Are We Planting the Wrong Trees for Britain’s Future?

“Planting a tree is an environmental decision that may outlive the person planting it.”

Planting trees is probably one of the few environmental actions almost everyone agrees is a good thing. Trees absorb carbon, provide shade, reduce summer temperatures, intercept rainfall, provide wildlife habitat and can make almost any street, garden or field more attractive.

But perhaps we need to ask a slightly more awkward question.

Are we planting the right trees?

A tree planted in Britain in 2026 may still be standing in 2100. It could experience a climate significantly different from the one in which we planted it.

That changes the question from:

“What tree grows well here?”

to:

“What tree will grow well here now, survive the next 20 difficult summers, cope with wet winters, resist future pests and still be useful to wildlife in 70 years?”

That is a much harder question.

A Tree Is a Very Long-Term Investment

When we plant bedding plants, vegetables or even many shrubs, choosing the wrong variety isn't necessarily disastrous. We can replace it next year.

Trees operate on a completely different timescale.

Plant an oak today and somebody who has not yet been born may eventually sit beneath it.

Plant a street tree badly and a future council could spend decades trying to keep it alive.

Plant thousands of genetically similar trees and an unfamiliar disease arriving in 30 years could turn what looked like an excellent planting programme into a very expensive mistake.

The RHS already advises gardeners to think about the conditions trees will experience when mature, rather than simply today's climate. Forest Research takes much the same approach in forestry: species must be matched not only to the site, but increasingly to its expected future climate.

That makes tree planting an unusually interesting form of environmental planning.

We are making decisions today on behalf of people living at the end of the century.

Britain Is Not Simply Becoming “Hotter”

This is where the problem becomes more complicated.

It is tempting to imagine climate change as Britain gradually acquiring the weather of southern France.

If that were all that happened, the solution might appear obvious: plant trees normally found farther south.

But Britain's emerging climate is likely to be much less convenient.

Forest Research describes a future characterised by hotter, drier summers alongside warmer, wetter winters, with increasing risks from drought, flooding, storms, wildfire, pests and diseases.

So the future tree may need to survive:

a saturated February
a surprisingly hard late frost in April
weeks with little rain in June
35°C or more during a July heatwave
an intense thunderstorm dropping a month's rain in hours
autumn arriving unusually late
and new insects or fungi able to survive Britain's increasingly mild winters.

That is very different from simply asking whether a tree likes warm weather.

Drought May Become One of the Biggest Problems

Trees need enormous quantities of water.

A mature tree has a vast root system that can explore a large volume of soil, which gives it considerable resilience.

A newly planted tree does not.

That means the tree-planting schemes we create to combat climate change can themselves be surprisingly vulnerable to climate change.

Forest Research identifies newly planted trees as particularly susceptible to drought, especially on exposed sites. Repeated drought can reduce growth, cause crown dieback and eventually kill trees.

There is also a lesson here for domestic gardeners.

We sometimes spend £50, £100 or considerably more buying a tree, put it in a hole, give it a watering can full of water and assume the job is finished.

It isn't.

The first few summers may determine the next 70 years.

A newly planted tree needs time to establish roots beyond its original root ball. If its first two summers happen to coincide with droughts, it may never become properly established.

Mulching can reduce evaporation and competition from grass. Deep watering at sensible intervals is generally much more useful than repeatedly wetting only the surface. RHS guidance also emphasises establishing young trees carefully and improving soil structure so that moisture can be retained without simply creating waterlogged ground.

So perhaps one of the least glamorous pieces of climate action is:

Plant fewer trees if necessary — but make sure the ones we plant survive.

Yet Too Much Water Could Be Just as Serious

Here is the apparent contradiction.

We may have drought problems in summer while simultaneously experiencing excessively wet winters.

Some soils could spend months saturated before drying hard during summer.

That is extremely difficult for certain trees.

Waterlogged soil contains less oxygen. Roots may remain close to the surface because deeper layers are unsuitable. Then summer arrives and the upper soil dries rapidly.

The tree that appeared to have had plenty of water all winter suddenly finds itself with a shallow root system during drought.

Forest Research specifically identifies these changing water-table conditions as a problem, while the RHS now provides guidance for gardens that alternate between winter waterlogging and summer dryness.

This is why there may never be a single “climate-change tree” that we should all start planting.

The answer depends on the soil.

The Right Tree Starts With the Ground, Not the Catalogue

Before deciding what looks attractive, I think we should increasingly ask some rather mundane questions.

What sort of soil do I actually have?

Does water sit on it after heavy winter rain?

Does it bake solid during summer?

Is the site exposed?

Which direction does the garden face?

How much space will this tree have when it is 40 years old?

What already grows successfully nearby?

A garden on chalk in Hertfordshire has completely different requirements from one on heavy clay, a windswept Scottish hillside or a wet garden in Wales.

