Slugs and snails, words to bring fear to any gardener’s heart! It’s been a good year in the endless slug war so far but warm wet weather is ideal for the slimy devils. What to do?
There are lots of remedies and natural controls advocated for keeping plants safe from slugs and snails but not all of them actually work. Back in 2019 the RHS undertook a study of five popular organic home slug control methods and found them to not be effective.
Copper tape, horticultural grit, pine bark mulch, wool pellets and egg shells were all shown to make no difference when applied to lettuce, with gastropods inflicting the same damage to those treated with the remedies as without.
Copper tape is supposed to create a static electricity barrier that the slug won’t cross but as the photo shows, they’re not that bothered by it. Sadly the same goes for the other barrier methods in the list above.
Well the people at Envii make an organic slug control method called Feed & Fortify that uses diatomaceous earth to naturally protect plants from slugs, snails and other small pests. It also contains iron silicates to improve soil fertility and maximise plant growth.
They decided to replicate the RHS study on the slug barriers and also put their Feed & Fortify to the test. The video answers the ‘does it work?’ question (spoiler alert!) – it works.
The feed part of the name – the Iron Silicates – might benefit from a little explanation.
Iron for Plants
Iron is an important micro-nutrient for plants. A sort of plant vitamin. They only need a very small amount, but that small amount is crucial to healthy growth. Iron is utilised in the production of chlorophyll which is the engine that converts carbon dioxide to carbon and oxygen and feeds the plant as well as giving it the green colour.
A lack of iron will show itself as yellowing on the leaves and a sickly plant.
Silicon is a common element that aids plant growth and quality, photosynthesis, transpiration and enhances plant resistance to stresses such as drought. (see this article from Greenhouse Management) Plants grown in commercial potting composts – patio pots, hanging baskets etc. – are most likely to be in need of supplemental silicon.
Natural Slug and Snail Controls
Seeing is believing and the film below shows how the slugs react when faced with different barrier methods.