The nursery, based near Ashford in Kent, surveyed 100 professionals in advance of its "Design for Maintenance" soft-landscape workshop on 17 September. It found that 88 per cent think an industry formula indicating future maintenance costs would be useful. More than 80 per cent said it might raise the status of and demand for skilled horticulturists.
Marketing manager Nick Coslett said: "The survey indicates that there are more opportunities for us to focus on aftercare. Designers have the ear of the client at the point of making investment in green infrastructure."
Conference speaker and landscape architect Richard Sneesby is keen to tackle the problem, which is most acute in the public realm.
He said he has seen "hundreds of examples of green spaces full of weeds, full of bicycles" where there is plenty of capital funding to create them but a proper maintenance budget either never existed or circumstances changed and then it was cut.
"Over time things start to become more and more disappointing and they start to lose the quality of the original idea. The garden festival sites that were supposed to regenerate rundown areas in places like Liverpool, for example, have now been fenced off because they are overgrown and dangerous.
"We need to think that if a garden costs £50,000 to create and a 10th of that to maintain a year then by 10 years it's a £100,000 garden."
Sneesby added that he agreed to talk at the conference because he wants to see whether a way can be found to build in a realistic idea of future maintenance into the design process.
Of the survey respondents who do provide future maintenance costs as part of their designs, only 41 per cent give a detailed breakdown. Most of those who do not said the client does not request them. However, 84 per cent of respondents said they think their clients would benefit from the knowledge.
The event, which also features garden designer and writer Dr Noel Kingsbury and RHS Garden Wisley curator Colin Crosbie, will be held at the Ashford International Hotel in Kent and costs £25 to attend. See www.palmstead.co.uk to register.