Peat in horticulture

Plant Heritage Peat Statement

Sustainability is at the heart of our work as Plant Heritage. This statement explains our position on peat.

We recognise fully the value of peat habitats for biodiversity, carbon storage and water management and the need for their conservation. We support the transition to peat free growing media.

We also recognise the need for the horticultural industry to be prepared with suitable alternatives, at the required volumes, so that the integrity of the National Plant Collections is not put at risk. We encourage the growing media industry to work with the specialist knowledge of National Collection holders in developing suitable alternatives. We will continue to provide training and support for Collection holders and Plant Heritage members to help make the transition as soon as possible.  

We represent a diverse range of National Plant Collections, who play a valuable and specialist role in conservation. A small number of plant groups are adapted specifically to peat bog habitats. Though research is ongoing, peat free alternatives are currently limited in their suitability for these plants and rare taxa could be at risk of being lost. Where plants are under threat in their native habitat, ex situ conservation (such as the National Plant Collections) may be critical for the survival of these threatened taxa. We therefore believe there is a very limited exemption that should apply for peat obligate plants grown for conservation and research, until proven alternatives are available.

Read on for some case studies of Collection Holders making the transition to peat-free growing, and for links to advice and resources.

Robbie Blackhall-Miles, Banksia

Robbie grows a lot of peat-loving plants. As well as his Collection of Banksia, he also has Protea, Shortia and Vaccinium. Peat's texture, water holding capacity and long lasting nature, was seen as creating just the right environment for these plants. 

However, after trialling alternatives, he discovered they are just as happy in a mixture of well-rotted leaf mould and fine milled bark, with a helping of ground granite rock dust and occasional feeds of seaweed extract. The blueberry crop is now better than ever and some of his plants have been putting on three times more growth with this new potting mixture.

Margaret & David MacLennan, Galanthus

Margaret and David have a National Collection of Galanthus (snowdrops) and have achieved scientific status for the quality of their work. They conducted trials comparing the performance of peat free growing media with their usual John Innes mix. With more than 1,800 named varieties and species of snowdrops, everything is grown in lattice (aquatic) baskets plunged in sand. This means they need a good quality growing medium. 

For their experiment, they planted baskets with the same number of identical bulbs, using either the normal John Innes mixture, or the peat-free alternative made with bracken and sheep's wool. Four years on, the results were impressively in favour of the peat-free mix. Healthy snowdrops will increase naturally each season. However the number of bulbs in the peat-free pots was almost without exception greater than those of the John Innes pots. The bulbs were also cleaner, healthier looking and generally more plump. 

The Collection as a whole has now been replanted in peat free. They continue to research the best growing medium for the rarer and more difficult Galanthus species.