What garden pesticides can you still buy, and why were so many withdrawn?
Far fewer than a decade ago — a large number of active substances have been withdrawn from the amateur market following reviews of their effects on health, on pollinators and on water, and the products remaining are mostly of a different kind.
The categories, since they are frequently confused:
Herbicide — kills plants.
Fungicide — controls fungal disease.
Insecticide — kills insects.
Molluscicide — slugs and snails.
Collectively these are pesticides, and all are regulated as such.
Why so much has gone:
Pollinator harm. Neonicotinoid insecticides were restricted following evidence of effects on bees, and are no longer available to amateurs.
Aquatic toxicity. Metaldehyde slug pellets were withdrawn from outdoor sale after concerns about wildlife and water contamination, having been repeatedly detected in drinking water sources.
Health concerns and regulatory review. Approvals expire and must be renewed with current evidence; several were not renewed, and manufacturers frequently choose not to fund the reapproval for a small amateur market.
Cost and market size. Reapproval is expensive, so products disappear commercially as well as regulatorily.
What remains available tends to be: ferric phosphate slug pellets, approved for organic growing; fatty acid and plant oil based insecticides and physical-action products; sulphur-based and a small number of remaining fungicides; and glyphosate-based herbicides, which are permitted while remaining the subject of substantial ongoing debate.
The legal points that matter:
Only use products approved for amateur use, with instructions for the situation and plant. Using a professional product without the required qualification is an offence, as is using anything off-label.
Never use anything on edible crops unless the label specifically permits it for that crop.
Home remedies are not exempt. Applying a substance to control a pest makes it a pesticide, and using unapproved home mixtures is not lawful, however traditional.
Dispose of withdrawn products properly through council hazardous waste, not down a drain.
What the withdrawals have pushed gardeners toward, largely productively: tolerance of some damage; encouraging predators; barriers and physical removal; resistant varieties; and improving growing conditions so plants resist problems.