Almond Trees Can Be Tricky To Grow – Here Are Some Important Guidelines

TREES > ALMOND

This may come as a surprise to some but the almond tree, originating in the Middle East, can be grown in quite a few regions of England.

Though an almond tree is certainly more of a challenge to grow in English gardens than, say an apple tree or a cherry tree, think of those fragrant pink blossoms in spring and an easy harvest of garden-grown almonds!

We may think of almonds as nuts along with hazels, walnuts, and pistachios.

What a surprise, then, that the almond’s kith and kin are not any of those nuts, but, peaches, plums, and apricots!

All of these fall within the genus Prunus and are called ’Stone Fruits’.

Though a few species of wild almonds exist, Prunus dulcis is the only domesticated or cultivated almond species.

Almost all almond trees commercially grown for the nut are Prunus dulcis cultivars.

As for calling the almond a ‘nut’ – this is not strictly correct. It is the kernel or seed of a drupe – a type of fruit or pod.  

Overview

Botanical Name	Prunus dulcis
Common Name(s)	Almond Tree
Plant Type	Fruit Tree
Native Area	Middle East
Hardiness Rating	H5/H6
Foliage	Deciduous
Flowers	Spring blossom
When To Sow	February, March, November
Flowering Months	March, April
Harvesting Months	September, October
When To Prune	March, July

P. dulcis, a deciduous tree, typically grows to 4 to 6m with the crown having a similar spread.

The leaves are lanceolate and of a rich, deep green shade, turning yellow and orange in the autumn.

Sizes vary quite a bit and can reach 12cm.

In spring, clusters of small pale pink, sometimes white, bowl-shaped flowers emerge, attracting bees and birds as well as appreciative human eyes.

The pleasant blossoms give way to the fuzzy taupe-green drupes that enclose almonds.

In autumn the hulls will start to split, signalling that it is time to begin your almond harvest. 

An almond tree does not need to be grown solely for the almonds.

Depending on the variety (and how you prune it) it will provide some summer shade, letting through dappled sunlight.

And regardless of variety, this ornamental tree will provide pretty foliage with yellow and orange autumn colour, delightfully pretty blossoms in spring, and a rich fragrance to enliven the garden.

You could almost consider the almonds a bonus. 

A Note On Ornamental Types

And as it happens, there is such a thing as an almond tree without almonds!

Dwarf flowering almond trees are small ornamental trees that produce a profusion of scented blooms.

However, they do not produce almonds (or any edible fruit, drupe or seed).

This article is primarily about ‘real’ almond trees.

Whether you opt for a drupe-producing almond tree or an ornamental flowering variety, it must be said that these trees are prone to their fair share of pests and diseases.

Habitat & Growing Conditions

Where almond trees are concerned, there are a few requirements which are rather hard-and-fast.

These trees are intolerant of waterlogged or poorly-drained soils; at the same time regular watering in spring and summer is necessary.

They grow in light, loose soils, and are averse to clay soils.

Hot, dry summers such as those of South Asia are ideal for almond trees.

While almond trees are hardy, any spring frost is usually extremely damaging to the buds.

P. dulcis is hardy to H5. Some cultivars are hardy to H6.

How To Grow Almond Trees

Almond trees are native to South Asia and the Mediterranean, and they grow best in the climates of those regions – which are not shared by the United Kingdom!

The best regions to grow almond trees in the UK are Southern England but not anywhere close to the coast, and East Anglia.

Spring frosts are the bane of almond trees whereas hottish, dry summers are a boon.

Sourcing Saplings

An almond sapling or young tree is not something that you can walk into your neighbourhood garden centre and buy.

You will need to look for specialist stone fruit nurseries online.

Be careful that you do not buy a dwarf flowering, non-fruit-bearing, almond tree (unless, of course, that is what you want).

Pollination

Except for a handful of self-fertile varieties, almond trees are not self-pollinating.

Therefore, if you grow P. dulcis you will need two or more trees, preferably three or four, of different cultivars for a reliable crop of almonds.

The trees should be spaced at 6-7m.

However, quite a few self-fertile varieties have been developed in Europe and California over the past decade or two and these are the best options for the home gardener.

The European ones include ‘Ingrid’, ‘Robijn’, ‘Sultane’, and ‘Princess’.

The American ones include ‘All-in-One’, ‘Independence’, ‘Shasta’, and ‘Garden Prince’.

The first three have been developed for America’s large-scale commercial growers. 

If you want to plant a single tree, ‘Robijn’ and ‘Ingrid’ are great choices for the UK.

Almond trees are seldom grown from seed for the home garden; they are usually bought as saplings or very young trees, and transplanted.

They bear almonds in two or three years from planting. Skilled green-fingers can propagate almond trees by budding and grafting, though.

Soil Requirements

The soil should be deeply laid, not overly-compacted, and it should be a sand-based loam with little or no clay.

A little organic humus or manure mixed in would be beneficial.

The soil should drain very well. Soil pH should be in the Slightly Acidic to Slightly Alkaline (6.1 to 7.8) range. 

