Millhoppers - Herts & Middx Butterfly Conservation

Millhoppers Pasture

Our Branch Reserve

This tranquil reserve is approx 3 acres (1.2 hectares) in size and consists of unimproved grassland surrounded by a variety of large trees and hedgerow. The site was acquired by the efforts of a few individuals from the adjacent village of Long Marston, a grant from Dacorum Borough Council and Butterfly Conservation. It was finally secured by Butterfly Conservation and dedicated to Gordon Beningfield in 1998 who sadly passed away just before the opening.

Habitat Management and Volunteering

Habitat management is vital to create and maintain a varied habitat in order to enhance the Lepidoptera (butterfly and moth) species on the reserve and promote other wildlife. To make this possible volunteers are needed for the monthly work parties.

Work parties (WPs) are held every month on the first Sunday of the month both winter and summer and new volunteers are welcome to come along

The WPs start at 9:50 am and finish around 2.30 pm (with a break for lunch) - Parking by the reserve is limited and so it is suggested that volunteers park in Wilstone Village and walk across the fields (see directions below).

If you would like to volunteer at any time and would like more information please contact the Millhoppers Wardens - email:

Grassland management
Regular work parties every month throughout the year are essential to keep the grass and unwanted scrub in check, and to mend fences etc. The mowing and raking of the meadows has generally encouraged more wildflowers to flourish each year, and there are already many more violets in flower in 2024 than in previous years.

To maintain the grassland and prevent it being overrun with blackthorn/prunus, volunteers have used tree-poppers to remove the unwanted saplings and their roots.

To reduce the growth of the more aggressive species within the grassland (e.g. nettles, hogweed and thistle) and provide a suitable habitat for wildflowers to grow the grassland needs to be cut mechanically each spring and autumn, or better still grazed with sheep or cattle. In the autumn of 2018, the repairs to the perimeter fence were completed and in November 2018 some Herdwick sheep were introduced to graze the reserve for the winter for the first time in recent times.

The encroaching blackthorn/prunushedge line has been pushed back in various places and some conservation hedge-laying was completed in the 2018/2019 winter and has since continued. Slowly the hard work is paying off!

The wildlife pond and chalk bank
The reserve historically contained a marshy area alongside a small stream. For a number of years there has been no year-long water in the stream and a number of water-specific species were no longer present. However, the streambed and marsh area require yearly cutting. Despite the wardens working with various organisations in order to try and re-establish regular water flow through the reserve no progress was made so an alternative was planned!

In the autumn of 2021, after careful research a lined pond was dug and a chalk bank was created. Research involved working out the best shape/depth etc. for the wildlife pond and the result was a pond with one deep section and very shallow, wide edges. Some pebbles were put around the edge of the pond in places, to give a more natural look and increase the pond habitat, and native pond plants were introduced, including some Marsh Marigold plants which used to grow so well at Millhoppers when the site was wetter. The pond has been buzzing with activity since early spring and has attracted numerous species, including damselfly and dragonfly, frogs, hoverflies and many types of bugs and beetles. Now that the stream at Millhoppers only flows in the winter months, it seemed right to have a water body on the site all year round, to provide a place for insects and amphibians to breed and all this wildlife makes the pond a great attraction to anyone visiting the site. A fence has been erected around the pond with the help of a group of our own and Chiltern Society volunteers, to make the site safe, and also to keep out the sheep which may well be grazing at Millhoppers in the spring and autumn months in future years.

A hibernaculum has been constructed close to the pond to provide sheltered places for amphibians to hibernate. The pond is doing very well and is certainly adding to the biodiversity of the site. On several occasions toads have been found lurking in damp places and damselflies and dragonflies were seen gliding, and breeding around the reserve in 2023. The chalk bank was also constructed with the soil which was dug out to make the pond and chalk sourced from local excavation work on the Wendover Arm of the canal. The bank has been seeded with Bird’s-foot Trefoil, Rock Rose and Kidney Vetch which are the food plants of the Common Blue, Brown Argus and Small Blue butterflies respectively, and Common Knapweed and Greater Knapweed have been seeded at the bottom of the bank to provide a good nectar source for pollinators. This bank is important, as generally the soil at Millhoppers is quite fertile and smaller wildflowers tend to be out-competed by course grasses and Hogweed which can dominate. The chalk will be an ideal medium for the more delicate wildflowers which are such a good food source for butterflies and other pollinators, and we are hoping the new Kidney Vetch plants will attract the Small Blue butterfly to the site. The shape of the bank will allow insects to enjoy a sunny, south facing slope, but will provide more shady places when the weather is very hot.

Millhoppers chalk bank Millhoppers wildlife pond

The Chalk bank still needs some attention, as some of the chalk has subsided leaving a few bare patches on its side and this has prevented us from planting the plug plants of Kidney vetch and Rock Rose which we have grown from seed.

Help needed: we are now looking for a new source of chalk to make a thicker chalk layer before any more planting takes place. So, if anyone knows a good source of not too expensive chalk, we’d be very grateful if you could please let us know.

Woodland Management
In 2023 many of the trees in the small wood at the bottom of the reserve (mainly Elder) were dead and gradually falling over. They were impeding the growth of new trees, so it was decided to pull them down and use the wood to make a splendid dead hedge along the side of the river, on the north-eastern side of the reserve.

