Home Gardening news RHS bans 9 overseas plants from shows to stop Xylella

RHS bans 9 overseas plants from shows to stop Xylella

At risk... hebes
At risk... hebes

Drastic action to stop destructive bacteria reaching the UK

Nine plants grown overseas have been banned from all of the Royal Horticultural Society’s (RHS) shows in 2018, beginning with the Chelsea Flower Show, in a bid to stop a devastating form of bacteria from reaching the UK.

If you haven’t heard of Xylella fastidiosa, it’s because it hasn’t reached our shores yet. Being imported through trade ornamental plants is seen as the most likely route into the country.

Show exhibitors have been told overseas high-risk Xylella specimens of hebe, rosemary, oleander, olives, lavender, polygala, coffee, Spanish broom and Prunus willed be barred. Only plants grown from seed in the UK or that have been here for at least a year are exempt.

The bacterium has the potential to cause disease in a wide range of woody garden and native favourites.

Symptoms of infection include leaf scorch, wilt, dieback, and death – all easily confused with frost damage and drought, or other diseases. Xylella is spread by insects which feed on infected plants.

Spread of Xylella infection in Europe

It is native to the Americas and was absent from Europe but in 2013, Xylella started to infect, and kill, olive trees in Italy. It has since been found in France, Germany, Spain, and the Balearic Islands, affecting oleander, polygala, numerous ornamental plants, cherry trees, and almonds.

Nurseries, designers, and the landscaping industry are concerned that all imported stock may have to be screened to prevent Xylella, with many implications on price, sourcing, selection, etc.

The arrival of Xylella in the UK would have a huge negative impact on the entire industry, right down to us gardeners, so it’s in everyone’s interests to be aware.

Chief Plant Health Officer’s plea

Professor Nicola Spence, Chief Plant Health Officer for the UK, has issued a plea to the horticultural industry to be vigilant.

She said: “The impact on the sector were Xylella to arrive in the UK would be significant – commercially and environmentally important trees and plants would be at risk, while restrictions would include a ban on movement of host plants from premises within 10km of an outbreak for at least five years.

“In the UK, we are carrying out inspections of all consignments of host plants of Xylella imported from outside the EU and have an inland surveillance programme, targeted at host plants being grown and traded. We are also disseminating publicity material, including information on the high-risk plants and guidance on sourcing plants.”

This is a complex and changing issue – more information and updates are available on https://www.gov.uk/guidance/protecting-plant-health-topical-issues. Also, the RHS has a very useful page for gardeners on new pests and diseases, with further links if you need them – https://www.rhs.org.uk/science/plant-health-in-gardens/protect-your-garden/new-pd-risks.


  1. I read about the plane loads of stuff brought into the UK to build exhibits at Chelsea which, of course, is organised by an organisation whose goal is, supposedly, to promote British gardening. I think back just a few years to an RHS promotion of Valentines (I think it was) bouquets made up of imported flowers when UK growers could produce bouquets using British grown flowers. And I ask myself “What does the RHS actually do?” It now bans certain imported flowers from Chelsea et al. Why, I wonder, cannot it merely insist that ALL plants are UK grown? A display of plants that require a tropical climate to perform at all is merely that – a display. People “Ooh” and “Aah” from behind the barricades. Gardens are best appreciated from within, not without. And the plants used should be those which our army of UK gardeners stand a chance of growing successfully in our climate. Perhaps my question should be “What is the point of the RHS?”

  2. […] Most people think you can’t, however you can, but there are restrictions and a moral argument about bringing plant diseases into the country (see my post on The RHS’s and Dame Helen Mirren’s campaign here), especially with Xylella on the rampage in Europe – for more about that, click here. […]

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