How to Prune a Peach Tree: Why It Must Be Done in the Growing Season

Peaches fruit on last year's wood, and nothing else

This is the fact the whole job turns on. A peach flowers and fruits on shoots that grew during the previous summer, and each of those shoots fruits once. Once a length of wood has carried a crop it will never carry another; it just gets longer and woodier and puts its new growth further out at the tip.

Leave a peach alone for three or four years and you can see exactly what that means. The center of the tree fills with bare gray wood, the leaves and the fruit sit in a shell around the outside, and the crop climbs out of reach. Nothing is wrong with the tree; it is doing what it always does. Pruning is the only thing that keeps forcing new shoots to appear close to the trunk.

So the aim of every cut is the same: remove wood that has already fruited, and leave young shoots that have not. You are running a rolling replacement, not tidying a shape.

Never prune a peach in winter

Stone fruit is pruned in the growing season, and the reason is disease. Silver leaf and bacterial canker both enter through cuts, and their spores are about in cool wet weather while the tree is dormant and unable to seal a wound. A peach cut in midwinter can take months to callus, and by then the infection is inside.

In the growing season the picture reverses. Sap is moving, the tree seals a wound within days, and the fungal spore load in warm dry air is far lower. The practical rule is to make every cut between the point when the buds are clearly swelling in early spring and about six weeks before the leaves fall. Anything you notice in winter that genuinely must go, such as a branch broken by snow, gets cut back to a stub and tidied properly in spring.

Pick a dry spell, and if rain is forecast within two days, wait. Cut with clean, sharp pruners or a saw and wipe the blades with spirit between trees. Leave cuts open to dry rather than painting them with sealant, which traps moisture against the wound.

The replacement cut, done three times a year

In practice you visit the tree three times, and each visit has a different job. None of them takes long once the framework is established, and all three together do far less damage than one heavy annual assault.

1. Early spring: take out the dead and the crossing wood As the buds swell, remove anything dead, damaged, diseased, or growing back into the middle of the tree. Cut water shoots, the vertical whips growing straight up from the branches, right back to their base unless you need one to fill a gap. Aim for an open center you could throw a hat through.
2. Early spring: shorten the framework branches On a young tree, cut back last year's leading shoots by about a third to an outward-facing bud. This forces side shoots low down, which is where you want next year's fruiting wood. On an established tree the framework is set and you leave the leaders alone.
3. Early summer: reduce the new shoots Once fruit has set you can see which shoots are carrying. On a fan, rub out shoots pointing directly at the wall or straight out from it while they are still soft enough to remove with a thumb. On a bush, thin the new growth so shoots sit about 4 to 6 inches (10 to 15 cm) apart along a branch. Crowded shoots shade each other and none of them ripens properly.
4. After harvest: cut out the wood that fruited This is the cut that keeps a peach productive. Find the shoot that has just carried fruit, follow it back to a strong young shoot growing near its base, and cut the old one out just above that young shoot. The young one is next year's crop. Tie it in on a fan; on a bush just let it stand.
5. After harvest: leave the tree open going into autumn Take out anything crossing or crowded so the tree carries less wet foliage into autumn. Do not shorten the young replacement shoots; the fruit buds are along their length and cutting the tips off costs you next year's crop directly.

The single most useful habit is to look at the base of each shoot before you cut anywhere. If a strong young replacement shoot is already growing there, you can remove the old wood with confidence. If there is nothing, leave the old shoot and cut it back to two buds instead, which will usually force a replacement for the following year.

What not to cut

The commonest way to lose a peach crop is to shorten every young shoot to make the tree look neat. Those shoot tips carry the flower buds. A tidied tree in early spring is a tree with no fruit in summer.

Learn to read the buds instead. Fat, rounded, slightly furry buds are flower buds. Slim, pointed, flat-lying buds are leaf buds. Along a healthy one-year-old shoot they usually sit in threes: a leaf bud with a flower bud on each side. A shoot with only pointed buds is all leaf, and it can go if the tree is crowded.

Also leave alone: any shoot growing from a low, well-placed position that you can use to bring the crop back in towards the trunk, and any branch you are not certain about. Wood you left this year can be taken out next spring; wood you removed cannot be put back, and a peach can take three years to rebuild a limb.

Renovating a tree that has been left alone

If the crop has climbed to the tips and the middle is bare, resist the urge to fix it in one go. Removing more than about a quarter of the canopy in a season pushes a peach into a mass of water shoots and greatly raises the risk of canker getting into the big wounds.

Spread the work across three springs. In the first, take out one or two of the worst branches entirely, cutting back to a healthy side branch rather than leaving a stub. In the second, do the same again and start shortening the remaining long bare limbs back to any young growth that has appeared. By the third year you should be able to pick up the normal replacement routine.

Keep a note each spring of which limbs you removed and roughly how much of the canopy went. Written down, it stops you doing too much in the second year, and it tells you honestly whether the tree is responding with young growth low down or only at the tips.