Black medic

Medicago lupulina

Low-growing annual or short-lived perennial in the alfalfa genus. Often turns up uninvited in lawns — usefully so, since it tolerates compacted soil and adds nitrogen.

Hardiness ratings

Black medic hardiness across the four zone systems
SystemRatingTemperature rangeHow to read it
USDA hardiness zone Zone 3–9 −40 °C to −1.1 °C Zones where it can be grown as an annual — not a frost-tolerance rating
RHS hardiness rating H7 down to −20 °C Plant needs at least this level of cold tolerance
Canadian plant hardiness zone Zone 3–9 −34 °C and warmer Zones where it can be grown as an annual — not a frost-tolerance rating
Australian (ANBG) zone Zone 1–5 −15 °C to 10 °C Zones where it can be grown as an annual — not a frost-tolerance rating

As a tender annual, Black medic doesn't overwinter — the zone range shows where the growing season supports it. See the RHS rating for its actual cold tolerance.

Growing notes

  • One of the few nitrogen-fixers that thrives in heavily compacted urban soils
  • Useful as a low-maintenance lawn component when mixed with grass and white clover
  • Reseeds freely; can become weedy in neat formal lawns

Categories

Related plants

Cross-check Black medic against your zones

Reference

Black medic on Wikipedia