Among stone fruits, plums are the easiest to grow in Britain. Picking your own tasty plums is a real garden luxury – they’re perfect for training to grow against a wall or fence. Plums make particularly good jam and are also a key to many chutney recipes. Don’t be daunted by a more unusual garden fruit tree, just follow our step by step guide.
When and where
October or November is the optimum time for planting out a plum tree, although you can (if you’re brave) plant out at any time from late Autumn through to early Spring. A moist location in full sun is ideal for plum trees – they need warmth and plenty of light. Avoid areas which retain frost – if your garden is cooler you would be well advised to choose a later flowering variety. A good draining soil is needed. Don’t forget that if your tree is not self-pollinating you will need to plant a pair of trees.
How to plant
If you have a relatively small space for growing your fruit trees, choose a half-size or small variety which you can train against a wall. First of all, soak the roots. Then use a spade to dig a hole which needs to be at least a third wider than the roots, though no deeper; fork over the soil at the bottom of the hole.
You’ll need to stake the tree out, placing a stake next to the root before filling in with soil, mounding towards the base of the tree. Keep the joint and the grafted part of the tree at least 5 cm above the soil level. Firm the soil down gently with your feet, and water in thoroughly. Keep the tree watered until it has established itself in location. Feed regularly.
If you are planting your tree to grow against a wall, plant it around 15 to 20 cm away. Water plum trees thoroughly without water-logging them. Spread fertiliser around the tree, up to 15 cm of the trunk – do this in the early spring.
Plum trees won’t begin to produce fruit until year four or five. The harvesting period will last for around four weeks. Pick your plums once they can be removed easily from the tree. Remove any diseased fruit, as these attract wasps and disease. Ripe plums don’t last well – stored in a fridge they’ll last for a few days. Under-ripe plums will last longer if picked and stored in a paper-lined box to ripen in a dark, cool environment.
Hang up ‘wasp traps’, jam jars of sugary water, to prevent wasps from streaming to feast on your fruit.
Through the year
Prune your plum trees when the fruiting period has ended. Prune away old, dead branches, and prune to keep your chosen shape – fan trained against a wall, or free standing in a pyramid, bush or standard tree-like shape. Pruning will also help ward off silver leaf disease. Pull away any mini-trees (or ‘suckers’) which grow up from the roots. Don’t prune late when the trees are dormant in the winter.
To stop any over-wintering pests, use a horticultural oil-based winter wash in December or January. During the growing season you can use a lighter summer oil, and also protect from moths by applying a grease band at 50 cm above soil level. This is a sticky paper which will stop wingless moths from reaching up into the branches where they will mate and leave caterpillars to eat leaves and fruit.
Thin the fruit on a plum tree in order to concentrate flavour and energy on a smaller, higher quality crop. An over-laden tree producing a watery bounty of plums is an undesirable outcome for most gardeners! Thinning out the fruit will also relieve stress on branches, helping to prevent diseases which enter through points of broken bark.