Rob Hunt and Tony Barrell of PwC were appointed joint administrators of Solus Garden & Leisure on 15 May after failed negotiations for a buyout by Scotts and no other acceptable offers.
Solus made 91 of its 250 staff redundant on 21 May, blaming bad trading conditions and the "cessation of a distribution agreement with its major supplier". But it remains "hopeful of securing a sale".
Town & Country chief executive Barry Page said: "Solus was the best thing the industry had. They supported them (garden centres) for years in preseason elongated payments and service that was second to none.
"It's a bloody shame. Perhaps garden centres will appreciate what suppliers have done for them because they don't now."
Suppliers said Crest, Smart Solar, Gardman, Stax and Decco would pick up Solus's business. But there will be more direct sales and more work for garden centre buyers, who often used Solus for small top-up orders.
Mr Fothergill's commercial director Tim Jefferies said: "Solus is going to cause some difficulty out there. There's been more direct sales over the past couple of months. We picked up some lawn care, for instance, because we do direct."
Retail consultant Neville Stein said: "This is bad news for the industry. Solus provided an efficient and cost-effective way to purchase a wide range of stock. This is particularly important for the smaller centres who do not have a buying department and need smaller quantities of stock.
"Also, I am wondering what will happen to their own brands like Botanico. These brands seemed to be getting traction so there may now be a gap in the market."
Solus had a turnover of £29.3m in the six months to 30 March. It employs around 250 people, wholesales third-party products from companies such as Vitax and Hozelock and also owns the Yeoman, Joseph Bentley, ChapelWood, Garden Nation and Bermuda brands.