Nieburg is one of the country's largest suppliers of herbs to garden centres, with one million pots a year. He said the most popular sellers remain traditional favourites such as curled parsley, mint, chives and sage. "We are one of the few tightly focused on the herb market," he added. "There are fewer players now."
Country Herbs, based in Spalding, grows 200 varieties. Having year-round availability is key to keeping customers happy, said Nieburg. Xylella means imports from Italy face a "looming" biosecurity question mark and Brexit means garden centres may look to the UK to buy more product as import prices rise, he added. But the cost of buying in euros also means some imported machinery and input costs will rise, he pointed out.
Nieburg said herb sales have plateaued after rises caused by food television, healthy-eating trends and a move away from dried herbs. "We are probably the biggest pot-herbs-to-garden-centre specialist in the market these days," he added.
Meanwhile, "herb queen" Jekka McVicar has said British native herbs angelica and celery leaf are becoming more popular. She also suggested that lemongrass should be grown more in the UK.
McVicar pointed out that plant health concerns mean lemongrass cannot be imported, "just the sticky bit" of the plant. She said celery leaf "grows like parsley" and chicory, as a bitter herb, should come back because "we have lost bitter in our diet". The herb is good for digestion and for eating with fish, she added.
Promoting her Mr Fothergill's herb seed range, McVicar said: "Herbs can transform a meal into a feast." Top sellers in the range are borage, chives and white-flowering borage. Foraging and raw food trends are helping sales of the 47-herb range.
McVicar designed the Modern Apothecary garden at the RHS Chelsea Flower Show in May, winning silver gilt. She said she was thrilled for sponsor St John's Hospice. The garden has brought her design work and shown "I'm still alive", but she said she will not design at Chelsea again. McVicar will judge in the floral marquee next year and hopes to be a floral design judge in the future because Chelsea has a lack of female design judges.