Gardeners have never had it so good when it comes to nature-friendly, peat-free composts for sowing seeds, potting up plants, filling pots and containers, or for simply improving our garden or allotment soil.
By John Walker. Published in The Telegraph, 11th October 2014. Last update: September 2016.
I sowed these Verbena bonariensis in a peat-free mix and grew them on in Vital Earth Multi Purpose Compost (1).
This is officially my best-ever year for peat-free gardening. I’ve been growing beautiful as well as productive plants without peat-based composts for many moons, but this season has been exceptional – and it’s not just thanks to a good summer.
My self-awarded accolade is down to the fact that today’s good-quality peat-free composts are better than they have ever been.
My onion sets got off to a flying start in SylvaGrow, which is the same peat-free compost that professionals use.
Modern peat-frees are easy to use, requiring no specialist skills, and they will grow most plants with ease. Despite persistent myths, they are as straightforward to use as peat-based mixes, and the results will be just as good, if not better. They are good for sowing seeds and for rooting cuttings. Some even match peat for sheer crumbliness.
“Modern peat-frees are easy to use, requiring no specialist skills, and they will grow most plants with ease”
Modern peat-free composts can be used for growing flowers, vegetables, fruit and bulbs. These are my ‘ecobulb’ tulips putting on a fine display, all without even a crumb of peat…
Mining peat destroys a natural habitat and it liberates carbon which was previously locked safely away. I don’t need to be part of this when good, consistent composts made from truly renewable materials, such as bark, wood fibre, British sheep’s wool, bracken, coir (from coconut husks) or composted green waste, are easily available. In the past few years, I have tried out nearly 40 peat-free composts. I’ve sorted out the bad and the ugly, and now have a shortlist of reliable good doers for anyone who asks. My selection includes a peat-free mix used by professional growers – SylvaGrow – which was introduced in 2014, is endorsed by the Royal Horticultural Society (RHS), and has received two Which? Gardening magazine Best Buys: for container composts (April 2015), and for compost for raising young plants (January/February 2016).
Do remember that with peat-free compost, as in so much of life, you tend to get what you pay for. Peat-frees do differ from other composts, but only in small, subtle ways. Here’s how to get the best results from them…
Fit for purpose
Check you’ve got the right product for the right job. Peat-free compost for sowing, propagating and potting up is different from that sold as a soil conditioner/improver. The latter is intended for mixing with soil outdoors, or in a polytunnel, to add organic matter (usually composted green waste) to new beds or to planting holes.
These trailing petunias grew so well in Gro-Sure Peat-Free All-Purpose Compost that they produced a solid mass of roots by the end of the summer.
Always choose fresh, intact bags of seed or multipurpose peat-free compost which aren’t faded, ripped, sodden or heavy. Beware cut-price bags that have been kicking around for years. I try to buy my compost from suppliers who store it under cover. Compost isn’t obliged to have ‘use by’ date, but it should.
Sowing success
If you sow lots of small seeds, a peat-free seed compost from Carbon Gold or Fertile Fibre, and SylvaGrow or Wool Compost for Seeds, all have a fine texture poured straight from the bag.
Choose a fine, crumbly peat-free for sowing smaller seeds. These cosmos came up fast in SylvaGrow, and no hard crust formed.
Other mixes, based on wood fibre and green waste, tend to be coarser. For smaller seeds I simply fill a pot to within 1cm (½in) of its rim, then use an old kitchen sieve to cover this with a finer layer. I then sow seeds onto this, covering them only if necessary. For other easy-to-handle seeds, I sprinkle un-sieved compost over them. Standing pots in a clean tray of tap water (to avoid damping-off disease) waters them gently from below, and prevents a hard crust from forming on the compost.
Don’t fret over fungi
Toadstools regularly pop up from among the roots of my tomatoes and seem to encourage even stronger plants.
Peat-frees tend to be bursting with unseen microbial life. This can appear as white ‘mould’ on the compost and on the inside of the bag, but it’s nothing to worry about. I often find small toadstools popping up in mixes that are high in bark and wood fibre, but they’re doing no harm to my plants.
