Greater Water Parsnip Introduced to Thorpe Marshes Nature Reserve

Published: 24th June, 2020
Flowering Greater Water Parsnip – Jeremy Halls

On the 23rd of June 2020, the Water, Mills and Marshes team planted 46 young Greater Water Parsnips (Sium latifolium) along the dykes in Norfolk Wildlife Trust’s Thorpe Marshes Nature Reserve. This was the final part of a School Conservation in Action project to expand the distribution of the Greater Water Parsnip within the Broads National Park.

Tuesday was a landmark event being the first time, since records began, that this plant can be found at this site. Hopefully, these perennial plants will, in the coming weeks, become firmly established and flourish. At nearly two meters tall when fully grown, with cloudlike umbels of bright white flowers appearing in July to August they are sure to be an iconic species for visitors to spot.


The 46 plants waiting to be planted out.

The decision to introduce Greater Water Parsnips to Thorpe Marshes Nature Reserve came about in a desire to actively involve school students in the conservation of an endangered species. The population of Greater Water Parsnips in the U.K. has declined rapidly in the last 40 years due to loss of suitably managed habitat and the drainage of wetlands. Indeed, they are an endangered wetland plant in this country and on the UK Biodiversity Action Plan. The Broads National Park with its marshes, dykes and expanses of fen provides the perfect habitat for these plants and they already occur at a number of locations. But suitable sites, like Thorpe Marshes Nature Reserve, had (until Tuesday) no current population. So, with permission from Natural England, Norfolk Wildlife Trust, Crown Point Estate and the RSPB, it was decided school students could introduce the Greater Water Parsnip to this site.


Picture of project class of 2019
Collecting seeds at Cantley Marshes, September 2019 .

Four schools signed up to the project, a total of 150 Year 5 students. The initial plan back in 2018 was for the students to collect the seeds, grow them in school and then take the young plants to Thorpe Marshes and plant them along the dykes. Sadly, these plans had to be abandoned due to the outbreak of Coronavirus. Of the four schools in the project, three were able to plant their seeds prior to lockdown and only Acle Primary School managed to get theirs to germinate. Having seen the excitement and interest displayed by the students when introducing the project to them (I’ve never been bombarded with so many questions in an hour before!) as well as when they were sowing their seeds, it feels particularly cruel that they were unable to see them germinate and grow and then plant them. Hopefully, we will be able to run something similar in the future and the students will be able to follow the process through to completion.


The Greater Water Parsnips hardening up in the neighbour’s fountain.

Luckily for the Greater Water Parsnip, the Water, Mills and Marshes team planted the remainder of the seeds at home during Lockdown. Many of these successfully germinated and grew into strong plants spending May and June hardening up in a kind neighbour’s plastic fountain!

Tuesday morning found us, along with Jeremy Halls the advising ecologist, lugging pot loads of plants around Thorpe Marshes Nature Reserve and digging the plants into their new homes. It definitely didn’t feel right without groups of excited students giving us a hand! As way of compensation we have been keeping them all updated with regular photos of the plants as they grew and were established in their new home.



Thorpe Marshes Nature Reserve
Planting Out

The 46 plants have been placed along the dykes close to the reserve’s footpaths so that visitors can see them and most importantly, in areas with limited grazing from cattle who find them very tasty! In preparation for their arrival the edges of the dykes were mown the previous week to reduce competition from other plants and so give the parsnips a good shot at getting established.

Now our job is to monitor how they get on and hope all 46 of the Greater Water Parsnips thrive in their new home at Thorpe Marshes Nature Reserve.

Read the Norfolk Wildlife Trust article here.

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