Summer heat made UK plants more vulnerable to fungi and pests, RHS warns

Plants damaged by extreme temperatures are most at risk of disease, Royal Horticultural Society says

Summer’s prolonged droughts and extreme heat have made plants more susceptible to problems such as fungi and insects this coming autumn, the Royal Horticultural Society has warned.

Plants stressed or damaged by the heat are most at risk of disease, but the charity’s experts say gardeners should also look out for specific plants that are typically more vulnerable such as tomatoes.

Tomato growers may be noticing more blight than other years and the RHS advises those worried to “pick off green tomatoes and leave them to ripen on a windowsill”.

The changing seasons are also expected to lead to more mildew. “Mildew can look bad but it’s nothing to panic about for gardeners,” said the RHS. “Gardeners can pick off the worst affected leaves and ensure plants are watered but not saturated.”

The RHS also warned gardeners to look out for an increase in honey fungi and glasshouse thrips – a type of garden pest – in the coming months.

Honey fungus (Armillaria mellea) is described by the RHS as the “most destructive fungal disease in the UK” and is expected to cause greater devastation than usual this autumn after summer’s exceptionally hot weather left plants more vulnerable. It can be deadly to plants, spreading underground to attack and kill the roots, before causing the dead wood to decay.

With no chemical able to control the spread, the RHS advises gardeners to improve plant resilience by maintaining good plant health, making sure plants grow “in suitable conditions” and watering young plants less often but more thoroughly.

The UK’s record-breaking summer temperatures have also given rise to the glasshouse thrip, a tiny insect that can thrive in greenhouses.

Generally found in hot and dry conditions, this species of thrip has increasingly been able to survive in the south of the UK as the climate heats up.

Although the insects often do not cause noticeable damage, a garden infestation can cause mottling or spread plant viruses. Symptoms to look out for include silvery discoloured leaves, marked with small brown-red spots caused by the insects’ excrement. Worried gardeners should note that thrips can be controlled by natural garden predators, including the bug Orius laevigatus.

Sara Redstone, the biosecurity lead at RHS, said: “One of the best ways to maintain healthy plants year round is to let nature help in your garden. Gardens can play an important role in climate resilience and gardeners can maximise this by selecting and planting species which tolerate weather extremes in their local conditions.

“These resilient plants will be less stressed by the increasingly frequent harsh conditions we expect to see under climate change, and therefore stand a better chance of surviving disease.”

Yasmeen Louis

The GuardianTramp

Related Content

Article image
‘Superhero’ moss can save communities from flooding, say scientists
Sphagnum moss found to drastically slow down rainwater runoff in Peak District ‘outdoor laboratory’ study

Waseem Mohamed

30, Sep, 2022 @1:00 PM

Article image
Hosepipe bans, water butts and beavers: what can we do to combat drought in Britain?
Parts of UK are preparing for emergency water measures despite country getting more annual rainfall than rest of Europe

Helena Horton and Sascha Pare

06, Aug, 2022 @7:00 AM

Article image
Why growing fungi at home is beginning to mushroom
Home fungus growers can boost soil quality in small gardens and cultivate exotic varieties using coffee grounds and online kits

Helena Horton Environment reporter

26, Nov, 2022 @8:00 AM

Article image
Warmer UK weather adding to spread of fruit tree diseases
Royal Horticultural Society links spread of orchard infections to heatwave with trees still at risk

Helena Horton Environment reporter

03, Mar, 2023 @12:06 PM

Article image
RHS asks gardeners to find interesting ‘weeds’ that may be rare plants
People urged to submit specimens to an app as private gardens may be fresh source of scientific discovery

Helena Horton Environment reporter

04, Feb, 2023 @7:00 AM

Article image
Cop27: crucial climate talks more fragile than ever after year of turmoil
With war in Ukraine and a cost of living crisis, the global picture is much changed since last year’s conference

Fiona Harvey Environment editor

05, Nov, 2022 @12:00 PM

Article image
National Trust tells of bats in distress and water features drying up in heat
Charity says extreme conditions a ‘watershed moment’ and it is planning for long-term hot weather

Jessica Murray Midlands correspondent

10, Aug, 2022 @5:00 AM

Article image
Weather patterns may lead to flooding in February, Met Office warns
Government embarks on campaign to raise awareness over weather threat as England remains in drought

Helena Horton Environment reporter

07, Nov, 2022 @1:22 PM

Article image
More than 400 weather stations beat heat records in 2021
Maximiliano Herrera, watcher of extreme weather, says last year likely to be in top five or six hottest in history

Bibi van der Zee

07, Jan, 2022 @11:03 AM

Article image
What happens when drought is declared by the UK government?
With drought declared in parts of England and other areas at pre-drought stage, we look at some key questions

Tom Levitt

12, Aug, 2022 @1:08 PM