The armed forces charity Gardening Leave will close at the end of 2015, with the loss of 13 jobs.
The charity, formed in 2007, uses horticultural therapy to help veterans deal with mental health issues and adjust to civilian life.
An announcement by Gardening Leave’s trustees on the charity’s website said income in autumn this year had fallen below the anticipated level and it did not expect the situation to improve in the short or medium terms.
Gardening Leave employs 13 staff on a mixture of full-time and part-time contracts, all of whom will be made redundant.
The charity said it was in active discussions with other organisations about the future of the services it provided. The charity said it was talking to the "appropriate parties" about its four sites in central London, Dundee, Ayr and Glasgow.
According to the Charity Commission’s website, Gardening Leave’s income has fallen significantly in the past few years, from £475,128 in the year to 31 March 2012 to £304,837 two years later. Spending also fell in that same period, from £511,011 to £267,657.
Announcing the closure, the statement from Gardening Leave’s trustees said: "Our priority now is to do the best we can for the armed forces veterans who attend Gardening Leave’s projects and our staff. We will be in touch with our veterans to discuss the alternative mental health support options available to them.
"This has been a very difficult announcement for us to make and we know it will be heartbreaking for all the charity’s staff, veterans, volunteers and supporters as well as the trustees, particularly at this time of year.
"We would like to thank our loyal supporters, who have fundraised and raised awareness of our work, as well as our dedicated staff team and our volunteers. Gardening Leave has achieved such a lot since it was founded in 2007 and we are all incredibly proud of the support the charity has provided to veterans in need over the years."