Seven out of 10 enquiries to the Professional Gardeners' Guild legal helpline are about housing as the National Trust plans to halve the number of gardener jobs with tied accommodation by 2017.
The trust plans to cut the number of positions for gardeners with tied accommodation from 94 to 48 and concerns about the issue were raised at the guild's annual general conference.
A consultation with National Trust staff and the Prospect trade union started last year, partly because it emerged that in many cases HMRC regards some tied accommodation as a taxable perk. Prospect is in pay discussions with the trust.
National Trust people project manager Karen Dickin said the organisation's approach has become "out of step" with other groups and it decided to base staff housing decisions on business need rather than historic arrangements. "We wanted to make sure that we reward staff consistently and transparently through a salary. This will be fairer to other employees in similar roles and ensure we are compliant with tax rules.
"Living on site is not always as desirable as it may seem, particularly with the demands of a modern working environment and the extra responsibility it entails."
The National Trust and Prospect have agreed a fixed sum of between £10,000 and £15,000 to "buy out" those with a contractual right to housing. But Stevenson said salaries do not automatically go up after gardeners move out. The trust agreed to stretch the three-month standard notice period to 12. Dickin said the trust recognises that the move is "unsettling for affected staff".
Prospect officer John Stevenson said the response from members has been mixed. "It's not a clear picture. Those who had been in tied accommodation for longest were worst affected. In some cases they thought they would be there for the rest of their lives. But some people were saying: 'I'm on call 24/7, get me out of here.'"
He added that the real issue is the "poverty pay" in professional gardening. "It's a low-paid profession and it shouldn't be because of the skills, qualifications and expertise gardeners have. These people are looking after historical gardens that are rated the best in the world and they don't receive the pay that they should get."
The guild is also working on an advisory pay scale for all employers of gardeners to reflect experience, skills and qualification.
Guild chairman Tony Arnold pointed out that another general employment issue is that gardeners have to undertake training for their own safety and to comply with the law, but their employers do not always pay for the courses.
Tied accommodation - Little change in private sector provision
Professional Gardeners' Guild vice chairperson Susan Russell, head gardener at Culzean Castle, National Trust for Scotland, said in her experience gardeners are not being forced out but, as people with tied accommodation leave, their replacements are not offered housing.
An National Trust for Scotland representative said: "Decisions on housing provision for any property-based role are taken after consideration of the specific needs of that property and the responsibilities of the role. In some cases where it isn't possible to provide suitable accommodation, a fixed-rate supplement is paid instead."
In the private sector the number of jobs that come with housing has not changed much over the past 15 years, according to recruitment agencies. Mike Fuller, managing director of English Country Gardeners, a division of Horticruitment, said: "Generally it's only for senior positions. Tied accommodation attracts a wider selection of candidates. Clients realise it opens up their options."
Marian Baker of Andersplus Horticulture said live-in vacancies tended to be the most remote jobs. Both consultants said that, on average, the salary for a job without accommodation was around £5,000 more.