Heracleum sphondylium

RHS Plant Profile
hogweed

Other common names

cadweed, clogweed, cow parsnip, eltrot, giant parsnip, madnep, meadow parsnip, panasen y cawr

Plants for pollinators
Annual Biennial Herbaceous Perennial

A robust native biennial or short-lived perennial, frequently seen on roadside verges. Generally around 1m high it can reach 2m but is still much smaller than its infamous cousin giant hogweed. Stems are ridged and hollow, leaves hairy with broad, pinnate lobes. Off-white flowers in large umbels appear from midsummer to early autumn and attract a range of pollinators

Position

Full sun, Partial shade

Soil Types

Clay, Loam

Max Height

1.5-2.5 metres

Max Spread

0.1-0.5 metres

Size

Time to Maturity
2–5 years
Max Spread
0.1-0.5 metres
Max Height
1.5-2.5 metres

Growing Conditions

Clay Loam
Moisture
Moist but well–drained
pH
Acid or Alkaline or Neutral

Position

Full sun Partial shade
Aspect
East–facing or North–facing or South–facing or West–facing
Exposure
Exposed
Hardiness
H7

Colour & Scent

Season Stem Flower Foliage Fruit
Spring
Summer
Autumn
Winter

Botanical Details

Family
Apiaceae
Native to GB/Ireland
Yes
Foliage
Semi evergreen
Habit
Bushy
Potentially harmful
TOXIC to skin with sunlight. Wear gloves and other protective equipment when handling TOXIC to pets (dogs/poultry) with sunlight - see the HTA guide to potentially harmful plants for further information and useful contact numbers
Genus
Heracleum can be biennial or perennial herbs and include species such as giant hogweed, fennel, cow parsley and ground elder.
Name Status
Correct

How to Grow

Cultivation

Naturally grows in grassy places such as rough grazing, hedgerows and roadsides. Can be encouraged in wilder areas of the garden to support a wide range of pollinators including beetles, flies, hoverflies, bees and wasps. For information on its more problematic cousin see giant hogweed

Propagation

Propagate by seed

Suggested planting locations and garden types

  • Wildlife gardens
  • Wildflower meadow

Pruning

No pruning required, but deadheading will help prevent it self-seeding where not wanted

Pests

Generally pest-free

Diseases

Generally disease-free