Treacle mustard
Erysimum cheiranthoides · Brassicaceae
The gardener's calendar
Ideal time to plant treacle mustard: set it out when the soil is neither frozen nor waterlogged, and water generously as it establishes.
ID card
- Family
- Brassicaceae
- Plant type
- Annual or biennial herb
- Flowering
- Spring to summer (April-July)
- Adult height
- 30-60 cm
- Flower color
- Golden yellow
- Hardiness
- Good, down to -10°C
- Origin
- Central and southern Europe
- Growth
- Fast
Care
Sunlight
Wallflower cabbage prefers a sunny location, with at least 6 hours of direct sunlight daily. In warm regions, light afternoon shade can prevent early wilting. This plant also tolerates partially shaded spots, but flowering will be less abundant there.
Watering
Keep the soil regularly moist but not waterlogged, especially during initial growth and flowering. Once established, the plant tolerates some dryness. Reduce watering in winter for biennial plants. Water at the base to prevent foliage diseases.
Soil and planting
Prefer well-drained, fairly light to moderately fertile soil. Wallflower cabbage accepts sandy, chalky or neutral soils. Enrich the bed with some well-decomposed compost before planting. Avoid compacted soils or soil too rich in nitrogen, which promotes foliage at the expense of flowers.
Fertilizing
A moderate application of balanced fertilizer in early spring is generally sufficient. Limit nitrogen inputs to avoid excessive foliage development. Excessive fertilization can slow flowering and weaken the plant.
Pruning and maintenance
Pinch young stems to encourage dense branching and a compact shape. Regularly remove spent flowers to extend the flowering period. Light pruning in late summer can rejuvenate biennial plants and stimulate a second flush of blooms.
Diseases and pests
Like all Brassicaceae, this plant can be affected by white rust and whiteflies. Ensure good foliage aeration and avoid stagnant moisture. In case of infestation, intervene quickly with suitable preventive treatments or consult a specialist.
Did you know?
Wallflower cabbage gets its common name from its resemblance to wallflower (Cheiranthus), with which it shares the same plant family. However, it is a plant long naturalized in Europe, probably since antiquity, and has become a hardy, generous annual or biennial, valued for beautifying rockeries and spring borders.
Where to buy it
Plant in spring or early autumn, avoiding spells of intense heat. Pick a plant with healthy foliage and roots that are not exposed. Best time: March, April, May, September.
Add this plant to my garden →Plants from the same family
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- Rocket SaladEruca sativa
- WasabiEutrema japonicum
Tips generated and checked by Viridia — adapt them to your local climate.