The Enterprise Bill is set to be discussed in the House of Commons next week.
The HTA said: "In the debate, we hope MPs recognise the need for reform and the economic and social benefits of liberalisation at the local level, particularly for garden centres.
"Ultimately, we hope to see the policy become law and that local authorities take steps to implement it.
"The HTA believes that devolving the decision on Sunday trading to the local level is a logical step to bring it in line with the wider planning system, where local people have more say in how their communities are run. It will also promote consumer choice and level the playing field for bricks and mortar retailers, making it easier for them to compete with 24/7 online retail.
"The ability to trade for longer on Sundays could also provide a welcome shot in the arm for garden centres, 95 per cent of which are SMEs – allowing them to increase sales and significantly boost productivity making better use of existing assets and resources.
"This would in turn help to offset emerging cost pressures such as the implementation of the national living wage and pension auto-enrolment. A report from the British Retail Consortium (BRC) released on 29 February suggests that if left unchecked, such cost pressures and changing consumer habits, could have a detrimental impact on the retail sector – with employment falling by as much as a third by 2025.
"The HTA also welcomes Government efforts to strengthen the rights of workers in relation to Sunday working. The Bill will further protect those who do not wish to work, whilst providing opportunities for the many workers – particularly students and those looking for flexible part-time work – who value the ability to work on Sunday and would welcome additional hours.
"Indeed, in most garden centres, staff already work full eight hour shifts on Sundays regardless of trading hours, as plants need watering and pets for sale must be cared for. However, they cannot serve customers and are essentially unproductive during these shoulder hours; often spending much of this time turning customers away from the tills.
HTA chief executive Carol Paris added: "This amendment offers our members a great opportunity to boost productivity and will provide great support to our sector to mitigate against the additional costs of National Living Wage and pensions auto-enrolment which will start to bite next month."