Research
Pest Problems at RHS Wisley
The Royal Horticultural Society (RHS) is the UK's leading garden charity, with the aim of enriching everyone's lives through plants, making the UK a greener and more beautiful place. RHS Wisley, located in Surrey, is a historic garden that has been trialling plants for over 100 years. The RHS carry out experiments, known as plant trials, to evaluate a plant's performance, characteristics, or suitability for a specific purpose, such as for garden use, commercial crops, or ornamental markets. These trials involve growing a variety of plants or applying different treatments under controlled conditions to compare them and assess qualities such as growth, yield, and disease resistance.
In 2021, RHS Wisley moved their plant trials to an area at the heart of Wisley, known as the Trials Garden. This is where new plants and gardening methods are being assessed and compared year round to help develop more suitable and sustainable gardening practices.
One of the largest threats these trial plants face is pests, which can cause significant damage to and even destroy the plants, as shown by the leeching of colour on the petals in the image below, caused by insects known as thrips:
Traditional methods to deal with these pests usually involved manually counting them one-by-one, and then either physically removing them from the system, or spraying the pests with harmful chemical pesticides. These methods are time-consuming, environmentally damaging, and ineffective for many trials as some pests are so small they cannot be easily seen.
The RHS are committed to ending pesticide use in their gardens and are no longer spraying chemicals to combat pests. A new approach using biological control, such as nematodes and garden predators, has replaced traditional means of pest control. Research into 'companion planting' methods is another pest control method the RHS is currently pursuing, allowing the RHS to move into a more sustainable future.
Pest control trials require constant monitoring of a very large number of pests, which is a very difficult task for just a handful of people. To test if the planting/sustainability methods have been effective in these trials, we therefore need a way for pests in plants to be automatically detected.
This task has lead to researchers at the Wisley trials garden to team up with astrophysicists at Lancaster University, forming the RHS Wisley Bug Watch team! Our aim is to apply similar object detection techniques from astrophysics to create a machine learning algorithm that can automatically detect pests in plants and differentiate between the different insects.
...and this is where you come in!
Your task will be to examine images of the plants in the RHS Wisley trial gardens taken to see what pests and other insects you can spot. You will mark the location of any insects you find on the images, and this data will be used to develop a machine learning algorithm that can automatically identify insects in various types of plants.
Your contribution will not only create an automated way to detect these insects but will also help us understand the effectiveness of planting and growing methods (e.g. companion planting), which will aid in developing more sustainable and eco-friendly pest control methods.
The RHS has dozens of plant trials currently ongoing, with some having required the help of the RHS Wisley Bug Watch community! Currently active and completed plant trials involved in RHS Wisley Bug Watch are given below:
Current Trials
Sweet Pea Trial
need section describing sweet pea trial, including its set up, aims and the pests
Completed Trials
Gladioli/Alyssum Companion Planting Trial (2025)###
A trial currently being assessed in the trials garden is the companion planting of alyssum with gladioli (as seen in the image above); alyssum is planted in rows parallel to the gladioli plants, with the aim to draw pests away from the gladioli, as well as to attract predator insects that eat the pests.
This trial was the first RHS trial that employed the help of Zooniverse volunteers. 400+ volunteers contributed to the 20,000+ classifications of 1,500+ images of alyssum plants, helping to identify thrips, pirate bugs and other insects! The data collected during this trial will be used to create an automated way to detect these insects through machine learning methods, alongside allowing us to study the effectiveness of companion planting of alyssum with gladioli, helping to develop more sustainable and environmentally friendly pest control methods.
Plants involved in the trial
Gladioli is a genus of plants in the iris family. Gladioli grow from round-shaped corms, which are short, bulbous underground plant stems. Gladioli have sword-like leaves and upright flower spikes (contributing to the name of the plant, with the translation of 'gladiolus' being 'little sword'!) that bear funnel-shaped blooms that open outwards from the base, with different gladioli species having many different colours. Gladiolus thrips are attracted to and feed off of the gladioli plant.
Alyssum is a genus of compact and low growing plants that have long, slender green leaves and small, white, honey scented flowers that grow in clusters. Alyssum attracts pollenating insects, and is being used in this trial to attract thrips and other insects away from Gladioli plants.
