What is the difference between a weed and a plant?

Plants which are intentionally grown in fields and gardens are called cultivated plants. All other plants which are not supposed to be there and grow unwanted, are called weeds. A weed is therefore a plant growing "in the wrong place".

A plant which you might cultivate in your garden can become a weed if it escapes to a farmer's field - don't leave the flower-heads to set seed.

Some weeds cause harm:-

• Some are parasitic on crops.
• Some are poisonous to cattle and sheep.
• Some are unpalatable or even cause taints in milk or meat.
• Some can cause a problems to animals, e.g. by getting into sheep's wool and be expensive to remove. Some thorns or spines can injure animals.
• Some interfere with farm machinery, getting tangled in the works.
• Some reduce the value of the crop (eg. deadly nightshade in peas, wild oats in cereals)
• Some are a host for pests and diseases.
• Some block drainage and irrigation channels.
• Some grow on non-agricultural land like roadsides and embankments and need cutting down.

Investigations:

• ? You could record garden "escapes" or oilseed rape plants along road verges,

J. Hewitson, Oundle