Knebworth Woods

Also within

Hertfordshire County

Condition (Natural England)

Habitats

Coppiced woodland

Description

Area,120.8 hectares 298.5 ac Description This woodland site is of a type nationally rare, but well represented in Hertfordshire. It is a most important woodland in the north of the county lying on poorly drained acidic soils derived from underlying clay with flints. It is almost all ancient in origin and is ecologically diverse with rides, ponds and small areas of both acidic and neutral grassland. Oak Quercus robur and Oak/ hornbeam Quercus robur / Carpinus betulus are the dominant woodland types with some mixed deciduous type characteristic of south east England. In the main part of the wood coppiced hornbeam is over mature and ground flora is suppressed. Other areas such as Watery Grove are currently being coppiced resulting in diversification with ground ivy Glechoma hederacea, bugle Ajuga reptans and primrose Primula vulgaris. The mixed deciduous wood contains ash Fraxinus excelsior, downy birch Betula pubescens and aspen Populus tremula together with oak. A heathy element in the rides produces locally rare species green ribbed sedge Carex binervis and heath milkwort Polygala serpyllifolia. Small areas of the site have been felled and replanted but are currently under management to promote some regeneration of semi-natural woodland. The ponds contain two plant species rare in Hertfordshire, water voilet Hottonia palustris and fine leaved water dropwort Oenanthe aquatica. The woodland is known as a site rich in fungi and bryophytes and breeding nightingales are indicative of the diverse bird community. Burleigh Meadow, acidic grassland, supports some heathland flora including petty whin Genista anglica and Dyers Greenweed Genista tinctoria in drier areas and lousewort Pedicularis sylvatica where wetter, all three species being county rarities. The neutral grassland meadow is still the best Hertfordshire site for green winged orchid Anacamptis morio despite some limited damage in the past. The south east boundary of the meadow is formed by a line of old coppiced hornbeam.

Species mentioned

Insects to look out for

These moths, butterflies and beetles are known to feed on plants recorded at this site, and carry a notable UK conservation status — but a host-plant being present doesn't mean the insect has actually been recorded here. Treat this as "worth watching for," not a confirmed sighting.

Host-plant data: Cook et al. (2025), Traits data for the butterflies and macro-moths of Great Britain and Ireland, 2024, UK Centre for Ecology & Hydrology / Butterfly Conservation; and Padovani et al. (2020), Database of Insects and their Food Plants (DBIF), UK Centre for Ecology & Hydrology (both Open Government Licence). Contains data supplied by UK Centre for Ecology & Hydrology.