Which Clover Is Best as a Cover Crop in My Garden?

Clovers are reliable nitrogen-fixing cover crops that suit a longer approach to soil improvement. Unlike phacelia or mustard, which you sow and incorporate within a few months, clovers are better suited to beds that will be left under cover for a full winter and into spring, or even through an entire growing season if one bed can be rested. The nitrogen they fix accumulates over time and delivers a strong benefit to whatever follows them.

Red Clover — the Workhorse

Red clover (Trifolium pratense) is the most widely used clover for green manure in the vegetable garden. It is reasonably winter-hardy, establishes well from August sowings, and produces bulky leafy growth through late summer and autumn. Red clover can be left over winter and incorporated in spring. A full season of red clover can fix 80–150kg of nitrogen per hectare — enough to make a meaningful difference to a brassica bed the following year.

White Clover — Low-Growing, Long-Lasting

White clover (Trifolium repens) is the most persistent of the clovers. It spreads by stolons along the soil surface and can remain in place for several seasons. This makes it more suitable for paths, orchard floors, and longer-term fertility plots than for beds in active annual rotation, where its persistence can become a problem. It fixes nitrogen reliably but produces less bulk than red clover.

Crimson Clover — Fast and Showy

Crimson clover (Trifolium incarnatum) is the fastest-establishing clover and produces striking red flowers beloved by pollinators. It is less cold-hardy than red clover — it may be killed by a severe winter below -10°C — so it is better suited to mild coastal gardens or to spring and early summer green manure use. Sow in late summer, allow it to flower for pollinators in early autumn, then cut and incorporate before winter.

How to Sow Clover

Clover seed is small. Broadcast at 3–4g per square metre over a firm, raked seedbed. Rake lightly to cover with a thin layer of soil. Keep moist until germination, which takes one to two weeks. Sow red and crimson clover between July and early September for a winter-through-spring cover. Autumn sowings of red clover work but establish more slowly.

Weed Suppression with Clover

Clover is not as effective at suppressing weeds as phacelia or mustard. It is low-growing and slow to cover the ground fully. For maximum weed control, keep the seedbed as weed-free as possible before sowing, and be prepared to hoe emerging weeds during the first few weeks before the clover closes over.

When to Incorporate Clover

Dig in red clover in spring before it flowers and sets seed. Once seed is set, plants become harder to incorporate and the clover can spread from seed. Cut at ground level, chop roughly, and dig in. Allow three to four weeks before planting the follow-on crop. The soft leafy material decomposes quickly in mild spring conditions.