This 116 per cent decrease equates to a two per cent fall in sales but rises in costs for labour (two per cent), variables (4.5 per cent) and fixed costs (five per cent). Businesses surveyed averaged annual turnover of £0.5m.
The University of Reading research by agriculture and food investigation team members Richard Crane, Helen Christopher and Rod Vaughan shows what a poor spring growers had in 2013.
The researchers had problems getting figures from some of the biggest nurseries. Overall, the survey covers the 60,000 full-time businesses of England's 120,000 farm and horticulture businesses.
The full research is due to be published in February after being verified by Defra.
British Protected Ornamentals Association chairman Ian Riggs said: "In truth, we've had three bad years in 2011, 2012 and 2013. All I wish for in 2014 is a normal weather-pattern year. We'd like an average and unremarkable year."
Meanwhile, Nursery Business Improvement Scheme (NBIS) manager Will George warned that bedding growers are missing out on the opportunity to improve their profitability by comparing their costings and benchmarking through the NBIS. The are no bedding growers in the scheme, which currently has 12 members.
The NBIS began in 1995. Growers send quarterly figures to the HTA and receive a benchmark report. The figures compare seeds, marketing, transport, labour, water and other overheads, comparing sales, waste and surplus. Members then share approaches to cost-saving.