Jarman said he would also not be recruiting any new members of staff.
"We have cancelled two job offers that were about to go out to candidates and we won’t be taking on any apprentices this year. We have stopped any capital expenditure which means we won’t be relocating our main site Manor Farm out of the village of Pensham to Hollyoak Nursery Little Comberton to reduce lorry traffic in the village.
Jarman pointed to increases in kerosene and tractor diesel prices of 3p a litre since the EU result was announced - saying his biggest fear is a reduction in retail demand "when the population realise what they done to the economy and their own personal circumstances".
By contrast horticulture industry figure Ian Riggs highlighted the fall in the value of the pound, which will make imports more expensive, from flowers, fruit, plants and vegetables, ultimately benefitting UK growers.
"This, if sustained, will result in price increases to the consumer - an effect of this will be to make UK produced crops more competitive, and increase demand, this may result in higher farm gate to UK farmers and growers."
He added that garden retail businesses that hadn't covered themselves for changes in the currency exchange rate extensively would find imports almost universally paid for in US dollars costing more - also freight rates - leading to higher retail prices.
This will effect everything from solar lights to garden furniture, said Riggs, and a huge range of gardening products and ranges.
Both Riggs and Jarman highlighted labour as a key issue. "I can see problems in those businesses that rely heavily on labour from the EU or overseas, especially those staff that work in the UK to transfer funds back to families in their country of origin, in effect their wages and funds sent home have fallen in value, currently about five per cent, £ against euro, although this is partially offset by the phased increases in the National Living Wage," said Riggs.
Jarman added: "Every one migrant employed on a seasonal zero hour National Living Wage contract growing and packing plants at Hayloft Plants supports two full time permanent fixed higher paid British/Commonwealth office jobs. We have two English workers on the nurseries and that’s it. We have tried and tried to get English workers on the nurseries, but it’s an impossible task and no doubt many of your readers will concur. You haven’t got to be a mathematician to work out what could happen at Hayloft Plants if migration is limited/stopped, I guess we are one of many horticultural firms in a similar position."
Added Riggs: "The greatest hurdle will be, as in previous periods of financial instability and uncertainty, that the public becomes very cautious with spending, especially the discretionary spend, preferring to hold onto their money. For the businesses that service our industry, they may find that plans or projects for new equipment, buildings, technology upgrades may be put on hold, or even cancelled, adversely effecting company performance.
"A future bonus area is plant health, where variable standards of inspection and enforcement in certain areas of the EU have long been a concern, a secure plant health border would be welcomed by all sectors.
"For home building and DIY the situation is two edged, house building will be decreased or put on hold, resulting in a decreased landscaping demand, reluctance to move house however may result in home improvements and upgrading, this may prompt some spend on the garden.
"The reduced exchange rate will certainly result in an increase in the staycation, as overseas holidays become more expensive, again this may result in greater spend on the room outdoors, so there could be an increase in spending on upgrading facilities at home.