Following the theme of increasing the biodiversity at Millhoppers, it was proposed to plant 26 native trees – the choice of native trees was guided by the high number of Lepidoptera and Invertebrates they support. Some trees were purchased, and some came from free tree planting schemes; including a Woodland Trust tree package of 15 trees (5 Crab Apple, 5 Rowan and 5 Hazel), free donations of a seven year old Oak, a Field Maple and a Silver Birch. Also purchased was an Alder, an Alder Buckthorn (to attract Brimstone), four more Hazel (to establish some Hazel coppices), a Wych Elm (to attract the White-letter Hairstreak), and a Small-leafed Lime. Preparation of the planting areas and the planting sessions took place in the winter of 2023/24. All the trees were carefully positioned on the periphery of the site or in the wooded area, to avoid shading the meadow.

Tree planting

Butterfly and moth recording
In 2023 three new volunteers were found to walk the butterfly transect at Millhoppers, one of whom is 13 years old. It’s really good to know that someone from the younger generation is keen to be involved with the reserve on a regular basis and is so competent at spotting and identifying butterflies. In 2023 two new butterfly species were seen on the site – the Small Heath and the Silver-washed Fritillary.

Essex Skipper

Speckled Wood

Painted Lady

Small Skipper

Small Heath


Large Skipper


Small Tortoiseshell

Orange Tip

Meadow Brown


Large White


Small Copper

Small White

Marbled White

Holly Blue

Green-veined White

Silver-washed Fritillary

Brown Argus


Red Admiral

Common Blue

Meanwhile Chris Hilling continues to monitor the moths with his light trap on a regular basis and has now recorded over 370 species. Different surveying methods are also tried such as sugaring and pheromone lures which attracted Old Lady moths and Orange-tailed Clearwing moths respectively, amongst others. Chris also records other wildlife at the site, and in the summer of 2023, he found a bright yellow and pink leafhopper, a species unknown to him, but with help from the Royal Entomological Society, it was identified as the nationally scarce Tremulicerus fulgidus, which feeds on Black Poplar.

The Millhoppers Wardens would like to thank their wonderful volunteers who have been extremely supportive with all of the projects over the years and have given us extra days’ help to move the chalk and to help to construct the fence, they would like to express their greatful thanks to all who help on the reserve.

Millhoppers Pasture History

The strange name possibly originates from a stream-crossing to an old mill long since untraceable. Others contend that it derives from mill-stones laid to enable people to cross the stream. The entire area then was much wetter. Millhoppers is a rare example of a remnant of ancient countryside encircled by arable land. It contains a large section of unimproved grassland. Some of the hedges are thought to date back to Tudor times. It possesses a pond fed by a stream and a public footpath provides access on one side.

The site has a large stand of blackthorn scrub which provides good cover for birds and mammals. There are 16 black poplar trees in the hedgerow. This a nationally rare tree, but not uncommon locally.

The Black Poplars
The Black Poplars at Millhoppers

The first years

At the beginning, the main efforts were directed to cutting and raking off grass. In addition, the vigorous blackthorn scrub and large banks of nettles had to be contained.

In the summer of 2001, a new bridge was built across the stream. It is a good, secure structure, which can safely carry grass cutting machinery. Cattle were introduced to the reserve in 2003, and it was planned that they would graze both in the autumn and the spring. These animals were provided and cared for by a local farmer but unfortunately in 2006 grazing was no longer possible.

This meant that more cutting and raking had to be undertaken, whilst new animals were found to graze the reserve.

In 2007, an 'Awards for All' grant was obtained, and a new Reserve interpretation board was designed and leaflets printed At the beginning our main efforts were directed to cutting and raking off grass. In addition the vigorous blackthorn scrub and large banks of nettles have to be contained.

In 2009, John Noakes stood down as the first Reserve Manager, and Jez Perkins took over. We are most grateful to them and Margaret Noakes for their dedication and hard work in managing Millhoppers since the Branch acquired it.

The cows crossing the new bridge
The cows crossing the bridge soon after they arrived in 2003
© photo: John & Margaret Noakes

Directions and location of reserve

Unfortunately there is limited parking space by the reserve and it is suggested that if visiting, you park in Wilstone Village and walk across the fields.

When walking from Wilstone, follow the public footpath alongside the children's playground next to the Village Hall. Cross the canal via the footbridge and head across the fields towards Long Marston. Go straight on without turning left or right until you reach Watery Lane (aka Astrope Lane). Across the road there is a choice of 3 footpaths - the right-hand one leads immediately to the reserve entrance, which is through a metal gate on the left. Total distance: half a mile. (Grid reference for Village Hall is SP903142 [Landranger Map 165] or postcode HP23 4PE).

For more detail click on map >> >>


Public transport

Wilstone is served by local buses.

Site access and Safety

Access is via footpath gates and stiles. Path bridges cross the stream and these may be slippery in the wet. The Public Footpaths run along the edges of the reserve, and access onto it is on a permissive basis.

When cattle and sheep graze the site, dogs must be kept on leads.

Please clean up after your dog.

Most ticks are little more than an irritation, but a few can transmit Lyme disease, a rare and potentially serious illness which is treatable with antibiotics if diagnosed early. It is therefore important to be informed and take some simple precautions.