Documents: Special Interest: Horticultural Therapy:

RHS warns against buying problem plants online
by RHS
June 13, 2021

The Royal Horticultural Society (RHS) is reminding gardeners to only buy online plants and seeds from reputable British garden centres or nurseries to minimise the risk of introducing new pests and diseases.

The number of UK gardeners has swollen by three million over the last year to 30 million. The charity believes that this new demand coupled with the popularity of online plant sales could see people unwittingly taking risks with their web purchases, introducing new plant health issues.

Pests and diseases imported from abroad have the potential to spread widely, causing damage to gardens, crops and landscapes. One such example is ash dieback, a disease which is predicted to kill around 80% of the UK’s ash trees at a cost of £15 billion.

Plants and seeds for sale from reputable British companies may have originated from overseas but will have been imported following the government’s strict plant health regulations meaning the risk of inadvertently introducing new pests and diseases is significantly reduced, so too the risk of them containing invasive or banned plant material.

However, plants bought from online platforms and market places may not provide details of a plant’s origin nor be subject to the necessary plant health checks.

One particular concern, not currently thought to be in the UK, is Xylella fastidiosa, a plant bacterium known to infect over 500 different species of plant. The pathogen originates from Central America and was introduced into Europe in 2013 where it has caused severe losses in Italian and Spanish olive and almond groves. If it was to come into the UK, it would have devastating consequences for the UK’s gardens and horticultural industry.

Many plants such as orchids and snowdrops are also subject to strict conditions for sale owing to their endangered status while others are deemed so invasive that their sale is banned in Britain. This includes Water fern, Parrot’s feather, Floating pennywort, and Water primrose.

To mitigate the risk the RHS is calling on gardeners to:

1. Ensure the online shop that you buy plant material from is based in Great Britain and is a reputable garden centre or nursery by checking the address and contact details of the company on the website.

2. If the origin of the plant or seeds you are buying is not clear, don’t buy them.

3. Don’t plant up seeds or other material that arrived unsolicited via the post, even as a gift, unless you are sure that it is from a reputable British supplier or you know the origin.

4. If you want to order plant material from a reputable overseas garden centre or nursery, you need to check that what you want to buy is allowed into Britain and what the requirements are for importation.

The RHS has more information on the importing and exporting of plants by individuals on its website:

Lisa Ward, Principal Plant Health Scientist at the RHS, says: “The boom in gardening has seen online sales rocket over the last year, enabling many to find solace among their plants. However, gardeners need to be made aware of the issues around buying material that has not been subject to the right checks and approvals. A plant may be readily available or perhaps cheaper to buy online but the potential for that plant to cause problems on your own and surrounding plots isn’t a risk worth taking.”

The warning comes as part of The International Year of Plant Health (IYPH) which has been extended into 2021 and is run by The Food and Agriculture Organisation (FAO) with the International Plant Protection Convention (IPPC) Secretariat.

The RHS science team are currently conducting research into more than 17 garden pests and diseases. This work will move to a new state of the art facility, RHS Hilltop, within RHS Garden Wisley this year and will open to the public on June 24th. For more information visit:

  • New Eden
  • Kids Garden
  • Plant a Row Grow a Row