Planting

The planting hole should be sufficiently deep and a little wider than deep and the site should enjoy full sun.

The April to May timeframe is most suitable for planting.

Plant the sapling with care, handling the root system very gently if at all.

Make sure that the roots are not matted or stuck and are spread out naturally.

Plant the sapling to the same level that it had been planted in the container, or at the nursery or wherever you had obtained it from.

It may prove helpful to mark the planting line in advance with marker or chalk.

Fill in the hole such that the soil is compressed but not loose nor overly-compacted.

Watering & Fertilising

As you begin to fill the hole, slowly water the roots with about a pail of water as you continue filling the hole.

After the hole is filled and the soil compressed, water it again with one more pail.

Even very wet soil, let alone waterlogged soil, is unsuitable for almond trees as it encourages fungal and bacterial diseases via the soil.

Frequent watering in spring and summer is a ‘must’ to ensure a profusion of blossoms and a bountiful crop.

“I always have an eye to the future when planting trees,” says Colin Skelly, RHS Master Horticulturist.

“Harvesting and storing rainwater is the sustainable option for growing almonds as the UK will become warmer (good for almond trees) but also drier (clearly bad for almonds and our water levels).”

Freshly-planted, young trees need 6-7cm of water daily be it from your hosepipe or the skies.

Mature trees need about the same amount of water every three days or so. Older, established trees need less water.

The tree’s water needs taper off in autumn and winter.

Every spring, fertilise the almond tree from trunk to drip-line – the edge of the canopy.

One of the best types of fertiliser for almond trees is a slow-release 12-12-6.

Harvesting Almond Trees 

The signal to begin harvesting is when the hulls start to split, exposing the shell.

For almost all varieties, this will happen in the August to September timeframe. 

How soon you harvest your almonds after the hulls start splitting depends to a great extent on the threat from insects and birds.

Ideally you should wait until about 75% of the drupes have split open but if you see or know that you will lose your crop (to insects and birds) you will have to harvest soon after you observe the drupes splitting open.

An almond tree is one of the easiest stone fruit trees to harvest. 

Lay plastic or canvas sheets around the tree, vigorously shake the trunk, and voila: garden-fresh almonds!

There will be some stubborn ones that refuse to be shaken off; to get these down on your sheet, simply use a pole to knock the branches or gently push the fruit off.

It is imperative that fresh almonds properly be dried before storing else mould can form on them.

The hulls must be removed (but not the shells).

The unshelled almonds should be spread out on a clean, dry surface, and where sunlight can fall on them to accelerate the drying process.

You may have to protect the almonds with mesh to prevent insects from getting at them.

When the almonds are thoroughly dry they can be stored in breathable bags.

However, one further step that is often taken is to put the almonds (in a bag) in the freezer for about ten days so that any worms and small insects are killed.

Pruning Almond Trees

Almond trees should be pruned from the very outset to maintain a desirable shape which, in turn, has an effect on the health of the tree and the production of almonds.

Almond trees should be pruned in November and December. Be wary of pruning them earlier or later.

Pruning fruit trees is a skilled horticultural task.

What is provided here is a mere guideline.

As a general rule, self-pollinating almond trees cultivated for home gardens need to be pruned to a lesser extent than the ‘usual’ varieties.

Like most fruit trees, almond trees are usually pruned into an open-centre vase form or shape.

This is a three-to-four year project – subsequent ‘maintenance pruning’ is, of course, desirable.

The objective is to reduce dense and wayward growth, favour the strongest limbs, and to increase air circulation above and around the tree and also increase the penetration of sunlight.

Air and sunlight are critical factors in preventing brown rot and other diseases.

In the first year (after planting), the leader is cut and four to five limbs, more or less equidistant and with an upward taper, are retained while almost all others are removed.

These will be the primary scaffold of the tree. Do not prune or shorten these scaffold limbs in the second or third year.

In the second year prune about 25% of the new growth while choosing a few more limbs for the secondary scaffold.

In following years continue to prune about 20% of the growth.

This should be maintenance pruning that removes dead and diseased branches, and problem branches.

Use pruning implements that are very sharp and sterilised – pruning wounds are a gateway for canker and other infections. 

Common Problems

Now for the bad part.

Almond trees are susceptible to their fair share of pests and diseases, which depend on the cultivar, the siting and climate, pruning, watering, and – of course – the presence of microbes.

To begin with, diseases include crown gall, peach leaf curl, and bacterial canker.

These diseases can be avoided by, respectively, employing correct and gentle planting technique, pruning to an open-centre vase form, and using sharp and sterilised pruning implements. 

Infrequently an almond tree may be afflicted by verticillium wilt, which is caused by a soil-borne fungus.

Unfortunately, this disease cannot be treated.

Another disease to be vigilant for is almond hull rot which may lead to a consequent infestation by navel orange worms.

The pests that may attack almond trees include aphids, scale insects, and red spider mite.

Thankfully, unlike verticillium wilt, these pests can readily be controlled.