There are 400 million hectares of peatland on earth and 86% remains undisturbed. Of the 14% that is disturbed, horticulture accounts for far less than 1%. Forestry and agriculture are the main reasons for peatland disturbance.
Horticulture. Using peatlands does have an impact on the environment, both on the local species and on global warming. The amount of peat used for horticulture is a very small part of this issue. The claim that harvesting peat for horticulture is reducing either the amount of peatlands or available peat reserves is not supported by the data. Peat reserves are increasing faster than they are used for horticulture.