Pentanema squarrosum
Pentanema squarrosum · Asteraceae
The gardener's calendar
Ideal time to plant pentanema squarrosum: set it out when the soil is neither frozen nor waterlogged, and water generously as it establishes.
ID card
- Common name
- Bristly Oxtongue
- Family
- Asteraceae
- Type
- Perennial herbaceous plant
- Foliage
- Deciduous
- Flowering
- July to September
- Mature size
- 60 to 100 cm in height
- Hardiness
- Hardy, down to -15°C
- Origin
- Mediterranean region and South-West Asia
Care
Sunlight
Plant Pentanema squarrosum in full sun for generous flowering and a compact plant. It tolerates partial shade, but good light promotes vigor and color. Avoid overly shaded areas where flowering would be reduced.
Soil and drainage
This plant prefers well-drained, dry to moderately moist soil. It adapts to poor and chalky soils. Avoid constantly wet or waterlogged soils, which promote fungal diseases. Adding sand or gravel improves drainage if needed.
Watering
Water regularly when planting and during active growth, especially during prolonged dry periods. Once established, the plant tolerates dry periods well. Reduce watering in winter and let the soil dry slightly between waterings.
Fertilizing
No fertilizer is strictly necessary if the soil is properly prepared at the start. A light application of balanced fertilizer in spring stimulates growth. Avoid excess nitrogen, which would promote foliage at the expense of flowering.
Pruning and maintenance
Prune the plant after flowering (October-November) to maintain its shape and encourage branching. Remove spent flowers regularly to extend the flowering period. Spring pruning, before new growth begins, can rejuvenate aging plants.
Diseases and pests
This species is generally robust and rarely affected by pests. Powdery mildew may appear in humid and warm conditions; improve air circulation. Root rot is the main risk if there is permanent water excess.
Did you know?
Pentanema squarrosum, formerly classified under the genus Inula, belongs to the large Asteraceae family with more than 30,000 species. Its Latin name "squarrosum" refers to its floral scales that spread characteristically, like the scales of a pinecone. Traditionally used in Eastern herbal medicine for its tonic properties, this medicinal plant fascinated botanists in the 17th century.
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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- WormwoodArtemisia absinthium
Tips generated and checked by Viridia — adapt them to your local climate.