Climate change does not remove those differences.

It amplifies them.

The old principle of “right tree, right place” therefore becomes something more like:

Right tree. Right place. Right purpose. Right future.

What About Our Native Trees?

This is where the debate becomes particularly interesting.

One argument says that if Britain's climate is changing, we should gradually move away from native trees and plant species from warmer parts of Europe.

Another says we should concentrate overwhelmingly on native species.

I don't think either extreme is particularly satisfactory.

Native trees matter enormously.

They have spent thousands of years developing relationships with Britain's fungi, insects, birds, mammals and other plants. Woodland is not simply a collection of trees. It is an ecosystem.

Oaks, for example, are extraordinarily important ecological structures supporting huge communities of insects, fungi, lichens and other wildlife. Losing such species cannot simply be compensated for by planting an ornamental tree that happens to grow faster.

If biodiversity is the main purpose of creating woodland, native species should therefore remain central to our thinking.

But native does not automatically mean invulnerable.

Climate conditions are moving.

Some species may increasingly struggle on particular sites, particularly where moisture becomes limiting.

And “Native” Is Not Quite as Simple as It Sounds

There is another fascinating complication: provenance.

Two trees can be the same species but have originated from populations growing hundreds of miles apart.

Over generations, populations develop adaptations to their local climate.

Forest Research therefore distinguishes between species selection and provenance selection — the geographical origin of the seed or planting material.

Imagine two populations of the same tree.

One has evolved in a cooler, wetter part of northern Europe.

Another has spent generations experiencing warmer, somewhat drier summers.

Genetically, both belong to the same species.

But they may respond differently when planted in southern England.

This has led to research into assisted migration, where planting material originating slightly farther south is considered for some forestry situations because it may be better adapted to future conditions.

But it is not a simple solution. Forest Research itself points out that provenance decisions remain uncertain and should differ according to whether the objective is timber production, conservation or something else.

In conservation woodland, retaining local or regional genetic adaptation and allowing natural regeneration may be extremely important.

Why Not Just Plant Mediterranean Trees?

At first sight it sounds logical.

Britain is getting hotter.

Olives grow somewhere hotter.

Plant olives.

Problem solved.

Except climate doesn't work like that.

A Mediterranean tree adapted to intense summer heat may still dislike months of British winter waterlogging.

It may tolerate 40°C but be damaged by an unexpected severe frost.

It may thrive in southern England yet struggle in Scotland.

And introduced trees may provide very different habitat from the species they replace.

The RHS specifically warns that trees from hotter climates can still be vulnerable to occasional British frost and that wholesale use of exotic trees would alter the character of our landscapes.

That doesn't mean Britain should never plant non-native trees.

Some may become extremely useful, particularly in towns and cities where soil, heat and drought conditions can already be unusually severe.

But:

“It comes from somewhere hotter” is not a tree-selection strategy.

Importing Trees Creates Another Risk: What Comes With Them?

There is another reason to be cautious about large-scale imports.

Trees sometimes arrive with passengers.

Fungi.

Bacteria.

Insects.

Eggs.

Larvae.

The UK has already experienced the consequences of introduced tree diseases, with ash dieback perhaps the most obvious example to the public.

Climate change can make matters worse. Warmer winters may allow previously unsuitable pests to survive, while drought-stressed trees can become more vulnerable to attack. Forest Research expects changing temperatures and moisture patterns to increase risks from several categories of tree pests and pathogens.

This gives ordinary gardeners one very practical action.

Ask where your tree came from.

The Woodland Trust strongly advocates trees that are UK sourced and grown, reducing the opportunity for pests and diseases to arrive in imported nursery stock. Crucially, UK-grown stock does not have to mean only native species: some non-native ornamental species can also be propagated domestically.

That might eventually become as normal a question at a garden centre as asking how tall a tree grows.

Diversity May Be Our Best Insurance Policy

One thing seems increasingly difficult to defend: planting huge areas with one species because it is cheap, fast-growing and convenient.

A monoculture creates efficiency.

It also creates vulnerability.

If every tree responds similarly to drought, disease or pests, one threat can affect the entire planting.

Mixed woodland behaves differently.

Forest Research recommends increased tree-species diversity as one way of spreading risk from drought, storms, wildfire, pests and pathogens. Different species fail under different circumstances, which means the woodland as a whole has a better chance of continuing to function.

It is rather like an investment portfolio.

Putting every penny into one apparently excellent company may produce spectacular results — until something goes wrong.

A mixture is less dependent on any single outcome.

That principle works surprisingly well even in a garden.

Instead of planting six identical ornamental trees along a boundary, perhaps a mixture would be more resilient.

Instead of creating a new woodland dominated overwhelmingly by one species, build ecological redundancy into it.

