Top tips on making your own compost mixes

If you’ve ever wanted to learn more about making your own compost mixes, Garden Organic is the place to go – and with the ban on peat compost for home gardeners coming in this year, there’s never been a better time.

 Last week I joined a Garden Organic online talk about peat-free growing, which I can thoroughly recommend. Talks are helpful if you find it easier to learn through listening rather than reading, especially if the talker is as knowledgeable as our host, Anton. Having the chance to ask questions anonymously in the Q and A session is really helpful too.

A Garden Organic (GO) survey showed that very few gardeners make all the compost their garden needs; the majority use a mixture of homemade and shop bought. If you want to garden as sustainably as you can, GO has loads of advice on achieving this balance.  

A few things I learned:

  • Peat only came into use in the 1960s with plants being sold in containers in garden centres. Garden plants don’t need peat, which is virtually devoid of nutrients. Some countries, such as Australia, have no source of peat so their horticulture industry has never depended on it. 
  • In a bag of peat-free compost you will find:  wood fibre (a waste product from sawmills that is also in demand for use in bio mass boilers)/ composted bark (adds structure and air spaces)/ coir waste (a waste product from coconut plantations)/green waste compost (from council garden waste collections).
  • Growing media shouldn’t be used on a large scale to improve the soil – the resources used to make potting compost are limited. To improve soil, use garden waste compost, homemade compost, manures and green manures. To fill raised beds, use topsoil.
  • It’s a good idea to buy in seed compost because it’s difficult to get right yourself. Get the best you can afford because a little goes a long way. Seeds contain their own nutrients so they will germinate successfully in low-nutrient material with good drainage.
  • If you want to adapt multipurpose compost for use as seed compost, remove larger pieces, put through a coarse sieve, mix 50/50 with rewetted coir block.

Peat-free challenges

  • Peat-free compost behaves differently to peat – the main challenge is watering. Because of their high coir and woodchip content, peat-free mixes tend to dry out more easily. They also have a coarse texture, which can appear dry on the surface but still be damp further down.
  • With pots, watering little and often is best. Check by putting your finger in the mix to see if it’s dry all the way through. Water by going round the pot in a circle to get water to drain all over. Repeat a few times.
  • Water seed trays from below. Use a fine mister or waterer for the surface.
  • Peat-free compost doesn’t store as well as peat so only buy what you need. Don’t leave out in the rain; tiny holes in the bag will let in water which will wash away nutrients. Don’t subject to high temperatures by leaving out in glasshouse. Don’t buy bags that are faded as they might have been lying around for a while. If a mix smells bad it may have turned anaerobic, so return it.  

Feeding tips

A challenge with peat-free compost is that it can run out of nutrients more quickly – after 4 weeks.

  •  After 4 weeks, water with a sustainable liquid feed using comfrey or nettle leaves. Make your own comfrey feed by leaving 1kg of comfrey leaves in 15 litres of water for 5-6 weeks. Use neat to water plants.
  • For a concentrated comfrey liquid feed – stuff leaves into a drainpipe and let the liquid drip out of the bottom. Dilute 1 -10 and use on flowering and fruiting plants. This feed doesn’t smell – adding water is what makes the concoction smell.
  • Urine also gives a very good balanced feed (dilute 1 – 10). Fun fact – the average person produces enough nitrogen in their urine to fertilise 1 and a half tonnes of tomatoes, yet this usually gets flushed away to be treated at high expense, together with drinking-standard water.   
  • Use worm compost mixed with homemade compost as top dressing. Worm compost provides high levels of readily available nitrogen. Use sparingly.

For information and advice about making your own mixes, check out the GO website –  Garden Organic – Discover organic growing

Garden Organic recommends trying different peat-free composts to see which you have most success with. The charity has had good results with Melcourt’s Sylvagrow range for seed and potting mixes.

A word about peat

Garden Organic has long campaigned for an end to the use of peat in horticulture.  Peatlands cover 3 per cent of land surface but store 30 per cent of the earth’s soil carbon. Peat only regenerates at a rate of 1mm a year. In the UK, peat extraction accounts for 5 per cent of CO2 emissions. More than 95% of lowland bogs in the UK have been destroyed or damaged as peat has been extracted on an industrial scale.

Garden Organic’s online talks (webinars) are held on a donation basis to help support the charity’s work in helping people to garden organically. 

If you live near the charity’s Coventry base, you can attend courses or workshops in person, or else watch out for the next webinar. Online courses are also available and you can write in with questions too.

Julie

Compost your way to a peat-free future

The long-awaited ban on sales of peat-based compost comes into effect for home gardeners this year.

This isn’t the end of the story, however. For the professional sector, a phased approach will reduce use from December 2026 before a full ban comes into effect from 2030. This means that while some peat-containing products will be banned from shelves in 2027, others will be exempt until 2030.

The gardening charity the Royal Horticultural Society (RHS) encourages gardeners to take the matter into their own hands by making their own compost, as a free, easy and sustainable alternative to shop-bought soil improvers.

