An explanation of the conditions needed for plant growth, with particular emphasis on water requirements. A greenhouse manager, Julian, tells us they have thousands of plants growing, including wheat, barley and maize. They help the plants to grow by providing light, water, soil and warm temperatures. Julian explains how some plants, such as water hyacinths and rice, need a lot of water and even have their roots standing in water. Cereals, potatoes and maize might need water once a day, whereas cacti only need water every two to three days.

First broadcast:
8 October 2007

This clip can introduce an investigation on how water affects the growth rate of different plants. Different groups of children may investigate different plants to find out the best amount of water for effective growth. This will consolidate the importance of fair testing to find out how much water different plants need. Children may also use research information to write growing guides for different plants, specifying the amount of water they need.