Thlaspi arvense

RHS Plant Profile
field pennycress

Other common names

boor's mustard, dish mustard, French weed, Mithridate mustard, pennycress, treaclewort, wild cress, stinkweed

Annual Biennial

An annual with an upright habit that grows between 30–60 cm in height. It has smooth, branching stems and spear-shaped leaves that emit a mild garlic-like scent when crushed. It produces clusters of small, white, unscented flowers arranged on upright stems from May to July, followed by distinctive flat, round seed pods resembling old pennies

Position

Full sun, Partial shade

Soil Types

Chalk, Clay, Loam, Sand

Size

Time to Maturity
1 year

Growing Conditions

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

Position

Full sun Partial shade
Aspect
South–facing or West–facing
Exposure
Exposed or Sheltered
Hardiness
H5

Colour & Scent

Fragrance Foliage
Season Stem Flower Foliage Fruit
Spring
Summer
Autumn
Winter

Botanical Details

Family
Brassicaceae
Native to GB/Ireland
Yes
Foliage
Deciduous
Habit
Clump forming
Genus
Name Status
Correct

How to Grow

Cultivation

Thrives in disturbed soils like farmland, roadsides, and field margins. Prefers full sun and nutrient-rich, well-drained loam but tolerates sandy or clay soils. See Creating wildflower meadows for further advice

Propagation

Propagate by seed, self seeds freely

Suggested planting locations and garden types

  • Cottage and informal garden
  • Wildflower meadow
  • Wildlife gardens

Pruning

No pruning required

Pests

Generally pest-free

Diseases

generally disease-free