Roper said Blue Diamond only used self-generated cash for new centres, all funded from cash flow and has an estate of half lease and half freehold centres. Roper said he would like a facility to have cash available for a bigger purchase such as Garden & Leisure, but not through private equity funds.
Guernsey-based Blue Diamond has 600 shareholders and shares are traded between them.
The share price has risen 163 per cent in 10 years and earnings share has jumped by 321 per cent.
He said Blue Diamond spent £1.5m on its estate a year.
Roper said empowerment of staff was important and department heads had to have ownership and were more important than shop mangers in bigger shops.
The group is to launch a new customer-loyalty scheme offering benefits, not points on offer, such as a plant doctor service to be run by Peter Burks.
A multi-platform website is due to launch this year with a click-and-collect service ready by spring 2016 to enable core gardeners to go straight to products they want.
He said there had been vertical growth in planted containers for 7-8 years and colour was another important factor in sales, with purple osteospermum not selling and burnt orange taking over, for instance.
Roper said eight years years ago he did a GIMA talk along with James Barnes of Dobbies, but the chain now had different aims, with Dobbies aiming at C1 demographics and Blue Diamond at AB1’s.
He said Terra Firma chairman Guy Hands’ wife visited Blue Diamond’s Guernsey centre and that Hands had " been and given his cheque and gone away again". Roper said Blue Diamond had "no plan to sell up".
Roper said new acquisitions were won against competition from Wyevale private equity owner Terra Firma, but said while "money is important there are other values which family businesses respect".
Of the 17 centres, he admitted Spalding Festival "was a mistake" so he turned it into a clearance outlet centre and re-negotiated the lease. It is now a profit contributor to the group.
He said Grosvenor was "draining" the Grosvenor estate but "now the estate gets a good lease from us".
Roper said Fermoys would be developed within two years.
Blue Diamond - facts and figures
17 centres with £85m turnover projected for 2015
49 per cent gardening; 51 per cent non-gardening
£71m 2014 turnover
Stuart Whalley head of gardening
James Nuttall head of plants
Heidi Newton head of fashion
Home head to begin in June