The campaign against peat has had a lower profile recently, but behind the scenes, a slow move towards alternative growing media is underway.
Under the UK Biodiversity Action Plan, drawn up in 2002, Britain was to cut its peat use to 40 per cent of the overall market by 2005. This target was met comfortably, with a peat-free figure of 47 per cent. At that time, the 90 per cent target for 2010 seemed ambitious but achievable. But now, with two years to go, the figure sits at just 54 per cent.
According to a Defra representative: "We have said the target would be challenging, and accept that it will not necessarily be met. But use has already been cut by a significant amount, and that will serve as a jumping-off point for any future measures."
Such measures will include a peat-free promotion by the HTA-backed Growing Media Initiative (GMI) early in 2009, aimed at raising the profile of alternatives among the public.
Advocates of peat reduction point out that more than 90 per cent of the UK's species-rich lowland-raised bog has been lost recently, owing to pressures from agriculture and forestry. The world's peat bogs also tie up twice as much atmospheric carbon as its forests. Yet the UK market for horticultural peat amounts to 2.5 million cubic metres a year.
Major retailers have already latched on to peat reduction as a way of bolstering their green credentials. Britain's biggest garden centre chain, Wyevale, launched its environmental policy earlier this month, with an explicit commitment to reducing sales of peat-based growing media and plants grown in them.
Wyevale sustainability director Dr Alan Knight says alternatives have needed time to evolve. "I blame the Greens in the early 1990s for peat-free's failure so far," he says. "They suggested too big a change, too quickly. We need more managed change."
The company aims to achieve what the wider industry has not managed so far: namely to drastically cut peat use to enable 90 per cent peat-free within two years. Wyevale has already been meeting with supplier-growers to discuss moves towards this. According to the company: "Trials have shown that quality is not compromised and currently the cost impact is being assessed."
The sticking point has been growing from seed, according to the policy, which states: "If nutrient levels could be reduced sufficiently so that the compost is suitable for seed germination, it would be possible to replace peat entirely for most consumer applications."
DIY giant B&Q has already committed itself to similar reductions in peat-based sales, though the company cautions: "Our ability to achieve these targets will depend on a number of factors, including the availability of alternatives of sufficient quality and in the necessary volumes."
The consequences for the industry are hard to predict. Scotts Professional sales manager Dave Steward says: "It's a difficult question because there are a lot of different parameters. People are clearly moving towards peat-free, but it's a gradual increase rather than a tremendous rush. We know that some retailers have taken a stance on the issue, though, which affects pull-through."
It seems this, rather than demand from customers, will be the driver of any immediate change, he says, adding: "We don't think the Government's own target will be reached."
Scotts will nonetheless tailor its range to the market as it finds it, and has just launched two new peat-reduced varieties of its Levington-branded consumer compost.
"We were always able to produce peat-reduced or peat-free products," says Steward. "But we still find peat the most effective, as do many growers. When your livelihood depends on growing plants successfully, you will use the best products available."
Scotts has worked with growers to carry out trials with a number of alternative media. "We have had some good results with peat reduction," Steward says. "But there is no ideal solution. Different plants have different requirements. Some will always need peat."
Clover has previously been a name synonymous with peat. But the company has developed Wonder Grow, a general-purpose peat-reduced compost with added stimulants for both ornamentals and edibles use.
The Northern Ireland-based company has launched a number of other products this season, including a compost formulated for container growing of trees, shrubs and roses, and a bumper-sized tomato and salad crop bag.
Sales manager Andrew Peers says that the company has no need to apologise for continuing to promote peat-based products. "None of our sites are Sites of Special Scientific Interest (SSSIs)," he says.
Research and development manager Andrew Mather adds: "They are about 20-30ft (6-9m) deep and we take only the top two inches (5cm). We are a long way off working out our sites. We have a policy to leave some behind. And the law is tight on what you can and can't do."
Peers is also sceptical about the carbon-sink argument. "Peat is still regarded by the EU as a 'renewable fuel source' for power stations," he says.
White Moss is another growing media supplier with its own peat reserves - a 120ha site on the outskirts of a Merseyside industrial estate. Owner and former Growing Media Association chairman Graham Eardley says: "It's not a Special Area of Conservation (SAC) candidiate - it has no conservation value. We are not destroying pristine raised mires."
He argues that horticulture has a minor role in peat-bog depletion as it uses only six per cent of what is harvested. "If you're going to impose targets and limits, what about the wagons coming over from Holland?" he asks.
However, White Moss also processes more than 50,000 tonnes of green waste a year, and uses bark from the timber industry. "We supply whatever growers want," says Eardley. "It's not for us to dictate. But the majority of what we sell is 100 per cent peat."
