Peat-Free Growing Media UK

The peat conversation in British horticulture has moved on from whether to how fast. Retail went first, professional use is following, and most growers now have a date in the diary rather than a policy to watch. What is left is the practical work: which crops are hard, what replaces peat in each one, and how much of the season you lose getting it right. We supply peat-free growing media to UK growers from our own facilities in Sri Lanka. Coir, graded by crop, buffered as standard, with the lot report shipped alongside the goods so the numbers you plan around are the numbers you receive.

Where the rules stand

Bagged peat compost for amateur gardeners came off the shelves at the end of 2024. The professional side has been messier. Defra originally signalled 2030, then brought the intended date forward to the end of 2026, with time-limited exemptions carrying certain uses toward 2030. Plug plants and mushroom production sit inside those exemptions, which matters more than it sounds: together they accounted for roughly 42 per cent of all peat used by professional growers in 2021.

The Horticultural Trades Association has argued against the earlier date, and the position has moved before. Check the current legislative status through official sources rather than any supplier’s website, including this one. What you should not do is assume it will slip again and plan accordingly. Plenty of businesses did that in 2023.

For the full picture, including the exemptions and a crop-by-crop transition plan, read our guide to peat-free growing media for professional growers.

What actually replaces peat

There is no single material that behaves like peat, which is the first thing to accept. What there is instead is a set of components with different strengths, blended to approximate what a given crop needs.

  • Coir brings water buffering, predictable particle grading and structure that survives multiple seasons.
  • Wood fibre brings air and drains quickly, but settles and ties up nitrogen.
  • Bark adds structure and some disease suppression.
  • Composted green waste brings nutrition and batch-to-batch variation in roughly equal measure.

Coir-led blends do most of the work in substrate production because the material is consistent, ships compressed and reuses well. The question stops being what replaces peat and becomes what ratio, for which crop, with which fertigation strategy.

Blends by crop

Rooting depth, irrigation frequency and salt tolerance differ by crop, so the substrate should too. These are the tolerances we hold to, lot by lot.

CropPith to chipEC (1:1.5)pHAir-filled porosity
Glasshouse tomato70 : 30under 0.80 mS/cm5.8 to 6.318 %
Cucumber60 : 40under 0.80 mS/cm5.8 to 6.222 %
Capsicum and aubergine70 : 30under 0.70 mS/cm5.8 to 6.219 %
Tabletop strawberry50 : 50under 0.50 mS/cm5.5 to 6.028 %
Blueberry30 : 70under 0.40 mS/cm4.5 to 5.532 %
Leafy and salads95 : 5under 0.50 mS/cm5.6 to 6.014 %
Propagation and plugs100 : 0under 0.50 mS/cm5.6 to 6.016 %

Propagation carries the tightest tolerance of the lot. Young roots have no buffer against salt, so plug material is washed and buffered beyond the production grades.

The three things that go wrong in a transition

1. The fertigation schedule comes across unchanged

This costs growers more money than anything else on the list. Peat and rockwool release water differently from coir, and a schedule tuned to one will either waterlog a coir slab or leave the crop short by mid afternoon. Both get blamed on the substrate.

Smaller shots delivered more often, a first irrigation that waits for real transpiration, and an overnight dryback in the 8 to 12 per cent range. Our coir irrigation guide gives target ranges by crop stage.

2. Calcium gets quietly displaced

Peat is relatively inert. Coir has cation exchange capacity, so it interacts with calcium, magnesium and potassium in the feed. Unbuffered material releases potassium across the first weeks and displaces calcium, which shows up as blossom end rot in tomatoes or tip burn in lettuce, in a crop you fed plenty of calcium.

Buffered material arrives with calcium already on the exchange sites, which removes the problem at source. Check the potassium figure on the lot report: properly buffered coir comes in well under 150 ppm. Our guide to washed, buffered and raw grades explains how to read the rest of the sheet.

3. The trial is too big to learn from

A trial that compares one bench against a whole house is an anecdote. Run one line or one house, same climate zone and same irrigation controller where possible, record root zone EC and pH weekly rather than at the end, and decide the success criteria before you start.

Trialling with us

Trial pallets are available for most formats so you can run the material through a short cycle before committing to container volume. They ship with the same lot documentation a full order carries, which means the trial data and the production data are comparable.

Send your crop, your structure type and your current substrate and schedule. We would rather flag a fertigation problem before you plant than diagnose it in week six.

Sustainability, with the numbers attached

Coir is a byproduct of the coconut industry. Nothing is extracted to make it, nothing has to regenerate for a century afterwards, and it composts at the end of its life rather than needing a waste route.

Two things worth knowing if you are being asked sourcing questions by a retail customer. First, coir ships compressed, which makes its transport footprint far better than the distance suggests. Second, reuse spreads that footprint across multiple crops, which is why the soft fruit sector’s habit of running bags for two or three seasons matters environmentally as well as commercially.

Our facilities run fresh water rinse cycles with settling and reuse, and we hold a greenhouse gas emissions certification assessed by Meo Carbon Solutions in Germany alongside GMP certification for manufacturing practice. Our guide to the Responsible Sourcing Scheme for growing media covers what UK buyers are starting to ask for.

Frequently asked questions

When does the professional peat ban take effect in the UK?

Defra’s stated intention has been the end of 2026 for professional use, with time-limited exemptions extending certain uses toward 2030, including plug plants and mushrooms. Industry bodies have contested the earlier date and the position has moved before, so confirm the current status through official sources before building it into a crop plan.

What is the best peat-free growing media for commercial growers?

There is no single best option. Most commercial blends are coir led for water buffering and structure, with wood fibre or bark added for air and drainage. The right ratio depends on crop, container size, cycle length and your irrigation system.

Will peat-free media cost more?

Usually more on the invoice, sometimes less overall. Coir ships compressed, which reduces freight per litre, and coir-led blends in substrate crops often carry two or three seasons where peat carries one. Run the cost across the full crop cycle rather than per bag, including disposal.

Do I need to change my fertiliser programme?

Almost certainly. Coir has cation exchange capacity that peat largely lacks, so calcium, magnesium and potassium behave differently in the root zone. Most growers raise calcium and magnesium relative to their old recipe. Have an agronomist rework it rather than adapting the peat programme.

How long should a peat-free trial run?

Two full seasons where the crop cycle allows. The first season teaches you the irrigation, the second tells you whether the result holds.

Can I blend down rather than going fully peat free?

Reduction blends have been a sensible transition route for several years. Whether a partial blend remains legal after the deadline depends on the final exemption framework, so plan toward full replacement and treat a blend as a stepping stone.

Talk to our UK contact

Tell us the crop, the structure and what you are running now. We will come back with a blend, a format and a trial quantity.

Chaminda Fernando, United Kingdom
Telephone: +44 74 3885 1955
Email: marketing@cocolabs.lk

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D.G.Substrates (Private) Limited has steady evolved over the last two decades to be a leading provider of advanced solutions for horticulture, home and garden, pet care and environment technologies.

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Contact

Hotline : +94 76 457 0350
Kishen (Germany):
+49 177 141 6846
Chaminda Fernando (UK):
+44 74 3885 1955
Head Office
Battramulla, Sri Lanka