The Horticulture Matters report to be presented to the Government on 14 May will call for the coalition to make seven pledges backing horticulture, including making the subject a part of key stage 1-4 at schools.
The survey and report has been commissioned by some 40 horticultural organisations, all of which are concerned about the "alarming" skills crisis threatening Britain's economy, environment and food security.
RHS director-general Sue Biggs has spearheaded Horticulture Matters, bringing together organisations including the Institute of Horticulture, Lantra, BALI, Royal Botanic Gardens, Kew, Landex and Grow to discuss the green-skills gap.
Some 200 businesses contributed to the report, with 72 per cent saying they cannot fill skilled vacancies, 90 per cent saying horticulture lacks careers appeal and 93 per cent demanding Government action.
The report will launch to 30 MPs, ministers and lords at the Houses of Parliament on 14 May with 20 industry representatives, including Leigh Morris, Carol Paris and Madge Moore. The group has made the pledges on behalf of the industry, decided by steering groups.
Biggs said: "We were keen it was not the RHS only. It would be easy to say it's all the Government's fault. We're a £9bn industry with 300,000 workers. We bring environmental, social and health benefits and food security. It's extraordinary that the Government doesn't take horticulture as seriously as we think it should.
"We are planning meetings with ministers and civil servants following the presentation of the report. This is not a posturing relationship - we want to be collaborative. There is a decline in botany and biology degrees, which is of real concern."
There will also be calls for degree and research funding, but Biggs accepted "we need to change the perception around horticulture and that's our responsibility, not the Government's"
Industry pledges to match those asked for from Government include one to nominate 100 Alan Titchmarsh-style ambassadors to talk to young people about the benefits of horticulture as a "glamorous, successful, satisfied, happy and healthy career".