Marsh mallow
Althaea officinalis · Malvaceae
📷 Wikimedia Commons · CC BY-SA 3.0
The gardener's calendar
Marsh mallow is in full bloom: enjoy it, watch watering in hot weather and let spent flowers feed pollinators before pruning.
ID card
- Foliage
- Deciduous
- Flowering
- July to September
- Adult size
- 120 cm in height
- Family
- Malvaceae
- Hardiness
- Very hardy
- Origin
- Mediterranean basin and Western Asia
- Soil type
- Well-drained, tolerates moist soils
✓ Taxonomy verifiedSource: AI estimate · hardiness: reliability high.
Expert tips
The key tip
Althaea officinalis loves moist, light, well-structured soil. Water regularly during dry seasons.
The common mistake
Leaving old, dead stems in place over winter thinking it's useful; the plant becomes scraggly and flowers poorly.
The pro's trick
Sow in situ in autumn (September/October) in bare soil: young seedlings that emerge in spring are more vigorous than remaining stems.
Care
Exposure
Marsh mallow appreciates full sun for optimal flowering. It tolerates partial shade but develops better with at least 6 hours of direct sunlight per day. A sunny location promotes flower production and the concentration of active compounds.
Watering
Keep the soil regularly moist, particularly during spring growth and summer. Marsh mallow tolerates moist soils and resists well to dry periods once established. Avoid prolonged waterlogging which could rot the roots.
Soil and planting
Plant in well-drained soil, rich in organic matter. Marsh mallow adapts to most soil types, including slightly alkaline soils. Adding well-decomposed compost at planting time improves establishment and vigor.
Pruning and maintenance
Prune in spring by removing dead wood and shortening stems to stimulate branching. You can cut the plant back to 20-30 cm from the ground after winter. At the end of the season, cut dry stems to prepare the plant for winter dormancy.
Fertilizing
A balanced fertilizer application in spring is generally sufficient. Avoid excess nitrogen which would promote foliage at the expense of flowering. Well-decomposed compost or manure spread on the surface in spring can replace chemical fertilizer.
Diseases and pests
Marsh mallow is globally robust. Watch for rust and leaf spots in humid weather: ensure good air circulation around the plant and avoid overhead watering. If attacked, remove affected leaves and improve air circulation around the plant.
Did you know?
Marsh mallow owes its name to the desert of the same name and its soothing properties known since Antiquity. The Egyptians and Greeks already used it to soothe irritations. Traditionally in Europe, the roots were cooked, mixed with honey and sugar to create a confectionery: this is the ancestral origin of the « marshmallow » treat we know today!
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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- Swamp hibiscusHibiscus moscheutos
- Flower of an hourHibiscus trionum
Tips generated and checked by Viridia — adapt them to your local climate.