Barley

Barley is one of the oldest cultivated grains, but in the garden it earns its place as a cover crop and green manure rather than a harvest. Among the cereal cover crops it is the fastest to establish and the most adaptable - it germinates in cool soil, tolerates drought, poor fertility, and even mild salinity, and puts on biomass quickly enough to outrun weeds. That speed makes it the go-to nurse crop for a tired bed you want to rest, bare ground you are reclaiming, or a patch being prepared for a future planting.

Its value is mostly underground. Barley sends down a dense, fibrous root system that loosens compaction and threads through the top foot of soil, scavenging leftover nitrogen and potassium that would otherwise wash away over winter. When it is cut or winter-killed, those roots and the top growth break down into organic matter - fertility you grow in place rather than buy in a bag. Left standing, it also shelters ground beetles, spiders, and other overwintering beneficials, and its roots and residue hold soil against erosion on slopes and open beds.

Sow into bare or lightly scratched-up soil so the seed makes good contact, then keep it moist until it sprouts - usually within a week or two. In cold zones a fall sowing winter-kills and leaves a protective straw mulch on the surface; in milder zones it overwinters green and is cut down in spring. Either way, cut or mow it before the seed heads mature so it does not reseed where you don't want it, and leave the tops in place as a chop-and-drop mulch for the soil life to pull under.