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RHS: Maintain Plant Health (3)Taught by Hilary Thomas

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‘You can trust the RHS to teach you everything you possibly need to know’ ~ Jamie Butterworth

  • Signs of pests and diseases

  • Environmentally-friendly biological controls

  • Impact of weeds

  • Safe use of herbicides


This module will enable candidates to make informed decisions about how best to tackle common risks to plant health, such as pests, and viral and bacterial diseases. Candidates will cover the symptoms of prevalent diseases, and consider the best way to treat these problems without harming the environment or upsetting the natural balances in their garden. Additionally, this module will look at weeds - the reasons for their success, and the best ways to minimise their impact.

The Curriculum

  • 1. Maintaining Plant Health

    This lesson tackles external factors affecting plant health. This will include the impact of pests and weeds, and the impact of plant diseases and disorders. You will then be given pointers as to how to make informed decisions about the best solutions for each of these problems.

  • 2. Biological Control

    Here you will learn about the different biological and chemical methods of controlling pests. This will include the potential benefits of predators and parasites. You will be given an overall view of the different benefits of each method, as well as advice on how to minimise the risks associated with each solution.

  • 3. Herbicides

    In this lesson you will be introduced to the different types of herbicide. You will also be informed of the possible impact on the environment of each herbicide, and consequently how to maintain the natural balances of your garden.

  • 4. Problems Caused by Weeds

    This lesson doesn’t just cover the problems weeds create, and their subsequent impact on your garden. Instead it will teach you about the reasons for weeds success and the different classifications of weed, leaving you better informed to choose how best to tackle weed problems.

  • 5. Pests that Cause Problems in the Garden and Glasshouse

    You will focus primarily on the problems caused by pests. This will include a review of the different impacts and that different pests can have. You will then learn about the different methods of control for common pests.

  • 6. Fungal Diseases

    Here you will learn first about factors increasing the risk of infection by a fungal disease, and so how best to reduce the risk of infection. You will be introduced to common fungi (for instance the honey fungus and grey mould), and be shown the signs they present, and the possible solutions.

  • 7. Bacterial and Viral Diseases

    In this lesson you will study the varied methods of control for bacterial and viral diseases, as well as how to look for signs of some of the most common diseases. You will then be shown the signs and perils of: frost damage; temperature damage; and water logging.

Meet your expert tutor

Hilary Thomas was Head of the School of Garden Design at the highly regarded Capel Manor College where she taught both Horticulture and Garden and Planting Design for over 20 years. Her students won ...read more

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