Scott said the Government response to the Killian Pretty Report, which aims to save £300 million and enable more smaller businesses to develop their premises without needing full planning permission, will mainly impact on planning for extensions under 50sq m.
Malcolm Scott added that most garden centre extensions were usually larger than that.
The changes will mean less red tape to change doors and windows, add ATMs and disability access.
But Scott said the legislation was more aimed at town centre businesses than out-of-town garden centres.
He added: "It's designed to free up planners' time. But that means they may spend more time on garden centre applications."
Malcolm Scott is currently working on an application at Hayes Garden World in Leeds and has won a greenbelt application at Kemps Plants, near Bristol.
Work has also begun on the first phase of development at Palmer Gardens, Trowbridge, Wiltshire, a garden centre and café owned and managed by national employment charity Shaw Trust. Planning permission was gained by Malcolm Scott Consultants in August 2008 on behalf of Shaw Trust for the erection of a canopy over the plant sales area and improvements to car parking.
Scott said: "In the current economic climate where many major development projects are being put on hold, more modest proposals such as those at Palmer Gardens are a good way to boost business and ensure continuing success."