Small, hard, sour; they are the kind of apple that should you happen to take a bite, you might well choose not to bother with a second.

While picking out their tiny seeds requires the patience of a saint; they are barely the size of a pencil tip.

With little to do with the tart, bitter fruit other than make crab apple jelly, some might well not bother.

Yet with incredible dedication, steady hands and laser focus, a team from Royal Botanic Garden Edinburgh has spent countless hours first tracking down elusive native wild crab apple trees – ones that have not been crossed with other varieties - gathering up sack loads of their fruit before gently removing thousands of individual tiny seeds.

Eventually the Edinburgh-based Scottish Plant Recovery project picked a staggering 25,000 individual seeds from the cores, every one of which then had to be thoroughly checked, recorded and stored.

Tiny but potentially powerful, each seed holds the precious key to the securing the future of one of Scotland’s lesser spotted and quite possibly least appreciated fruit trees.

A combination of factors has led to truly wild crab apple (Malus sylvestris) becoming one of the rarest trees in Scotland; precise details are known for only around 300. 

A feature of the landscape since the last Ice Age, their scattered and isolated locations and risk of cross-pollination with non-native varieties, left them facing bleak future.

A stash of 4407 of the miniscule seeds retrieved in autumn are now chilling out in a laboratory fridge in temperatures intended to replicate a typical Scottish winter.

They will remain in peaceful slumber until spring, when they will be planted in barely a tablespoon of soil to, hopefully, grow.

The Herald: Crab apple trees have been a feature of the landscape since the last Ice AgeCrab apple trees have been a feature of the landscape since the last Ice Age (Image: RBGE)

All this painstaking effort is intended to eventually lead to thousands of new native crab apple saplings. With careful attention paid to their genetic credentials to ensure the right mix, they will be planted in selected rural spots.

The scale of the project, attention to detail and painfully finicky elements of retrieving the seeds is astonishing.

But, says project leader Max Coleman, it is crucial if the native crab apple, with its terrifically tart fruit, is to survive relentless pressure -  much of which comes from its sweeter, tastier cousins.

“We are giving them a helping hand, a bit of a lift,” he says. “And it’s all looking quite hopeful.

“We collected the seeds recently, they’ll grow for two seasons and we’ll be looking at planting them towards the end of our three year project.

“Right now, the chances are good that the ones that are sown will grow.”

Generally, apple trees would seem to have little problem flourishing in Scotland: for years, the Clyde Valley, for example, was the nation’s fruit basket, with fertile soil that provided rich apple pickings.

But the cultivated domestic apples’ roots are in Asia – spread along the ancient Silk Road trading route from China to Turkey to arrive in Europe, crossing naturally with wild apple species on the way.

The ease with which they can interbreed with Scottish crab apple trees combined with the native trees’ sparse numbers has seen numbers ‘crumble’.

While the native apple’s ‘super genes’ which enabled it to survive thousands of years have been passed to their cultivated cousins, boosting their ability to cope with local conditions and making them even more resilient.

“When the cultivated apple first arrived on our shores it did not pose a threat to native apples,” explains Max.


The Herald: Native crab apples are tiny compared to some other cultivated applesNative crab apples are tiny compared to some other cultivated apples (Image: RBGE)

“Isolated wild apples in a landscape where cultivated trees and ‘pippins’ – feral trees grown from discarded apples – are common, will tend to produce hybrid offspring.

“We have now reached a point, backed by genetic evidence, where many ‘wild’ apples are in fact hybrids or feral trees.

“The numerical advantage of cultivated apples means that they are likely to continue to dilute the gene pool of the wild apple unless we take action to protect the native species.”

He adds: “Sourcing seeds from surviving native trees with a low likelihood of having hybrid offspring allows us to raise a new generation from various locations that will contain the necessary genetic diversity to be able to form viable new populations.”

The project identified 16 crab apple trees fitting criteria for a native version: thorny shoots emerging from the branches is one sign, small, hairless leaves and stalks, and tiny apples are another.

“Someone then sat with a knife, chopping open and removing the seeds – 25,000 of them,” he added. “And we have 4407 seeds ready to be sown.


The Herald: Woodland Trust Scotland has planted a new crab apple orchardWoodland Trust Scotland has planted a new crab apple orchard (Image: WTML Woodland Trust Scotland)

“They need to go through a period of cold storage: in nature they would have sat on the ground exposed to frost, but in our propagating facilities they are put in a fridge, kept damp and we’ll bring them out to germinate in spring.”

Genetic testing will confirm their ‘wild’ credentials and saplings will only be planted when confirmed to be genetically correct.

While the remaining seeds from the 25,000 retrieved will be dried and placed in cold storage where they may remain for decades, to be wakened if needed.

“It’s like an insurance policy,” he adds.

Work to save the wild crab apple is part of a wider RBGE project supported by the Nature Restoration Fund, which aims to revive the fortunes of ten threatened native Scottish plants: five trees, four flowers and one fern.

Launched earlier this year, it is already preparing to translocate 250 wych elm seedlings grown in its labs.

Wych elm has been severely impacted by the fungal pathogen Dutch elm disease, leaving numbers so thinly spread that natural cross-pollination between trees is highly unlikely.

The young trees should begin reproducing within 20 years creating a natural spread of new trees.

While efforts are also underway elsewhere to revive the fortunes of the native crab apple, with its delicate pink and white flowers and long association with folklore – it is traditionally linked to love, marriage and fertility.

The Herald: Native crab apples are dwarfed by ‘Belle de Boskoop’ apples Native crab apples are dwarfed by ‘Belle de Boskoop’ apples (Image: RBGE)

Woodland Trust Scotland staff and volunteers recently gathered at its Glen Finglas Estate in the Trossachs for the climax of a five-year hunt to track down wild crab apples, and to plant a seed stand of 59 trees.

Twigs cut from pure wild apple trees found in Galloway, Argyll and Ross-shire were grafted to root stock to create the new orchard, described as a “genetic refuge for crab apple trees”.

The new trees will provide a source of seeds which can then be used to produce trees for future woodland creation schemes.

The work at Loch Venachar has been carried out in partnership with forestry consultant Rick Worrell. He said: “Most apple trees people see in the countryside are not truly native.

The Herald: A new crab apple orchard is being created by the Woodland Trust ScotlandA new crab apple orchard is being created by the Woodland Trust Scotland (Image: WTML - Woodland Trust)

“They are often the result of cores from eating-apples being discarded. Apples love to hybridise so there is a wide spectrum of trees out there with varying proportions of wild and domestic genes.” 
The wild trees found by the Trust were tested at RBGE to ensure they are, indeed, native trees.

While the new orchard is in an area where there are no domestic or hybrid apple trees nearby to avoid the chance of cross-pollination. 
A further 29 trees will be added to the site next year.

The Trust’s volunteering development officer Matilda Scharsach said: “If we hadn’t taken steps to create this new orchard preserving the wildest native stock, there was a real prospect of losing them forever.”