As you know, we have been working on combating giant hogweed from the Tees catchment for years... in order to eradicate the plant it takes consistent effort and commitment year on year. Since the COVID-19 pandemic, due to lockdown, we missed out on a year of spraying which unfortunately put us back.
Why is giant hogweed so hard to remove?
Longer Growing Season: Due to wet and warm winters, many plants, including giant hogweed are growing earlier in the year, and carrying on through to the winter. Due to a longer growing period, there are more plants, meaning more chance of spread.
Seeds, seeds and more seeds: Each giant hogweed plant produces between 20,000 and 50,000 seeds! Not only is that a lot of seeds, but they have 95% viability. Although the percentage of establishing reduces each year, the seeds can lay dormant in the soil for up to 15 years!
Hide and seek: Giant hogweed doesn't like to make it too easy for us to access to spray it! Giant hogweed seeds can spread through wind, in bird droppings, but also through flooding, such as our River Tees! As the seeds get washed up on the river banks they can easily establish in places that are hard to reach and find.
What are we currently doing about it?
Firstly, the work we do couldn't be possible without the help of our amazing local and corporate volunteers! We do various activities throughout the year in order to make controlling giant hogweed (and invasive species in general) easier!
Cutting Back - over the winter months, we go out along the river and cut back areas to create better access routes. As said above, giant hogweed tends to be in places that are hard to reach! So by going out and cutting back a few paths, it makes it easier for us to reach (especially with our knapsacks on!).
Bulb Planting - as giant hogweed dies back in the winter, it leaves the ground bare and more susceptible to erosion. This means the impact of flooding is worse, as well as negatively impacting the biodiversity. By going out and planting bulbs of native species such as daffodils, bluebells and snake's head fritillary, we are supporting the biodiversity, and lessening the impact of erosion caused by giant hogweed and other invasive plant species (such as Japanese knotweed and Himalayan balsam).
Wildflower sowing - One way in which we are trying to counteract the impact of giant hogweed, is through sowing wildflower seeds which has so far been successful! One area along the River Tees has previously been covered in giant hogweed. We have ploughed this site with the aim of pushing the giant hogweed seeds far enough down that they can't grow back up, we have then been sowing wildflower and grass seeds in this area to improve soil quality and increase biodiversity. So far, this has shown success with only a few giant hogweed plants returning!
Spraying - at present the best way that we get rid of giant hogweed is by spraying it with herbicide. The chemical we use is non harmful to animals and aquatic life (especially when working so close to the river). Due to the sheer volume of giant hogweed in our catchment, it would not be practical or safe for us or our volunteers to inject each individual plant or dig them out. In the future, there may be a possibility for biological control (as there has been for Japanese knotweed and Himalayan balsam in our catchment). However, at the moment this is not possible so we spray the giant hogweed.
Success...
There are definitely areas of our catchment that have seen great improvement in the presence of giant hogweed, with many sites only having a few small plants coming back each year.
However, as stated above, with the amount of seeds that giant hogweed can produce, it is crucial to carry on with our work.
Overall, our goal is to eradicate giant hogweed from the Tees catchment! But this is going to take time, and a consistent effort to control!
What do we need?
Resources - including knapsacks, chemical, PPE and staff to be able to undertake the work.
Volunteers - we couldn't do the work we do, without the help of our amazing volunteers! There is always work to be done that helps massively to keeping on top of giant hogweed!
Education - Giant hogweed is not a very nice plant (if you couldn't tell!) we need support in educating as many people as possible, to raise awareness about the dangers of giant hogweed and to minimise the negative impact of it as much as we can!