He said there was nothing he could do about 15% dearer plants caused by exchange rate changes, but Brexit had been good for no-one: "Our plants are 15% dearer. A £10,000 order is now £11,500. Demand for plants will go down and people will have less money to spend. Things are getting more expensive but you guys are on the same salary so it goes into a downward spiral."
Kolff said most plants are imported into the UK - around 80% - and that the UK industry will struggle to find workers to expand if the UK cuts off imports of plants and workers and tries to increase home production by 300%.
"Plants will be so scarce landscapers and architects will go out of business."
On Xylella, he said that if it reaches Holland, it will reach the UK too, so everyone needs to be vigilant and that UK growers should not "take advantage".
"I don’t like it when people take advantage get competitive advantage from it. Some people say they won't import any Italian stock to show how responsible they are but they hardly import any anyway. Take it very seriously but don't take advantage."
He said the Southern Italy affected areas are are not important to the nursery industry.
Kolff added that box blight and caterpillar were concerns and had caused box sales to fall, though alternatives such as ilex and taxus.
Kolff added: "My grandchildren might not know what a box hedge was."
At Four Oaks, Piante Zelari said the industry needs to work together to keep out the disease, adding that it no longer sells polygala or nerium. The company emphasised, as did Kolff, that Pistoia growers are geographically far from the affected zones.