Control Himalayan Balsam without harming grass
Selective control of Himalayan Balsam (without harming grass)
Himalayan Balsam, (Impatiens glandulifera), is native to the Western Himalayas and since its introduction in 1839 it has spread throughout the British Isles.
It is the tallest annual plant found in the British Isles, growing to more than 2-3 m in height. Each plant can produce 800 seeds, which are released explosively from the seed pods, travelling distances of up to 7 m. The seeds, which are also transported by water, can remain viable for up to 2 years. Hence it has rapidly colonised river banks, excluding native species by competition and forcing some areas to introduce eradication policies.
The Impatiens family is widely known by the cultivated species, often known as Bizzie Lizzies. This is their big brother !
Stems are pinky red, hollow, sappy, brittle and jointed. Branches arise from the stem joints. Leaves are lanceolate with serrated edges, stalked, shiny, dark green with a reddish midrib.
eaves can be 150mm long and are opposite or in whorls of three.
Flowers are purplish pink to pale pink or rarely white. They are shaped like a policeman’s helmet and carried on long stalks in June - October.
Seeds 4 -7 mm turning from white to dark brown or black and carried up to 16 per pod.
Treat Himalayan Balsam with Depitox for selective control
Use Depitox 3.3 litres per hectare rate (165ml/10Litres)
Ideally spray the weeds are at or before the rosette stage. If controlled completely, the weed will only take 2 to 3 years to eliminate. It is only an annual and shallow rooting, but an incredibly explosive seeder, allowing it to spread rapidly (Busy Lizzie cousin), therefore, must aim to stop it flowering/seeding each year.