“I grow without peat because I want my garden to give more than it takes from the natural world”
Some of my best tomatoes have been grown in pots where toadstools (not to mention the odd toad) have appeared. This is no surprise: fungi decompose organic matter, releasing plant foods as they do so. Many peat-frees are blessed with beneficial, plant-friendly fungi which are largely absent from sterile and ‘dead’ peat-based mixes.
White mould inside a bag is nothing to worry about – it just means that the compost is alive and healthy.
Home delivery
Locating a good, reliable supplier of quality peat-free compost can be frustrating, and peat-based products still tend to elbow them out. Fortunately, Carbon Gold, Fertile Fibre and Dalefoot Composts (suppliers of Wool Compost) all offer a reliable mail order service. Clubbing together with friends or your gardening club members to place a larger order can save money (a pallet load of peat-free is likely to work out cheaper than everyone buying their own bag separately).
Pot and tap
My proven potting technique is pretty foolproof. I overfill a pot with peat-free, tap it firmly three times, then brush off any excess so that the compost is level with the top of the pot. I then use a finger to make a hole for either large seeds or for plug plants, pop them in, tap once again, and water thoroughly.
Pumpkins and squash thrive in New Horizon Organic & Peat-Free Multi-purpose. This winter squash F1 ‘Confection’ is ready to plant outdoors (2).
Avoid firming compost with your fingers, or it’ll become compacted and drain less well. Adopt the same ‘tap and settle’ method with larger containers. Most mail order plug plants and young potted plants are still grown in peat-based compost, but both can be potted straight into a peat-free mix and will grow just as readily.
Wise watering
Once you’re used to it, peat-free compost is as easy to water (and feed) as any other. I use two rules of thumb to check if watering’s needed. If a pot feels heavy on lifting, it’s probably moist enough, but if it’s light, and the plant’s wilting, it needs a drink. To be sure, I push a finger into the compost surface: if it’s dry on top but moist beneath, leave watering until later.
The natural wool fibres in Wool Compost mean it holds onto moisture better, giving containers of vegetables and flowers the edge during the heat of summer.
Most peat-frees contain enough food for 4-6 weeks (check guidelines on the bag), after which you should begin regular feeding. Miracle-Gro Peat-Free All Purpose Enriched Compost contains a slow-release fertiliser which feeds for up to three months. Wool Compost needs less frequent watering than other peat-frees, and is especially rich in nutrients. It’s available in different strengths if you want to blend your own potting mixes.
“Remember that with peat-free compost, as in so much of life, you tend to get what you pay for”
Organic stamp
For those who want to be as organic as possible, from seed to plate, Carbon Gold and Fertile Fibre both offer coir-based peat-frees, certified by the Soil Association for organic growing (both also make compost used by commercial organic growers).
I used organically-certififed Carbon Gold Grochar Peat-Free All Purpose Compost to grow a delicious harvest of pea shoots.
Ericaceous options
To grow acid-loving plants, such as azaleas, blueberries and camellias in containers, peat and lime-free potting composts are available. Sylvagrow Ericaceous Compost is available from garden retailers (check here for stockists), and Ericaceous Wool Compost (from Dalefoot Composts) by mail order.
‘Green’ peat?
There is a kind of truly environmentally friendly peat, which doesn’t involve any habitat destruction. Moorland Gold is made from crumbs of dark upland peat, which is washed into reservoirs by natural erosion, and then extracted by filtration. It is organically accredited and available from The Organic Gardening Catalogue.
DIY peat-free
My home-made peat-free is a 50:50 blend of mature leaf mould and worm-worked garden compost, both sieved. I use this as an all-round mix for sowing seeds and for potting up. It works a treat, but it always contains some weed seeds.
Tomatoes flourish in my 50:50 mix of leaf mould and garden compost, which encourages masses of strong roots.
