Contractors were used across the huge project portfolio of the company, with 3,800 staff on its books.
Trelwaney Landscaping near Bodmin is owed £80,000 by Rok for fencing, turfing and planting. Future contracts with Rok were worth well over £400,000.
Director John Vokes said the downfall was "numbing and devastating". His 18-year-old business needed cash flow and he had sold a tractor and two dumpers. He said about 65 per cent of his work came from Rok and he has had to lay off four staff. "The knock-on effects were horrendous and we're clinging on. We hope a new company will call us back to all the unfinished jobs, but we can't do it unless they pay us something because we can't buy materials," he explained.
Meanwhile, new projects involving hefty tracts of landscape are on hold while PricewaterhouseCoopers (PwC) tries to find a buyer.
A £7m redevelopment of a science park and the upgrading of Arnish Point in Stornoway have been thrown into doubt. Smaller schemes, such as landscaping and fencing for Cheltenham Borough Homes, are also in limbo.
Subcontractors across the country are thought to face unpaid bills worth millions of pounds. PwC said: "Creditors usually receive a certain amount in the pound, but we have no view at the moment what that might be."
PwC made 711 redundancies last week, mostly from the maintenance and improvements business, said partner and joint administrator Mike Jervis. "We have had more than 100 expressions of interest in the business. There are still national contractors interested in all divisions," he pointed out. "We are shortlisting bidders on the basis of their size, level of interest in acquiring large parts of the business and their speed of reaction."
Rok was the second firm to collapse in this sector, following the administration of parts of Connaught (HW, 27 August).