Bents Home & Garden, which celebrates its 80th anniversary this year, has up to 500 full and part-time staff at peak season in December. They used to have staff rooms in portable cabins.
Managing director Matthew Bent said: "We want to give as good facilities at the back of the business as at the front of Bents." He said the development would help with staff retention and recruitment.
With Aldi to pay £8.53 (£9.75 in London) an hour from 1 February, above the £7.20 minimum wage (£7.50 from 1 April), Bent said Bent's offered attractive staff benefits, conditions and facilities on top of wages that appeal to its staff.
The centre has developed from being a rose nursery to opening its first cafe in 1982 and rebuilding under the guidance of Ernest Wertheim in 1995. There are 1,000 covers now in several eating areas including a new bistro. The company is now sometimes at capacity with catering and aims to spread customers around the site with satellite cafes.
Chairman Ron Bent said: "We realised people only bought plants or Baby Bio four times a year but they could buy coffee every day. That's the number one attraction to the business now." He said when Starbucks came to the UK, Bents was already well placed to take advantage in the upsurge in interest in coffee shops.
He said the centre had made a "long journey" from the 1930s to when his father bought land in the 1950s, showing the Bents' principle of investing in the business.
Longest-serving staff member nursery supervisor Stuart Bateman celebrates 50 years at the company this year.
Speaking about recent trade, Matthew Bent said Christmas 2016 sales were "mixed" and had not hit high targets. Catering did well, but he said Black Friday was a distraction and sales were flatter after that, and he wondered whether customers were showing "uncertainty where to spend their money".
He said more retailers were competing for Christmas spend and he planned to differentiate product more from supermarkets and other retailers at Christmas 2017.
He said overall 2016 was "ahead of the market but slightly under budget".
Bent said the new £30m RHS Bridgewater garden, a few miles away at Worsley, could bring more gardening customers into the north west and that he hopes to work together with the RHS when Bridgewater opens in 2019.
Plans include to revamp the main restaurant, which is 15 years old, and to make a leisure destination such as a day spa on the first floor, which is currently storage, above Bents' concession avenue.
Matthew Bent said just 20 per cent of shoppers went upstairs so straight retail on the first floor would not work.
The birds of prey rescue centre at Bents Garden & Home could be transformed into a miniature golf course if plans are approved.
A planning application to convert the area, which was the previous home of Wild Wings rescue and rehabilitation centre, has been submitted to Warrington Borough Council and is now under consideration.