Collard Hill, in pursuit of the Large Blue
near Street, SomersetRoute details and mapDownload as a print friendly PDF
In 2002 Collard Hill was opened by the National Trust on behalf of the Large Blue Partnership as a great place for the public to come and see this rare and fascinating butterfly. Having disappeared from the UK in the late 1970s, the large blue is flourishing here and even at busy weekends, you’ll find plenty of quiet spots in which you can get a good glimpse of them.
- Bus stop
Start: National Trust car park, grid ref: ST488340
From the car park near the youth hostel, head east, following the blue-topped posts, which we put up to direct visitors to Collard Hill during the large blue season.
The butterflies usually fly within a three-week period between early June and July, though the timing of this depends on the weather. Individuals live for just four or five days. Numbers tend to be best during the third week of June: earlier in hot summers, a bit later if it is cooler.
Follow the path through woodland glades and out into rough grassland. Look out here for marbled white and ringlet butterflies, plus several types of orchid.
Cross over a (blind) summit crossroads with great care. Go to the opposite, south-east sector of the crossroads, heading towards the Scots pine trees, and a National Trust stile and interpretation board.
Head right, towards and through the scattered pine trees. The blue-topped post route guides you through some key large blue areas, but feel free to explore.
Enjoy the views from Collard Hill towards the Polden Hills, the Somerset Levels, and Glastonbury Tor. Collard Hill is a great picnicking spot. On a hot summer day though it can be exposed and stifling, so bring plenty of water, youll need it. Outside the butterfly season, the slopes are grazed by ponies and cattle to keep vegetation short. This gives the right conditions for the type of red ant, whose grubs the large blue caterpillars eat.
Start climbing the lower slopes of Collard Hill then continue walking straight ahead, traversing halfway up the hillside. Large blues fly all along here. They tend to use the lower slopes in windy weather, but never fly north of the new fence that runs along the crest of the slope. In the distance is Butleigh Monument on Windmill Hill.
Other resident butterflies include marbled white, meadow brown, small heath, brown Argus and, in August, a few brown hairstreak (pictured here). Only two other blues occur on Collard Hill: the common blue and holly blue both are smaller than the large blue, and they fly earlier in the season. Black spots on the large blues forewings distinguish it from all other blue butterflies. The common blue is brighter and the holly blue has plain azure-blue wing upper sides without black borders. 90 per cent of the blue butterflies you see here are large blues.
A favoured area for the large blue is the East Bank, a grassy open area east of the track that runs diagonally down the slope. Explore and leave via a path cutting through the scrub at the bottom of the slope.
In summer, you may come across colourful pyramidal, common-spotted or fragrant orchids. Lucky visitors may even see a bee orchid one of the most striking plants at Collard Hill. The large blue loves to feed on nectar from wild thyme flowers. They also lay their eggs in the thyme flower buds.
Turn right and follow the bottom of the slope back to point five and return to the start of the walk.
End: National Trust car park, grid ref: ST488340
- Trail: Walking
- Grade: Easy
- Distance: 1.5 miles (2.5km)
- Time: 30 minutes
- OS Map: Explorer 141; Landranger 182
Steep to moderate grassy and chalky slopes, which are hard and bumpy when dry, and slippery when wet. Cross the busy B3151 crossroads with particular care.
- How to get here:
By bus: Bus 377 from Yeovil and Street to Collard Hill (alight Marshalls Elm crossroads)
By car: 1 mile (1.6km) south of Street and to the east of the B3151
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