If you would like to have a plant or pest identified, or a plant in your garden is diseased or dying, the Members' Advisory Service at Wisley may be able to help. A good sample helps the scientific staff in their work. Please follow these guidelines for sending samples.
Include as much information as possible, such as:
- the age, planting or sowing date
- the plant size and overall appearance since samples deteriorate in transit
- if diseased, the distribution of symptoms and when they were first seen
- notes on the planting site (e.g. in a greenhouse, a pot outside, or in open ground, in sheltered, windy, damp, dry, shady or sunny conditions, on heavy or sandy soil).
- details of watering are useful
- notes of any chemicals or fertilizers which have been applied and soil pH
Packing: Specimens should be placed individually in dry polythene bags, not "cling film", clearly labelled, and packed in a crush-proof box or padded envelope.
For disease diagnosis, wrap the specimen in dry absorbent paper such as kitchen towel, and then in a polythene bag.
For plant or pest identification, place directly in a polythene bag without wrapping. Do not wrap the specimen in wet paper.
Identification: Send a good-sized specimen with typical leaves, buds and if possible flowers, in good condition. Specimens should preferably be fresh, or carefully pressed with notes of the colours when fresh. Clear photographs can also be helpful. Please do not send more than five specimens at a time.
Some cultivars cannot be identified with certainty, particularly if they belong to large groups such as Rhododendron, Rosa, Dahlia and Camellia.
Please note, the RHS is not able to offer a root identification service.
Diseased material: Enclose samples of both healthy and unhealthy material, ideally one shoot or twig. If the plant is small, it is best to send the entire specimen. Place the root system with adhering soil inside a dry polythene bag secured at the base of the plant. Then place the whole specimen inside another bag.
Root disease: Leaf symptoms may be the result of root diseases. It is helpful to enclose root samples taken from four points equally spaced around the plant base. Include a range of root thicknesses and healthy and unhealthy samples. Do not wash soil from the roots. Include a cupful of soil from around the roots.
Turf: Samples should be at least 5 cm (2 in) square and 2.5 cm (1 in) thick taken from the junction of healthy and unhealthy areas.
Fungi: These should not be sent in a polythene bag, but wrapped in paper towel or newspaper. We only identify fungi which are harmful to plants. We do not comment on edibility.
Pests and other animal identifications: Where possible send live samples with their food plant. Place them in a dry polythene bag in a stout container. Soil-dwelling animals should be sent with some moist soil. Always give details of the circumstances in which the animal was found.
Please note: Sometimes pests and organisms that cause disease (pathogens) currently not established in the UK are detected as a result of samples sent to the RHS gardening advice service. Individuals and organizations, such as the RHS, are encouraged to report suspected new problems. Please be aware that when we suspect that a pest or pathogen may be new to Britain, we will report this to the Plant Health and Seeds Inspectorate, giving your contact details and possibly other information that you have given us so that the matter can be investigated by the appropriate authority.
For information on some non-native pests and diseases, some of which have already been found in Britain, click here.