Garden compost and potting compost – why you need both

By | April 18, 2018

Use compost! But which one, garden compost or potting compost? You need both in the garden and we help you make the right choice with this post.

Garden compost

forking over. potting compost

Fork over soil around perennial plants and add well rotted compost.

Garden compost is homemade from anything that will rot down, usually a mixture of mostly kitchen and garden waste plant material. Find out how to make it here.

Well-made compost is brown and crumbly, smells of the forest floor in autumn, and is almost good enough to eat.

Geoff Hamilton

  • Great for improving fertility if you work plenty into the soil.
  • Good as a mulch to keep soils moist.
  • Excellent at breaking up sticky clay soil.
  • Handy for turning fine sandy soil into more useful crumb-sized particles.

Garden compost is no good for sowing seeds or using in pots and containers.

Potting compost

You use potting compost for sowing seeds, taking cuttings and growing plants in pots and containers. Although it’s possible to make your own, most of us buy it in sacks from shops and supermarkets.

Peckover House, Wisbech, Cambridgeshire. extension. containers. potting compost

Pots and containers at Peckover House, Wisbech, Cambridgeshire. © Dave Catchpole and licensed for reuse under https://creativecommons.org/licenses/by/2.0/

Composts have traditionally been a mixture of soil, peat, sand or grit and balanced fertilisers. They have a good structure so they hold moisture, and yet are free-draining and allow air to penetrate. They are sterilised so they don’t carry any weed seeds, pests or diseases. The John Innes loam-based potting compost recipes, for example, have been used for decades.

When you’re buying potting compost, think what job you want it to do. Then choose a sack which will do that job: sowing seeds, potting up seedlings, potting larger plants, potting houseplants, potting mature plants or shrubs in containers, or special needs such as acid-loving (ericaceous) plants or orchids. If you don’t have any special requirements then multi-purpose compost will work.

If the sack doesn’t say ‘peat-free’ then the compost will probably contain peat. You might like to consider choosing a peat-free compost. There is worldwide concern about the destruction of environmentally important peat bogs. As a result, there are now some very good peat-free composts, such as Sylvagrow, on the market. These composts grow good plants and can be even better than peat. They include ingredients such as coir (a waste product of the coconut industry), wood fibre, composted bark, sawdust, wood and paper waste.

Some local authorities sell ‘green compost’, made from the green waste collected from households, as a soil improver or mulch. Some also mix it with other ingredients to make potting compost.

Time to get out in the garden now?