The gardens in Llangathen, Carmarthenshire, is looking to take on around a dozen students for its second intake on the 14-month Heritage Horticulture Skills Scheme.
Each student receives a £10,000-a-year bursary from the Heritage Lottery Fund.
Head Gardener Joseph Atkin said: "We need to fill the skills gap in heritage-skilled gardeners and we’ve got some real belters coming through. The crux of the course is that it’s really, really practical.
"The diaries our students keep are up to Kew standards and they have plant idents really pummelled into them. There is no age limit, our training gardeners range from 18 to 50 but you need a little experience and a level 1 qualification."
Students gain an RHS level 2 qualification in practical horticulture and a level 2 Lantra qualification and traditional skills taught include seed gathering and old –fashioned methods of lifting large trees.
Atkin said the open day on Friday would include practical demonstrations of traditional horticultural methods. Students, teachers and senior garden staff would be on hand to offer advice and more information.
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