Red clover

The two-year window

Red clover is a short-lived perennial in garden practice. The first year builds roots and leaves; the second flowers strongly; after that the stand thins and weeds move in. Treat it as a two- or three-year crop and plan to resow rather than expecting a permanent patch.

That short life is also its value. Red clover fixes nitrogen, feeds bees and can be used as a green manure or undersown in grass. If you cut it after flowering, it regrows; if you let some plants seed, the patch may renew itself. Harvest flowers in the peak year, not the decline.

Growing it

PFAF gives USDA zone 5–9 and describes red clover in meadows and pastures, usually on circumneutral soils. In a garden, give it full sun and a weed-free seedbed. Sow in spring or late summer, about 5 mm deep. Inoculate the seed with the correct rhizobium if your soil has never grown clover.

Keep the patch moist until established. Mow or cut after flowering to encourage regrowth, and let a few plants self-seed if you want it to persist. Red clover is often grown as a green manure or undersown in grass; in a flower bed, give it its own space.

Harvest and drying

Pick the flower heads when they are fully open and the colour is strong. Harvest in dry weather, in the morning. Use scissors and take the head with a short stem.

Dry the heads in a single layer in a dark, airy room. They are bulky and need good airflow to avoid mould. Once dry, store them whole in a paper bag or an airtight jar away from light. The flowers fade quickly, so check them during drying.

1. Pick fully open, strongly coloured heads.
2. Harvest in dry weather, in the morning.
3. Dry in a single layer with airflow.
4. Store whole; check for fading or mould.

Identifying it

Red clover has trifoliate leaves, often with a pale V-shaped mark, and rounded pink-purple flower heads made up of many small pea flowers. The plant is hairy and the stems are hollow.

White clover (Trifolium repens) is a different, lower-growing species. Other clovers and medicks can look similar. Do not harvest from a mixed pasture without confirming the species, and avoid areas treated with herbicide.

Traditional context

Red clover has a long history as a forage crop and a traditional spring tonic. It contains isoflavones, which are phytoestrogens and the reason for most of the modern safety discussion.

NCCIH notes that red clover extracts have been used in studies for up to two years with apparent safety, but that supplements may be unsafe in pregnancy or breastfeeding. MSK adds that people with hormone-sensitive cancers should avoid it and that it may increase bleeding risk. This page gives no dose or treatment plan.