Glastonbury lies upon the steep sided hills and ridges of middle and upper lias which rise to the Tor Hill’s 520 feet above mean sea level.  It dominates the surrounding moors or levels of peat and alluvial clay which lie at an elevation of only 20 feet—below the level of the high tides of the Bristol Channel which is only 15 miles away.

The native trees on the levels are willow and alder.  The range of local plants, often now only found by neglected rhynes (drainage ditches), is decreasing as the water table drops with advances and modifications in levels farming.  The orchids common within a mile of Glastonbury 70 years ago have now gone but the comparatively rare soft hornwort has been seen in neglected ditches and there are still specimens of ragged robin, marsh woundwort, purple loose strife and meadow sweet close to the town.  Many of the meadows are covered with buttercups in the spring and the yellow flag is still common.

On the Avalon Hills are ash and oak with an occasional specimen of the Glastonbury thorn.  The hedgerows still retain some of the formerly common elm, together with hawthorn, blackthorn and hazel.  In places limestone downland flora survive—birdsfoot trefoil, self heal and hawkbits.  In the steep sided coombes are primroses whilst harts tongue and other fern are plentiful.  A number of cowslips and violets have survived the illegal picking which we believe is now decreasing as so many wild flower seeds are becoming commercially available.

The yellow vetch seen on the Tor in 1860 is now long gone.  It was noted as one of the species that are normally only found by the sea—relics of the time when tidal waters came over the levels. Many alien plants also came into the area on imported fleeces for the tanneries and are now to be found on the sites of their waste tips.