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

After growing cress and learning what plants need to grow, this clip will emphasise the importance of water. Using images of different plants, children may be challenged to guess how much water they need. A discussion may involve asking the children why they think some plants need more water than others.