This week at Penrose we have been tackiling the problems of invasive plants. Our focus this time was Himalayan balsam. It is a relative of the busy Lizzie, but reaches well over head height, and 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 as it goes.
So whats the Problem? Each plant can produce up to 800 seeds. These are dispersed widely as the ripe seedpods shoot their seeds up to 7m (22ft) away. Once established in the catchment of a river the seeds, which can remain viable for two years, are transported further afield by water.
How do we control it? Plants that out-compete other more desirable plants or simply invade half the garden are classed as weeds and require control. First, we consider whether this can be done using non-chemical means such as pulling or digging out, or suppressing with mulch. If this can't be achieved, we would consider using chemical methods. But as they are easy to pull from the ground due to shallow roots we decided to manually remove them from the site. And as you can see below even Noodles the dog leant us a paw.