We try to be as environmentally-friendly as possible and use nematodes and traps where possible. Unfortunately, sometimes, conditions dictate that slugs and snails get out of hand.
From a zoo gardener
A: I am delighted you already use nematodes and traps but I agree there are occasions when it is necessary for something fast-acting to bring numbers back under control. Did you know a small slug can eat the equivalent of its weight in a day?
Metaldehyde is a well-known molluscicide but there is a lot of controversy surrounding its use because it is dangerous to game, wild birds and animals - although used in slug and snail control it does include a proprietary dog and cat deterrent. Metaldehyde is also harmful to aquatic life. There are alternatives such as aluminium sulphate and ferric phosphate.
Aluminium sulphate is available as 6X Slug Killer from Organic Concentrates, B&Q Contact Slug Killer, Doff Slug Attack and Septico Slug Killer from Growing Success. It is a granular product that works on contact with the slug or snails and can be used around edible and non-edible plants.
The other active ingredient, ferric phosphate, is available in B&Q Advanced Slug Killer, Doff Super Slug Killer, Ferramol Slug Killer and Sluxx from Certis, Growing Success Advanced Slug Killer, Slug & Snail Control and Slug & Snail Bait from Bayer CropScience and Slug Death XL by Vitax.
Last year Certis introduced Ferramol Max, a slug pellet formulation for the ornamental and amenity sectors that offers a lower-cost but highly-effective slug control solution. It is a more concentrated, three per cent ferric phosphate formulation. The original Ferramol is only one per cent.
Ferric phosphate has a good environmental profile in terms of low toxicity to all non-target organisms and it will eventually degrade into naturally-occurring nutrients. For professional use, Ferramol Max is available in 7kg resealable packs.
In some situations the use of copper barrier tape that emits a tiny electrical charge may be appropriate. Vitax offers such a product. The company also supplies Slug Off, a natural ingredient that forms a non-toxic slug and snail control barrier.
Remember: use plant protection products safely. Always read the label and product information before you use them.
Sally Drury has been reporting on product developments and testing kit for 28 years. The advice given in this helpline is independent.
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