Hide, who organised a meeting on "how to recruit and retain young people in production horticulture" at Chichester College last week, said: "Because we have a very highly motivated and readily available pool of agency staff we don't necessarily need in some respects the challenge of recruiting and retaining and developing young people in the same way as 20 or 30 years ago."
Should voters decide to leave the EU in the referendum on 23 June, Hide said talks he has had with "leave" campaigners suggest "bi-lateral arrangements" would come in with other countries to build worker arrangements similar to the former Seasonal Agricultural Workers Scheme.
Hide said there is a feeling that edibles and protected ornamentals are "not having the challenges" in recruitment and retaining staff that are being felt in other horticulture sectors. But he added: "Bringing younger people into a workforce of predominantly older people is very difficult. Young people need young people around them to encourage them to work for a company.
"Bringing in one apprentice in isolation is very challenging for that person. If you want to do that, you have to look back at how we got into the industry. There was greater tolerance of young people back then. We were allowed to make mistakes and be foolhardy.
Hide was awarded the RHS master of horticulture last week, which he said is a "summation of what you learnt during your horticulture career" and "offers a well-respected qualification" for those who may not have had the chance to take one of the diminishing places to study horticulture at university.