Professor Alistair Griffiths, Director of Science at the RHS, says: ‘Composting is one of a handful of small changes gardeners can make on their plots to help accelerate the UK’s transition to peat-free and for people to make a positive difference to the environment and the health of their plants and planet.’

The charity Garden Organic believes that if consumers are provided with the facts they will swap their peat-based compost for homemade or peat free.

It has long campaigned for the end to peat use through its For Peat’s Sake campaign and is committed to getting the word out to as many people as possible through gardening clubs, allotment associations, garden centres and schools. To join the campaign, go to Garden Organic – Discover organic growing  The website also has guidance on making your own peat-free compost mixes.

A long story

It’s been a long and winding road to get to this year’s ban and there is still wide-spread confusion.

In 2011 an agreement was reached between the horticultural industry and the Government that the use of peat-based compost would be gradually phased out by 2020, giving manufacturers time to develop good quality peat-free alternatives.  This was a voluntary agreement, but the Government said it would legislate if this was not successful.

 The 2020 deadline was missed, so in August 2022, Defra (Department for Environment, Food and Rural Affairs) announced a ban on the sale of peat and peat-containing products in the retail horticultural sector by the end of 2024.  Consultations carried out with the public showed support for going peat free. Of 5,000 people interviewed, 95 per cent were in favour of ending peat sales to gardeners.  

Then last year the decision was taken to delay the ban for the professional sector until 2026 (with some exemptions) before the full ban in 2030. Defra said the delay was to enable professional businesses to find other suitable peat-free growing alternatives. It said a balancing act was needed between protecting precious peatlands while also acknowledging difficulties faced by the industry in making the changes.

Peat-free alternatives include organic materials such as bark, coconut fibre (coir) and bracken.

With more than 7 million people having taken up gardening since the pandemic, demand for compost is greater than ever.  The amateur sector accounts for 70 per cent of sales of peat-based compost in the UK.

Why are peatlands precious?

Peat is an accumulation of partially decayed ancient plants in the earth’s wetland eco-systems, called peatlands or peat bogs. Because it is stored under water, the organic matter doesn’t release carbon as it decays. Many of these peatlands have been growing undisturbed for thousands of years.

The UK’s peatlands store three times as much carbon as its forests, but the vast majority are in a degraded state.  Estimates suggest that only 5-10 per cent remain in near-natural condition.

For peat to remain healthy it must remain wet – extraction dries it out, sometimes triggering wildfires, and the carbon inside the bog is released as carbon dioxide, accelerating climate change.    Emissions from peatlands make up over 4 per cent of all the UK’s annual greenhouse emissions – the equivalent of the carbon footprint of just under 2 million people.

With extraction, wildlife also suffers as animals lose their homes, and the local area loses a defence against flooding as healthy peatlands act as huge sponges.  

The extraction of peatlands was scaled up in the early 1960s for the horticultural industry. For decades it has been an ingredient in the majority of composts sold in British garden centres. It became popular as a fertiliser because it retains moisture and nutrients. It’s also inexpensive and easy to dig out and process into bags.

Environmentalists have long warned than digging up peatlands for use in gardens is a huge source of emissions and devastating for wildlife. The conservationist David Bellamy raised the issue of peat bog damage in the 1970s. Globally, peatlands store half a trillion tonnes of carbon. Environmental agencies say that any peat compost ban must include the importation of peat in potted plants.

Monty Don, presenter of BBC’s Gardening World, has said that using peat is ‘eco-vandalism’ and there is never any justification for using it.

When the delay to the ban was announced, Garden Organic expressed disappointment, not only at the delay but also the confusion that had been created.

Garden Organic’s chief executive Fiona Taylor said: ‘Peatlands are running out of time, and we need action now to stop the degradation of this precious eco-system just for the sake of our gardens and garden plants. Gardening should be about giving back to nature, nurturing plant diversity and soil health.’

She said the delays created a confusing marketplace for gardeners trying to do the right thing.

‘It’s good that gardeners won’t be able to buy bagged peat from 2024, but at the same time they could be buying it unwittingly via shop-bought peat-grown plug plants. ‘

Exclusions to the ban include a special dispensation for plug plants and mushrooms, which together made up 42 per cent of all peat used by professional growers in 2021.

The Wildlife Trusts have also been urging governments to enforce bans for the last 30 years. They say the burden should not be on the consumer to ensure they are not inadvertently buying peat-based products.

Research by the RHS last year showed that fewer than one in five nursery growers were peat free, but some had moved to peat-free growing in every main plant group, showing that the shift was possible for all plants.

 Despite the delays, the UK is far ahead of other countries in tackling the issue.    

The benefits of quality homemade compost are many – when added to soil, compost sequesters carbon, improves plant growth, conserves water and helps prevent nutrient runoff and soil erosion. Used as a mulch added in layers of 5cm on the top layer of soil, it suppresses weeds, improves soil structure and prevents moisture loss in hot weather.

And if you’re anything like us at Great Green Systems, composting can become a fascinating hobby too.

Spare Parts