PL. —Alliaria petiolataBotanical illustration — drop image
Alliaria petiolata

Wild Mustard

Spring
2a9bHardiness zone
Peak bloom windowZone 6b · frost-offset weeks
Winter
In bloom
Spring
Peak bloom
Summer
Not in bloom
Fall
Not in bloom
Peak bloom
In bloom
Background

Wild mustard is the field weed turned garden volunteer — it colonises disturbed ground in early spring. The flowers are nearly identical to cultivated mustard but the plant is looser and more branching. Where it appears, it can be harvested rather than weeded.

Not typically sown deliberately; more often it arrives on its own in vegetable gardens and field edges. Mustard is Allelopathic - meaning it hinders the growth of other plants near it, so yank it out when you see it.

Keep apart
Care guide
SunFull sun
WaterLow
SoilAverage, tolerates poor soils and disturbed ground
SpacingAllow to naturalise
Height18–48 inches
Zone2a – 9b
WinterAnnual / self-seeding weed.
Direct sowFrost hardy
Seasonal tasks
spring
cutHarvest yellow sprays as they appear in spring — useful early-season filler
watchRemove before seed sets if you don't want it spreading further
summer
watchBolting now — harvest seeds before pods split. Pull plants and clear bed to make room for summer vegetables.
Pests

Aphids

Aphididae
Symptoms

Clusters of small soft insects on new growth and flower buds.

Treatment

Knock off with a strong jet of water. Ladybirds and lacewings are natural predators. Insecticidal soap as last resort.

Flea Beetle

Alticini
Symptoms

Small round shot-holes scattered across leaves; tiny dark beetles that jump when disturbed. Heavy feeding stunts young plants.

Treatment

Use floating row covers on seedlings. Remove crop debris and weeds that harbor beetles. Apply kaolin clay or spinosad if damage is severe.