The Science of Gardening

Episode image for The Science of Gardening

Episode 32 of 27, Gardeners' World, 2010/2011

Duration: 1 hour

Carol Klein invites us into her garden to unearth the science beneath the muck and magic of gardening.

Carol has been a passionate gardener for over 30 years and, like many gardeners, she's fascinated by what's going on at a deeper level when it comes to her plants. So, Carol turns her beloved garden into a living laboratory and plays host to scientific experts who help her to explore, analyse and observe her soil, compost, seeds, weather, leaves, and flowers.

Carol asks the questions to which many gardeners want answers: Why don't my seeds germinate? How does compost work? What is photosynthesis and why is it important? What happens when we prune a plant? How do insects see flowers? And how can I work out which plants should go where in my garden?

Carol shows that by understanding the science behind gardening, we can all become better gardeners and grow more beautiful and more bountiful gardens.

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  • THE SCIENCE OF SEED STORAGE

    THE SCIENCE OF SEED STORAGE

    If you like the idea of growing your own plants for free, then collecting and storing the seed from plants in your garden is a must. Waiting for the seed to ripen properly and then collecting on a dry day is the start of the process. If you then carefully and thoroughly dry the seed, using a suitable desiccant like silica gel or dried rice grains, many seeds of garden plants can then be stored at very low temperatures and last for years.

    BBC gardening guide on seed collecting
  • EXPERT FEATURED – Dr Robin Probert

    Dr Robin Probert is an international expert in seed collection and storage at the World renowned Millennium Seed Bank – the biggest seed storage facility in the world. He’s also a passionate gardener and helped Carol to hone her self-taught seed collecting and storage skills with expert scientific advice.

    Kew Millennium Seed Bank conservation project
  • UNDERSTANDING YOUR SOIL

    UNDERSTANDING YOUR SOIL

    An understanding of the ratio of your soil’s main ingredients will help you discover which soil type you have and unearth the answers to which types of plants will grow best in your garden. Some plants will only thrive in light sandy soils, others need heavy clay soils to grow well, others prefer a fine silty or loamy soil with lots of organic matter.

    Try this simple experiment –

    Take a large clear container that has a tight lid, such as a jam or preserving jar.
    Fill it 1/2 full with water.
    Add your garden soil until almost full
    Close the lid tightly
    Shake the container well for a full minute
    Leave the container somewhere completely still and undisturbed

    Once the soil has completely settled it will have separated into distinct layers (this can take as little as a few minutes for the heavy sand and silt layers, and up to a week for all of the tiny clay particles to fully settle!)

    The bottom layer is the heaviest constituent – sand
    The next layer up is silt
    The next layer up will consist of clay particles: the higher up the container the smaller the particles
    Organic matter such as compost and humus will be floating right at the top of the container at the surface

    These layers will give you a clear picture of the proportions of sand, silt, clay and vital organic matter in your garden soil – and help to discover what main soil type you have.

    BBC gardening guide on soil testing
  • EXPERT FEATURED – Prof. Keith Goulding

    Professor Keith Goulding is the 2009 & 2010 President of the British Society of Soil Science.

    British Society of Soil Science
  • THE AMAZING STRUCTURE OF LEAVES

    THE AMAZING STRUCTURE OF LEAVES

    Plant leaves are incredibly diverse, complex and intricate structures. When using a high powered electron microscope to explore them fascinating and amazing structures hidden to the naked eye are revealed particularly on the upper and lower surfaces of the leaf.

    Internally, however, the basic structure of the leaves of many of the flowering plants we grow in our gardens are very similar.

    More detailed information on leaf structure at Wikipedia
  • EXPERT FEATURED – Kim Findlay

    Kim Findlay is head of bio-imaging at the John Innes Centre and specialises in using an electron microscope. Beams of electrons are used in an electron microscope to create 3-D images of a specimen. This enables higher magnifications than a light microscope, and allows us to see much smaller objects in incredible detail.

    More incredible electron microscope images of plants
  • THE WEATHER IN YOUR GARDEN

    THE WEATHER IN YOUR GARDEN

    Weather and climate are slightly different things. Weather can be described as the state of the atmosphere at a given time and place, with respect to variables such as temperature, moisture, wind speed, and atmospheric pressure. It can also refer to the effects of adverse or destructive atmospheric conditions, such as high winds or heavy rain. But climate refers to the meteorological conditions that prevail in a particular place over time.

    So weather can change from one moment to the next, but climate changes over longer periods of time and is cumulative.

    However even across an area the size of an average back garden, the climate can be extremely varied, and by understanding the different micro-climates that exist, you can have greater success with the plants that you grow in different locations, and find the right plant for the right place.

    BBC Plant Finder
  • LEAFY HORMONES - Plant Growth Regulators

    LEAFY HORMONES - Plant Growth Regulators

    Plants have hormones similar to animals; they control growth and development and are vital to reactions to stimuli during its life cycle.

    Unlike animals, plants lack glands that produce and secrete these hormones. They are produced within the cells of plants in various key areas of growth and development like shoot and root tips for example.

    They are more commonly known as Plant Growth Regulators, and there are 5 main groups:

    Auxins
    Cytokinins
    Abscisic acid
    Gibberellins
    Ethylene

    They often work together in tiny concentrations to promote and influence the growth, development, and specialization of cells and tissues.

    More about plant hormones
  • EXPERT FEATURED – Dr Hilary Rogers

    Dr Hilary Rogers works in the School of Biosciences at Cardiff University and her work specialises in understanding the molecular mechanisms controlling flower development and plant cell division.

    More about Dr Hilary Rogers and her research interests
  • ‘FLOWERS’ and ‘INFLORESCENCES’

    ‘FLOWERS’ and ‘INFLORESCENCES’

    Throughout the 2010 series of Gardeners’ World, Carol has been exploring a different botanical plant family each week. Historically, botanists used floral characteristics to determine similarities and differences between groups and species of plants. Often what appears to be one flower, can be a complex arrangement of numerous individual flowers all carefully structured to form an ‘inflorescence’. Recognising and identifying the shapes and forms of the many types of inflorescence is a science in itself!

    There’s more information on inflorescences at Wikipedia
  • EXPERT FEATURED – Dr Jeff Ollerton

    Dr Jeff Ollerton is a senior lecturer in ecology and plant pollinator relationships at the University of Northampton.

    For a more in depth look at his research group's interests

Credits

Presenter
Carol Klein
Director
Andy Vernon
Producer
Andy Vernon
Executive Producer
Gill Tierney

Broadcasts

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