He agrees that the move towards alternatives "hasn't progressed very quickly". He believes that "even people who are quite anti-peat are now thinking that, rather than go to extremes, they'll use a mixture - that could include green waste or bark as well as peat."
The driver has to come from the garden centres and the sheds, he adds. "It won't happen until growers are told by their customers: 'We don't want peat.' We use green waste in consumer products, but it's different on the professional side, although a few are trying it."
William Sinclair Horticulture is another firm accommodating the gradual transition to peat-reduced horticulture. "We are always trialling new products and mixes at nurseries," says sales manager Andrea Marshall. "Growers are willing to try things, and we already use bark, wood fibre and coir, which some plants prefer for its root-growth properties."
Root growth in any medium can also be promoted by including loam from wormcasts in the mix, she adds. "It's full of micro-organisms which dramatically improve root growth."
As to the idea that peat-reduced plants may need more watering, she says: "Peat-free pots may look dry on top, but are wet lower down. It's one of the things people have to get used to."
And Westland, which has promoted peat-free media in collaboration with the Eden Project since 2003, has this year launched multi-purpose peat-free compost under the Earth Matters label, aimed at the burgeoning grow-your-own market. And Humax has introduced a multi-purpose organic peat-free grow bag in response to consumer demand.
But while the big growing media suppliers have all bases covered, others have nailed their colours to the peat-free mast. Melcourt supplies bark and wood-fibre products to growers who mix their own. Research and development co-ordinator Catherine Dawson says: "It's an ever-bigger market."
Dawson, who is also chairman of the GMI, says the environmental case against peat is changing. "It used to be more about habitat protection. Now it's more about the role of peat bogs as carbon sinks."
But even growers unconvinced about the environmental case are using alternatives in their compost. "There are very few growing media that don't have a dilutant, but for technical rather than environmental reasons," she says.
Botanicoir supplies coir that is a by-product from coconut mills in Sri Lanka. "We are aiming at the professional market," says director Samantha Balasuriya. "It's a renewable source, biodegradable, and more environmentally friendly. It also has an excellent air-to-water ratio, which is good for roots."
Many growers are unconvinced, however. Pentland Plants partner David Spray says: "Peat-free is too expensive, and not always as environmentally friendly as you might think. Coir has to be shipped half-way round the world. It also costs more - an extra 5p a tray. And the public aren't asking for it."
He says peat reduction has a role, though. "You can have a 50:50 mix and maintain the plant quality, with the peat serving as a buffer. We have tried green waste from a big depot in Edinburgh, but we found it inconsistent compared to the uniformity of peat."
Aware of the poor reputation that some peat alternatives have, Cumbria-based Dalefoot has spent six years developing a growing medium out of bracken and sheep's wool. Co-owner Simon Bland says he has had to overcome growers' often negative experiences of peat alternatives.
"People don't think the alternatives work as well as peat. Coir, for example, doesn't hold on well to water. But we aim to provide something that's as good as peat that's also natural and sustainable," he explains. "The bracken is high in lignin and potassium, while the wool retains water and provides a slow-release supply of nitrogen."
Both are sourced from Bland's own or neighbouring farms. "That way, you know that the sheep haven't been dipped," he explains.
The company sells two versions: a ready-to-use form for the consumer market and a double-strength form in 30-litre sacks, which the end user mixes with equal quantities of soil or spent compost. "How sustainable it is depends on how much transport is involved," says Bland.
Dalefoot has lately been concentrating on winning over sceptical customers, with trials at the RHS and in various consumer gardening titles, and an appearance at BBC Gardeners' World Live. "It takes a while," Bland says. "In trials it has performed better than peat, apart from with seeds. But one of the aims is long-term nutrient release, which wouldn't show up in a six-week trial."
Bland concedes that this comes at a cost - around £6 for a 30-litre bag. "It's a premium price for a premium product," he says. "But by the time you've mixed the double-strength product, the price is comparable."
So far, efforts are concentrated on the consumer market, selling mainly through mail-order. A peat-free ericaceous compost is planned for next year. "The next step is to get into one of the large retail outlets," Bland says.
He concludes: "Supplying the commercial grower is another step on, although I have supplied samples to several nurserymen already who have gone on to order more. Growers are looking for fast results and ours work over the longer term - and it does benefit the end user."
WISER WATER USE
Ensuring that plants take up water efficiently has long taxed the minds of growing media developers. But two recent products claim to have found solutions.
Hydrosonic from William Sinclair Horticulture is a soil humectant that reduces the need for watering by up to 50 per cent, but also gives plants a longer shelf life. Sales manager Andrea Marshall says: "With it being a powder, it can be more readily accessed by the plant than a gel."
Scotts has launched H2Gro, a granular wetting agent aimed at the containerised nursery stock market, but which can also be used on plugs and in trays. The company says the granules continue to assist water uptake for a full year.