The RHS has teamed up with the Royal Holloway, University of London, for a new study that aims to identify the most important plant pests and diseases affecting their gardens.
The information they provide will form the basis of a list of the most damaging problems they face.
The UK's 27 million gardeners have until May to complete an online survey that will help scientists better understand the impact of plant pests and diseases on people's lives.
Information gathered by the survey will then be used to develop increasingly effective ways to control garden pests and diseases.
The survey can be found here.
The joint RHS/Royal Holloway study is described as a "deeper dive" into the pest and disease problems facing gardeners, problems that are less subject to the transitory impact of the weather, or of one-off occurrences, such as the discovery of a new pest or disease.
RHS head of plant health Dr Gerard Clover said: “The RHS is very fortunate to already have a bank of very rich information about the pest and disease problems gardeners face every year, but this new research is designed to drill down deeper to get to those core, persistent problems.
“When considering the question of what are the most ‘important’ pests and diseases to commercial horticulture, the focus is on the economic impact, but for gardeners the picture is more complicated.
“For domestic gardeners the scope is much broader, ranging from the impact on aesthetics, through the services plants provide (lawns for recreation and hedges for privacy), to the negative impact on the quality of fruit and vegetable crops. It is this very variety that we need to capture to get as full a picture as possible of the challenges facing gardeners.”