Lem Brook Himalayan Balsam carnage!

We’ve just finished a pilot project with the Worcestershire Wildlife Trust in the Wyre Forest which seeks to completely wipe out Himalayan Balsam (HB) along the length of an entire stream.

Why – it’s pretty!

There’s loads of HB growing along streams and rivers right across the UK and it does indeed look very impressive. It was introduced to the UK in 1839 as a garden plant. Problem is, it’s too successful at spreading and out- competes native plants resulting in large areas where nothing else grows. It also spreads very quickly, particularly along watercourses. HB produces 5-6000 viable seeds per square metre!

In the winter the HB all dies back leaving large areas of bank free of vegetation. When there is a flood or high water a lot of soil gets washed into the stream or river clogging the gravels on the bed. Fish and insects then find it difficult to breed and survive in these conditions.

Problems in the Wyre

The Dowles Brook is the largest stream running through the Wyre. We know that sediment is a problem and one of the reasons it fails its Water Framework Directive status.

By carrying out extensive surveys of the area (on foot!), we found the worst HB problems were on the Lem which is a small tributary of the Dowles Brook.

So our plan is to blitz the Lem Brook and see if HB can be completely eradicated.

What we’ve done

The challenge is big. We’ve contacted 28 landowners and carried out a detailed survey of 6km of brook.

Out of them 16 landowners are directly involved and 3km of bankside have been completely cleared by hand.

We know that HB seeds stay viable for up to 2 years so we will be returning next year and beyond. We will also continue to survey any re- growth and monitor any improvements in water quality.

Some folk think hand pulling can’t achieve full eradication. We’re carrying this project out on a single small catchment to see if it can!