Mulch is the simplest, most underrated soil improvement we know. A 3-5 cm layer on top of any garden bed reduces watering by a third, suppresses most weeds, moderates soil temperature, and slowly feeds the soil as it decomposes. The choice of mulch material matters less than most articles suggest, but different mulches do suit different climates and bed types.

This guide compares mulches for cool, temperate and warm climates, with notes on what we use and what we have stopped using.

Reference guideYear-round applicationMultiple climates

Why mulch quietly transforms a garden

  • Cuts evaporation by 25-50% in summer.
  • Suppresses 80-90% of weed seedlings.
  • Moderates soil temperature swings.
  • Adds organic matter as it breaks down.
  • Reduces compaction from rain or irrigation.

Mulch options by climate

Cool, wet climates (Pacific Northwest, UK)

Shredded leaves: free, abundant in autumn, breaks down over a season.

Straw: traditional, looks tidy, slightly slug-friendly.

Wood chips: long-lasting, good for paths between beds.

Skip: peat moss (sustainability concerns and questionable benefit).

Temperate climates

Compost mulch: feeds soil while protecting surface.

Grass clippings (dried first): nitrogen-rich, decomposes fast.

Straw or pine straw: easy to source.

Warm, dry climates

Wood chips: long-lasting, helps moisture retention.

Gravel or pebbles: reflective, suits Mediterranean herbs.

Bark mulch: long-lasting but slow to add nutrients.

Choosing mulch by bed type

Vegetable beds

Compost or shredded leaves. Both add nutrients and don’t need removing before planting.

Perennial beds

Wood chips or bark. Long-lasting, attractive.

Herb beds (Mediterranean)

Gravel or coarse grit. Reflective, drains well, suits dry-loving herbs.

Pathways

Wood chips or bark. Suppresses weeds; durable underfoot.

How thick to apply

  • Vegetable beds: 3-5 cm.
  • Perennials: 5-7 cm.
  • Paths: 8-10 cm initially; top up annually.
  • Around tree trunks: never directly against the trunk; leave a 5 cm clear ring to prevent rot.

When and how to apply

  • Spring: Apply after soil has warmed, around planting time.
  • Autumn: Top up before winter to protect against frost.
  • Avoid: Applying mulch on cold wet soil; it traps cold.

Mulches we have stopped using

  • Black plastic: looks ugly, becomes brittle, contributes to microplastic in soil.
  • Coloured wood chips: aesthetic dye that leaches and offers no soil benefit.
  • Pine needles in heavy clay: keeps soil too acidic over time.
  • Cardboard alone: useful as base layer under wood chips, less so on its own.

Further reading

Two authoritative resources we recommend if you want to go deeper on this topic:

Frequently asked questions

Slightly, yes, especially in cool wet climates. Straw and wood chips offer slug shelter. Bare soil with paths is drier and less slug-friendly. The tradeoff is moisture retention versus slug pressure.
Yes for fine-seeded crops (carrots, lettuce). Pull mulch back, sow, then replace once seedlings are established.
In cold climates, a winter mulch protects roots from frost damage. In mild climates, less necessary.
Annually for most beds. Wood chips last 2-3 years; leaf mulch lasts a single season.
Straw, because hay contains seeds that sprout as weeds. Worth the small price difference.
Jay Sharma
Written by

Jay Sharma

Jay Sharma edits Farmora Living. He grew up around a working kitchen garden and has spent the last several years testing equipment, growing methods, and small-space food setups in his own courtyard and rooftop plot before writing about them here. His pieces lean on what a first or second year of practical growing actually looks like, on tool reviews grounded in real seasons of use, and on the small shortcuts and honest mistakes that only surface after you have done the work yourself.

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