Gadenin日本語Get the appNever prune an almond in winter
Almond is a stone fruit and it is pruned in the growing season for one reason: disease. Silver leaf and bacterial canker both enter through open cuts, and their spores are moving in the cool wet weather of the dormant season, when the tree cannot seal a wound. A cut made in midwinter can take months to callus, and by then the infection is inside the limb.
In the growing season the position reverses. Sap is moving, the tree seals a wound within days, and the spore load in warm dry air is far lower. The working rule is to make every cut between the point when growth is clearly under way in spring and about six weeks before leaf fall. Anything you find in winter that genuinely cannot wait, such as a limb broken by snow, gets cut back to a rough stub and tidied properly in spring.
Choose a dry spell, and if rain is forecast within two days, wait. Use clean sharp tools, wipe the blades with spirit between trees, and leave the cuts open to dry rather than painting them, because sealant traps moisture against the wound.
| Season | Prune? | Reason |
|---|---|---|
| Midwinter, dormant | No | Canker and silver leaf enter open cuts, and wounds do not callus in cold wet weather |
| Late winter, buds tight | No | Still the wrong conditions; the tree is about to flower and cannot seal wounds yet |
| Spring, after flowering and in leaf | Yes | The main structural cuts; the tree is growing and seals quickly |
| Early summer | Yes | Thin crowded new shoots and rub out badly placed growth while it is soft |
| Immediately after harvest | Yes | The best time for renewal cuts; wounds close in warm dry weather |
| Autumn, leaves falling | No | Wounds would sit open all winter in exactly the conditions the diseases need |
Where the crop actually sits
An almond carries most of its crop on short spurs, which are stubby side growths a few inches long that flower and fruit year after year. A spur is productive for about four or five years and then declines, so a tree that is cropping well is one that is constantly replacing its old spurs with new ones. Some of the crop also comes from the previous summer's long shoots, particularly on young trees.
That is the whole logic of the job. You are not tidying a shape, you are keeping a supply of young wood coming so that new spurs form close in to the framework. Leave an almond alone for four or five years and the old spurs die out from the inside, the crop moves to the outer shell of the canopy, and the middle fills with bare gray wood.
Because spurs are the crop, an almond is pruned much less severely than a peach, which fruits only on last year's wood and must be cut hard every year. Take out roughly a fifth of the older wood each season and leave the rest. Heavy cutting on an almond removes years of established spurs and pushes the tree into a mass of vertical water shoots that carry nothing.
The three visits, and what each one does
Split the work across the growing season rather than doing it all at once. Three short visits do far less damage than one heavy annual assault, and each one lets you see something the others cannot.
- Spring, once the tree is in leaf: structure Take out anything dead, damaged, diseased or crossing, and anything growing back into the center of the tree. Cut water shoots, the vertical whips rising straight up from the limbs, back to their base unless you need one to fill a genuine gap. Aim for an open center you could throw a hat through, because almonds need light right down into the tree to keep the inner spurs alive.
- Spring, on a young tree: build the framework Shorten last year's leading shoots by about a third to an outward-facing bud for the first three or four years. That forces branching low down and gives you three to five well-spaced main limbs rising from the trunk at a wide angle. Once the framework is set, stop shortening the leaders.
- Early summer: thin the new growth When you can see which shoots are going where, rub out shoots pointing at a wall, straight into the center, or straight up, while they are still soft enough to remove with a thumb. Thin the remaining new shoots so they sit 4 to 6 inches (10 to 15 cm) apart along a limb. Shoots removed with a thumb at this stage leave no wound to worry about.
- After harvest: renewal This is the important cut. Find the oldest, most congested spur systems, the ones with gray bark and short weak growth, and cut them out back to a strong young shoot or to a healthy junction. That young shoot will build the next set of spurs. Take about a fifth of the old wood a year and the tree renews itself on a five-year cycle without ever being cut hard.
- After harvest: open the outside Shorten any limb that has grown too long to support a load of nuts, cutting back to a side branch rather than leaving a stub. Almond wood is brittle and a long unsupported limb splits at its base in the last weeks before hull split, when the crop is heaviest.
Before every cut, look at the base of what you are removing. If there is a strong young shoot already growing there, take the old wood out with confidence. If there is nothing, leave the old wood this year and cut it back to two buds instead, which usually forces a replacement for the following season.
What not to cut
The commonest way to lose an almond crop is to shorten every shoot in the name of neatness. Fat, rounded buds are flower buds and slim pointed ones are leaf buds, and shortening a shoot removes the flower buds along it. A tidy tree in spring is a tree with nothing on it in autumn.
Leave the short stubby spurs alone entirely unless they are dead or crowded into shade. They look like scruffy little twigs and they are the whole crop. People clean them off a limb to make it look smooth and then wonder why that limb bears nothing.
Leave anything you are unsure about. Wood you left this year can be removed next spring; wood you took out cannot be put back, and an almond takes three or four years to rebuild a limb and the spurs on it.
Renovating a neglected tree, and keeping a record of it
If the crop has climbed to the outside of the canopy and the middle is bare gray wood, resist doing it all in one season. Removing more than about a quarter of the canopy at once throws an almond into a thicket of water shoots and opens large wounds that canker will find.
Spread the work over three years, always in the growing season. In the first year, take out one or two of the worst limbs entirely, cutting back to a healthy side branch rather than leaving a stub, and remove the dead and crossing wood. In the second, do the same again and start shortening long bare limbs back to any young growth that has appeared. By the third year you should be able to pick up the normal renewal routine of a fifth of the old wood a year.
Write down each spring which limbs you removed and roughly what proportion of the canopy went with them, and mark which side of the tree you worked on. It stops you overdoing it in the second year, and it tells you honestly whether the tree is answering with young growth low down or only at the tips. Note the date of every pruning session as well, so that if canker does appear you know exactly when the wounds were made.