There is a "chronic shortage of available land to build glass in the south, especially on the West Sussex coastal plain", according to West Sussex Growers Association (WSGA) planning consultant John Hall.
Planning remains the WSGA's biggest issue as old glasshouse areas in the region are steadily being demolished to make way for housing, he explained.
VHB Littlehampton has 16ha of glass at its Zuider Zee and Holland sites being readied for demolition, which is believed to be the largest single area of glass ever to be demolished in the UK.
The site has been rented by Hall Hunter and Roundstone and occupied by Fargro. Fargro is moving to nearby Poling, with Persimmon Homes developing the site.
Hall said the rented Vitacress site at Angmering is also planned to be developed, with operations moving to its Runcton base. But he added that developers are not targeting old nursery sites and south coast towns have been swallowing up nursery land for development over the course of many years.
"In the South East there is so much housebuilding going on that by definition, because a lot of nurseries sit on the edge of conurbations, they will be built on."
Hall said he is "up to his neck" in discussions with local authorities about new local plans for WSGA and private clients to get planning permission for new glass.
Fargro technical director Dr Paul Sopp said the company is set to move from its 3.2ha area of the 48ha site in 2015.
WSGA chairman Graham Bryant added: "That site has been detailed for development for a number of years and they have taken glass further along the coast to balance that out."
The site also includes the old Yoder Toddington site. Also up for redevelopment for housing is the VHB herb unit at Angmering.
Pinetops move - New base at HRI Efford
Pinetops Nurseries based in Lymington, Hampshire, is set to move to HRI Efford in 2015, with the old site soon to be converted into housing.
Work is already well under way building new houses on the old Livermans nursery, which is to the west of Littlehampton.
Other nurseries that have been lost to housing in Arun District Council area in recent years include Peter Bailey Cucumbers and Irelands Nurseries at Ford and the old GCRI (Glasshouse Crops Research Institute) Littlehampton, which was given over to houses, along with Darlington Mushrooms.