Overview
Trifolium hirtum is a hairy annual clover in the Fabaceae, growing 6-16 inches (15-40 cm) tall with ascending to spreading, softly hairy stems. The leaves are divided into three oval leaflets up to 1 inch (2.5 cm) long, also covered in soft hairs. In late spring it produces dense, rounded flower heads 0.5-1 inch (12-25 mm) across made of many small rose-pink to lavender pea-shaped flowers, backed by a ring of bristly bracts. The heads dry and hold their seed, and the plant dies after one season, regenerating from a large seed crop the following year. Native to the Mediterranean region, it was introduced to California and other dry-summer parts of the western United States as a self-reseeding pasture legume and for erosion control on poor, dry slopes. Like other legumes it fixes nitrogen through root nodules, improving thin soils. It grows in full sun on dry, well-drained ground and tolerates low fertility and drought. It has naturalized along roadsides and rangeland, where it can spread beyond planted areas.
Native Range
Native to the Mediterranean region of southern Europe, North Africa, and western Asia. It has been introduced and naturalized in California and other dry-summer parts of the western United States, where it grows on rangeland, roadsides, and dry slopes.Suggested Uses
Trifolium hirtum is used as a self-reseeding forage and cover legume on dry rangeland, in erosion control on banks and roadsides, and as a green manure that adds nitrogen to poor soil. It suits large, dry, sunny sites rather than ornamental beds. Its reseeding habit means it can spread into nearby unplanted ground.How to Identify
Appearance
Size & Dimensions
Height6" - 1'4"
Width/Spread6" - 1'
Bloom Information
Rounded rose-pink flower heads open in late spring, mainly April to June. Bloom lasts several weeks, after which the heads dry and retain their seed. The plant then dies, leaving seed for the next year.
Detailed Descriptions
Foliage Description
greenGrowing Conditions
Sun Requirements
Requires 6-12 hours of direct sunlight daily
• Full Sun: 6+ hours of direct sunlight
• Partial Shade: 3-6 hours of direct sunlight
• Full Shade: Less than 3 hours of direct sunlight
Water & Climate
Water Needs
Drought Tolerance
Drought tolerant when established
Care & Maintenance
Care Guide
Trifolium hirtum grows in full sun on dry, well-drained soils of low fertility and tolerates heat and summer drought as it matures and sets seed. As a nitrogen-fixing legume it improves poor soils and needs no fertilizer. It is sown from seed in autumn in mild-winter climates, germinating with the first rains and flowering the following spring. Once established it self-sows reliably and returns each year without replanting. It does not persist in shade, wet ground, or heavy clay that stays saturated. Grazing or mowing after seed set does not stop its return.Pruning
No pruning is needed for this annual. Mowing after the seed has matured can be used to manage growth without preventing the plant from returning from seed.Toxicity
Non-toxicPlanting Guide
Planting Methods & Timing
Planting Method
direct sow
Direct Sow Timing
Autumn, with the first cool-season rains in mild-winter climates
Days to Maturity
180–240 days
Plant Spacing
6 inches
Companion Planting
Good Companions
