Less than a fifth of compost products at garden centres are clearly labelled as peat-free, according to a survey for conservation organisations.
A third of the 238 volunteers who took part in the survey for Friends of the Earth, Plantlife, RSPB and the Wildlife Trusts did not find peat-free compost clearly available at retailers and half of those who checked prices found it was more expensive.
The environmental groups are calling for more action to give green-fingered householders more chance to buy peat-free products to prevent the destruction of vital peatlands in the UK, Ireland and elsewhere.
Peat-free gardening is backed by leading gardeners including Alys Fowler and Monty Don, who has said "no garden on this earth" is worth the peatland destruction.
Peat bogs are home to unique wildlife. They store carbon that must be kept in the ground to stop it contributing to climate change, reduce flood risk and filter water, the campaigners said.
The survey revealed that only 19% of almost 1,300 products found on sale were clearly labelled as peat-free and most respondents reported a lack of product choice, price incentives or clear labelling to encourage people to avoid peat.
Industry figures show bagged peat-free compost increased from 5.9% of the market in 2011 to 9% in 2015.
Peat still accounts for more than half the material used in bags of compost despite commitments from industry and the UK Government to phase out its use by amateur gardeners, the green groups said.
In 2015, more than half the UK's peat came from the Republic of Ireland and around 7% from elsewhere in Europe, while around a third came from peat bogs in Scotland, England and Northern Ireland.
The environmental groups want governments across the UK to take urgent steps to end peat use in horticulture, and for industry bodies, leading DIY stores, garden centres and other retailers to work more quickly to introduce sustainable, high-quality alternatives.
All retailers should stock more high-quality peat-free choices and promote them, while local authorities and public sector bodies should publish their current use and their plans to stop using peat, they urged.
As homeowners gear up for Easter, one of the biggest times of the year for gardening, they are being urged to only buy peat-free compost and raise the issue with their local retailers and even their MP.
Sandra Bell, Friends of the Earth campaigner, said: "This survey highlights a clear need for faster and more determined action by the garden industry and retailers to meet the UK Government's commitment to phase out peat use from amateur gardening by 2020."
Adrian Thomas, RSPB wildlife gardening expert, said: "The quality of peat-free composts has really improved in recent years and I think they're now just as good if not better than peat.
"The bottom line is that it is important that in making our own garden a wonderful place, we don't damage a part of the planet elsewhere."