The delphinium grower who supplies prize blooms to King Charles’s Highgrove estate has shared his top tips for protecting plants from slugs and snails.
Nicholas Langdon, of Blackmore & Langdon, won gold at this year’s RHS Chelsea Flower Show with an extraordinary display of towering delphiniums fit for a king.
Speaking to the Express at his stand in the Great Pavillion, he revealed the secrets behind achieving award-winning blooms.
“The key thing for delphiniums is drainage. They don’t like being too wet through the winter,” he said.
“And for slugs, nematodes work really well, along with anything coarse. So coarse grit, broken eggshells, anything slugs don’t like crawling over.”
Nematodes are tiny microscopic worms used as a natural form of pest control, targeting pests in the soil.
But Mr Langdon said winter protection is often overlooked by gardeners.
“The most important time to protect them is actually in winter. Most people forget about them when they go dormant, but that’s when the slugs get down and lay their eggs in the crown,” he said.
“And that is what kills the crown. You want to protect them from autumn through winter even more than in spring.
“You don’t need to dig them out. Just protect them with nematodes and grit and stop the slugs getting to the crown.”
He added that prevention is key, with gardeners often focusing on slug damage above ground while missing the threat lurking beneath the soil.
