil conditions, 4.5–5m (14–15ft)
Brompton: vigorous, ideal for ‘full’ standards, height over 4.5m (15ft)
Where to plant plum trees
Thanks to dwarfing rootstocks and restrictive training techniques, any garden can accommodate at least one plum tree, if not more. Plums are usually trained as an open-centred bush tree with a clear stem of 75cm (2½ft). Their ultimate size will depend on the rootstock they are grafted on. Plums can also be trained as a fan against a wall or fence, or as a cordon or a pyramid.
Plums have quite high moisture demands, so are best planted in clay or loamy soils. But the soil also needs to be well drained, as plums hate waterlogging. Add bulky organic matter, such as garden compost, to sandy or shallow chalky soils prior to planting. They also like fertile soil, ideally slightly acidic, with a pH of 6–6.5, but they are tolerant of a wide range of soils, as long as they are well drained.
The following compact dessert (sweet) plum varieties are happy grown in large containers ‘Blue Tit’, ‘Opal’ and ‘Victoria', when on the correct dwarfing rootstock, either Pixy or St Julien A. For good crops ensure that they don’t dry out during the spring and summer and that the pot is large with a depth and diameter of 60cm or more.
Plums are some of the earliest fruit crops to flower. While the trees themselves are often extremely hardy, the flowers can easily be killed by frost, so it’s essential to position trees out of frost pockets and strong winds – a sheltered, sunny spot will produce the best harvests. Japanese plums tend to flower particularly early, so frost protection is usually needed for these. In less favourable situations, consider growing plums as fans against a south-, south-west or west-facing wall or fence.
How and when to plant plum trees
Plum trees are easy to plant, and are best planted during the dormant season, before growth starts in late winter or early spring. Bare-root trees are only available while dormant, for planting straight away, but containerised trees are available all year round – they can potentially be planted at any time, but will settle in best from late autumn to spring.See our step-by-step guides for full planting details:
Video guide to planting trees
Planting trees and shrubs
Compact forms of plum are suitable for growing in large containers if you have limited space. Choose a container that’s at least 45–50cm (18–20in) wide – terracotta pots or half-barrels are suitably heavy and stable. Use a soil-based compost, such as John Innes No.3. For more details on planting in containers, see our expert guides: fruit in containers
Plums develop their best flavour if left to ripen on the tree. If they feel soft when gently squeezed, they are ripe. Trees will generally need picking over several times.
Harvest fruits carefully so as not to bruise them, then eat fresh, destone and freeze, or make the fruits into preserves.
Plums — early autumn
Potential pest problems include plum moth, aphids, winter moth caterpillar. The fruit fly - spotted wing drosophila (SWD) is likely to become an increasing problem.
Plums can be prone to magnesium deficiency
Leaves develop a silvery sheen, cut branches reveal red staining.
Prune from the end of June until the end of August or in early spring. Keep pruning cuts to a minimum, pruning regularly so cut surfaces are small.
The larvae of plum moth and plum sawfly tunnel through fruits making them unappetising. In the case of plum moth, misshapen fruits form and there are droppings within the fruits. Damaged fruitlets often fall in summer.
On small trees it is worthwhile looking for damaged fruitlets in May. These should be removed before the larvae complete their feeding and go into the soil. Pheromone traps capture male moths and might help protect isolated trees.
Brown rot is a fungal disease causing a brown, spreading rot in fruit, sometimes with white pustules of fungi on the surface. It is usually worse in wet summers.
Remove all rotten fruit as soon as you see it and destroy, this will prevent the spread of the rot.
All tree fruits are prone to wasp damage. As their fruits ripen, the high sugar content attracts wasps, which not only damages the fruit but also poses a threat to gardeners.
Hang wasp traps in trees and harvest crops as soon as they ripen. Avoid leaving windfalls or over-ripe fruit on the ground.
Nigel Slater says damsons are the best type for this ice cream recipe, but any rich-flavoured plums can be used.
Mary Berry offers this delicious chutney recipe for when plums are in season.
The Royal Horticultural Society is the UK’s leading gardening charity. We aim to enrich everyone’s life through plants, and make the UK a greener and more beautiful place.