Plant health advice

Plant health is now one of the most important aspects of growing and distributing plants in the UK.

There are many serious pathogens already here and others under close scrutiny in Europe. All Collection Holders, Plant Guardians and plant enthusiasts should be aware of health issues affecting the plants in your care and be aware of simple steps to avoid inadvertently spreading diseases or pests.

Plant Biosecurity

Incoming plants are the single most frequent way in which pests and diseases are introduced into a garden. Always take sensible precautions to reduce the risk of inadvertently introducing pests and diseases on brought-in plants. For anyone taking part in one of our plant exchanges or bringing in new plants to their gardens or collections please read the guidelines on quarantine and plant monitoring below. 

Detailed guidance on Biosecurity from the National Trust is available here through the PlantNetwork website.

If you are involved with bringing plants in and out of the country, we have advice in the page on legislation

Quarantine area

  • Keep new plants in a separate area from plants already in your garden or greenhouse.
  • Make a record of the plants when you receive them; to include where they came from, date, size and condition on arrival.

Plant monitoring

  • Try to hold plants in a separate area for as long as possible: at least two weeks is suggested for small, container grown plants; six weeks is advised for plants of special conservation significance or for larger material.
  • For herbaceous plants make a visual check by knocking out plants from their pots to look for any pests or diseases
  • Re-pot into your own compost and keep in quarantine for at least two weeks.
  • Check the plants carefully and monitor them weekly or daily if possible.

Plant and compost waste

  • Bag and dispose of all used compost (from brought-in plants), do not spread on your garden or in open compost bins, where any potential pest or disease could proliferate.

Plant Health

The main resource for plant health is the UK Plant Health Information Portal, maintained by DEFRA.

The UK Plant Health Risk Register records and rates risks from pests to UK crops, trees, gardens and ecosystems. A search function is available by plant name or pest name. 

The RHS advice pages of their website have hundreds of searchable advice sheets, which covers a wide range of garden plant health problems.

Tree Health

For news and resources on tree pests and diseases, see the Forest Research website. Anyone growing trees is encouraged to use the TreeAlert system to report suspect pests and diseases within the UK.

If you would like to be more involved, in monitoring and reporting tree health concerns, see the Observatree website.

Notifiable pests and diseases

Plants showing symptoms of the certain pests and diseases should be reported to the Animal and Plant Health Agency (APHA).

A full list of notifiable pests and diseases including factsheets can be found here.

The RHS website also provides information on emerging pest and diseases that gardeners should be vigilant for.

eg: plant genus, common name, county, collection holder name.