Diversity is nature's insurance policy.

Perhaps We Should Think About What the Tree Is For

Another mistake is treating all tree planting as though it had one objective.

Why are we planting?

For wildlife?

Native species and structural diversity may take priority.

For shade beside houses?

Future crown size, roots, summer shade and winter light matter.

Along streets?

Tolerance of drought, compacted soil, pollution and constrained rooting space becomes critical.

To reduce flooding?

Soil, catchment position and woodland structure may matter as much as individual species.

For timber?

Growth rate, timber quality, disease resistance and future commercial use become important.

Simply because we want a beautiful garden?

Perfectly reasonable — but mature size and future climate still deserve consideration.

There cannot therefore be one national list entitled:

“These are the trees Britain should plant.”

Context matters too much.

Some Trees Already Give Us Clues

This does not mean gardeners have no guidance.

The RHS already lists trees considered more tolerant of hot, dry conditions, including various whitebeams, hawthorns, plums, some maples, pines and several oak species. It separately identifies trees suited to waterlogged conditions.

But I would treat these as shortlists for investigation rather than shopping lists.

A drought-tolerant tree that eventually reaches 25 metres may still be a terrible choice for a six-metre garden.

A tree suited to a dry slope may be hopeless at the bottom of a heavy clay garden.

And a tree that survives perfectly may still contribute relatively little to local biodiversity.

Resilience must be considered alongside ecology, size, location and purpose.

Seven Things We Can Actually Do

This is where the subject becomes much more practical.

If you are planting a tree this autumn, I would suggest asking these questions.

1. Look at the site before choosing the species

Observe it after heavy rain and during dry weather.

Know whether your problem is primarily drought, poor drainage, exposure, shade or lack of space.

2. Think about the mature tree

Do not choose a 25-metre tree because the 1.2-metre specimen in the garden centre looks manageable.

Think decades ahead.

3. Keep native species in the mixture

Especially where biodiversity is important.

Trees are not simply carbon-storage devices; they are habitat.

4. Avoid putting everything into one species

If you have room for several trees, diversity gives you resilience.

5. Ask whether trees are UK sourced and grown

It is an easy contribution towards better biosecurity.

6. Help young trees through establishment

Mulch them.

Keep grass competition away from the immediate base.

Water properly during prolonged dry conditions.

Look after them particularly carefully during their first few growing seasons.

7. Look after the mature trees we already have

This may be the most overlooked point.

A 60-year-old healthy tree cannot instantly be replaced by planting ten saplings.

Old trees already provide shade, carbon storage, nesting sites, cavities, fungi, deadwood habitats and huge leaf areas.

Planting the future matters.

Keeping today's healthy mature trees alive matters just as much.

We Might Also Need to Let Nature Do Some of the Work

Not every future woodland needs to be completely designed by humans.

Natural regeneration allows successful local trees to reproduce, introducing genetic variation and allowing natural selection to operate.

Some seedlings will fail.

Others will cope.

Those survivors become part of the next generation.

Forest Research recognises that future woodland adaptation may involve both active management and natural ecological change, particularly in conservation woodland.

We may therefore need a mixture of approaches:

protect, regenerate, diversify, experiment and monitor.

Not simply plant.

The Most Important Tree Might Be the One That Survives

There is something slightly uncomfortable about tree planting as an environmental symbol.

It photographs wonderfully.

A group of people standing beside newly planted saplings looks like progress.

But perhaps we should return to that field 20 years later.

How many survived?

How many are healthy?

How much wildlife do they support?

Are they still suitable for the climate?

Did we plant enough diversity?

Did we introduce disease while importing them?

Did anyone look after them through their first drought?

Those questions matter far more than the number appearing on the original press release.

Conclusion: We Are Planting for People We Will Never Meet

Planting trees remains one of the most positive things we can do.

But climate change means we need to become considerably better at it.

The answer is not abandoning Britain's native trees.

Nor is it covering southern England with olive trees because summers are getting warmer.

It is understanding that resilience comes from matching trees to sites, protecting biodiversity, maintaining genetic diversity, improving biosecurity and accepting that different places need different solutions.

Some existing species will continue to thrive.

Some may become increasingly stressed.

Some non-native species may become valuable additions.

Some planting decisions will undoubtedly turn out to have been wrong.

That is inevitable when planning 50 or 100 years into an uncertain future.

But uncertainty is not an excuse to ignore the problem.

It is an argument for diversity.

When I look at a small sapling, it is easy to think about the tree I can see.

Perhaps we should instead imagine the tree it could become.

A child born in 2026 could sit beneath it as an elderly person in 2100.

The question is whether that tree will still be there.

Planting a tree is therefore more than an environmental gesture.

It is a vote of confidence in the future — and we should choose that tree rather carefully.