Himalayan Balsam
Himalayan Balsam is a major weed problem, especially on riverbanks and waste land, but can also invade gardens. It grows rapidly and spreads quickly, smothering other vegetation. Each plant can produce up to 800 seeds and can be dispersed to a distance of 7 metres The most effective way of control is to pull or cut the plant before it flowers.
Giant Hogweed
The sap of giant hogweed can cause burns. It contains furocoumarin, which makes skin extremely sensitive to sunlight (phytophotodermatitis).If the sap gets onto your skin and it’s then exposed to the sun, your skin can blister badly. Blistering can then recur over months and even years. This is known as phytotoxicity.
Hemlock
Hemlock is a poisonous plant which can be fatal if ingested. Removal should be considered where there are grazing animals or in areas which are used for leisure purposes and particularly where children may be playing.