Tag: Bourn Brook

Our contractors, Gary and Reg came back on 26 May 2026 with strimmers to cut back the emerging Himalayan Balsam plants and nettles along Bourn Brook.

They did a great job, (starting at 5:45 am to beat the worst of the heat) on a blisteringly hot day when the temperatures reached 35C in the shade….

Trumpington Farm company had also helped by using their mower a few days earlier, so this minimised the amount they had to do beside the meadow on the South bank. That, in turn meant that they had time to cut back some of the balsam and nettles in the wood on the north bank too. This will make it much easier for volunteers to deal with the remaining balsam plants..

In the wood, there are a few plants that will probably need to be plucked out by hand before they re-sprout . (This is because some were cut above the first node .. If they’re cut below the first node they’ll die). However the Himalayan Balsam plants are now much easier to see, so this should be a relatively simple and pleasant task.

On the south bank, its worth looking out for the occasional clump of stumpy Himalayan Balsam plants, emerging after the mowing..

We’re planning the first working party on Sunday 5 July. Do let us know if you’d like to help. (Please note that this is private land, so access is only by arrangement with Trumpington Farm Company)

If you would like to help by spending a few hours pulling Himalayan Balsam in this beautiful spot this summer, do signup here, or email us on info@camvalleyforum.uk

For some years, we’ve been trying to eradicate the Himalayan Balsam on the lower reaches of Bourn Brook. Although a pretty plant, it is highly invasive, so crowds out everything else. However, our problem has been that reeds and nettles have made it very hard to remove the Himalayan Balsam from the lower reaches of Bourn Brook, so its been quietly spreading… But we’ve now got help!

Pembrokeshire have a very useful advice leaflet, which includes the suggestion of using contractors to brush cut an area in early summer. They point out that this very substantially reduces the amount that needs to be hand pulled by volunteers, and “on a flood free site can get rid of most plants within a season”.

We’re excited about this idea, so earlier this year we raised the funds to engage contractors to help us by cutting back the reeds and nettles in advance of the main volunteer working parties.

We’d realised that we needed to start by cutting back the reeds, before the reed warblers arrive in mid April. The plan is that this will encourage them to make their nests a few hundred yards downstream, where they won’t be disturbed while we deal with the Balsam. They can then return next year (or the year after)

We started with a little preparation work in March 26, when volunteers cut back a bramble bush and piled up some fallen branches.

Trumpington Farm Company then kindly used their flail mower to cut what they could.

Then on March 24th 2026, our contractor (Gary, from MLP) worked hard for 2 days cutting back the more fiddly bits along the banks of the brook.

This created a delightfully clear meadow, all the way to the bank of the brook

By mid April we could see tiny Balsam plants plants starting to emerge, ahead of the nettles. It was very satisfying pulling them out by the handful!…

We will be repeating the cut on May 26th, aiming to once again, remove all the nettles, reeds and Himalayan Balsam plants on the south bank of the brook. This should substantially reduce the amount that we need to do by hand. It should also make it much easier to see new Himalayan Balsam plants when they start to emerge from remaining seeds.

To “finish” the job, we plan to run volunteer working parties roughly monthly from June – October to pull up any newly emerging Himalayan Balsam plants…. With your help and persistence, this should go a long way towards eradicating Himalayan Balsam from this beautiful spot, just upstream of Cambridge.

If you would like to help by spending a few hours pulling Himalayan Balsam in this beautiful spot this summer, do signup here, or email us on info@camvalleyforum.uk