When I’m sowing, I tap and level a pot of compost, sow the seeds, then cover them with a bought (and therefore free of weed seeds) peat-free. The seedlings that come up are from the seeds I’ve sown. Any weeds that appear after pricking out seedlings or potting up plug plants, can easily be nipped off
My pick of the best peat-free composts*
Some manufacturer websites offer a stockist locator, but always check that a garden centre or other retailer stocks what you want before setting out (and if they don’t why not ask them to).
• Carbon Gold Grochar Peat-Free All Purpose Compost – carbongold.com
• Fertile Fibre Multipurpose Compost – fertilefibre.com This mix received a Best Buy from Which? Gardening magazine for container composts (April 2015).
Quality peat-free composts do well in hanging baskets. These Surfinia petunias are thriving in Miracle-Gro Peat-Free All Purpose Enriched Compost.
• Gro-Sure Peat Free All-Purpose Compost – gardenhealth.com
• Miracle-Gro Peat-Free All Purpose Enriched Compost – lovethegarden.com
• New Horizon Organic & Peat-Free Multi-purpose Compost (reformulated in 2015) – gardenhealth.com
• SylvaGrow (multipurpose) and SylvaGrow Ericaceous Compost – sylvagrow.co.uk
Check out my blog for news about new SylvaGrow All Purpose Peat Free Growing Medium with Added John Innes, SylvaGrow’s endorsement from the Royal Horticultural Society (RHS), and its two Best Buys from Which? Gardening magazine.
• Bord na Móna Growise Peat Free Multipurpose Compost has replaced Vital Earth Multi Purpose Compost (more information here) – thegreenergardener.com
• Wool Compost – dalefootcomposts.co.uk
Can you recommend a peat-free equivalent of John Innes no 3? Something for permanent shrubs and trees in containers?
A good question, Kathy. Vital Earth actually offer a peat-free equivalent of John Innes No.3, but you will probably need to track it down, and it doesn’t appear to be available in very big bags. Wool Compost would probably fit the bill. It’s rich in nutrients and has good moisture-retaining qualities (from the wool fibres which are in the mix). There is a ‘double strength’ version to which you could add some quality loam for long-term planting. Good luck.
This is a great article, thanks John.
So far I have started trialling New Horizon and Dalefoot. So far they both seem nice, although the Dalefoot has a wonderful texture. But it is much more expensive. Although I love it, I don’t think I can afford it with so many pots to fill.
With the John Innes formulas, I wondered if it would work to just mix in some garden soil with the peat free? After all, John Innes is just a mix of loam and compost?
Thanks, Jack. Good to hear you are trying out more than one peat-free compost. I wish more gardeners would give several mixes a go side by side – it’s a great way to get a feel for how different mixes work and land on one that’s just right for you. In my trials I had around 40 different mixes on the go at one stage, and I learnt a lot.
I think a top quality, modern peat-free is worth paying what seems a little more for. Often with these mixes, they’re the result of many years of development and refinement to give gardeners products that do what they say on the bag. We’ve gotten so used to the ‘three bags for a tenner’ mindset we’ve forgotten that good quality compost is an investment that pays off. Always working down to a ‘low’ price also encourages inferior products, both peat-based and peat-free. It’s interesting that many peat-free gardeners are quite savvy about how they use compost. Many are using the more finely-textured blends like Wool Compost for seed sowing and the early stages of plant raising, but are switching to more multipurpose mixes for potting up containers.
I wouldn’t mix any garden soil in with a peat-free. All quality composts are formulated to give good growing results straight from the bag. Garden soil is best left in the garden. That said, I’m always experimenting with leaf mould (which I have oodles of) mixed with different bought peat-frees. It contains few nutrients or weed seeds and I find it successful for bulking up the coarser peat-frees (e.g. Miracle-Gro PeatFree All-Purpose Enriched Compost) when planting spring-flowering bulbs.
The original John Innes composts were a mix of loam, sand/grit, sphagnum peat and fertiliser/lime. If you buy them then you’ll still be using peat. If you want a peat-free version try SylvaGrow or Growise.