Non-poisonous slug control
Robert Hart
It was after an entire generation of seedlings had been wiped out that I decided to make a comprehensive study of the likes, dislikes and habits of my slimy friends. I was determined to get even with them at all costs - except by the use of poisons. In this conservation project, poisons of any kind are taboo, even poisonous plants. Poisoned slugs can lead to poisoned birds, moles and hedgehogs.
'Poisons of any kind are taboo, even poisonous plants. Poisoned slugs can lead to poisoned birds'
Sir Albert Howard, one of the pioneers of the organic movement, regarded pests and disease germs as 'censors' of less-than-perfect health in plants, animals and soils. Any organism in a state of positive health has the ability to resist pests and diseases. At Howard's Indian agricultural research station, his cattle rubbed noses over the fence with cattle suffering from foot-and-mouth disease, and remained unharmed. It is said that a positively healthy appletree can even resist bullfinches. The reason for this is in the immune system, which nature provides to all living organisms, including mankind. Pests, disease germs and viruses are not the basic cause of disease; they are nature's method of destroying unhealthy tissues. They are attracted to acid substances; all organisms in a state of positive health, including soils, are predominantly alkaline.
'All organisms in a state of positive health, including soils, are predominantly alkaline'
There is little doubt that slugs are a symptom of acidity in the soil. Soil on which uncomposted farmyard manure has been spread is a breeding-ground for slugs. Therefore the first line of defence against them is a covering of lime. This not only sweetens the soil but also tickles their sensitive tummies, which they don't like. Wood-ash and soot perform similar functions. Watering the soil with liquid seaweed also has an alkalising effect. Calcified seaweed meal has the additional bonus of tiny shells, which also deter slugs.
Slugs also dislike strong smells. Many aromatic herbs, such as the various mints, tansy and balm, deter slugs and other pests and disease germs from attacking not only themselves but also their plant neighbours. The trouble with planting them between vegetables is that they are extremely invasive; they are as vigorous as the worst weeds.
'A herbal mulch, consisting of sprigs of aromatic plants and conifer twigs, deters slugs and other pests'
The best way to protect vegetable seedlings and transplants, I have discovered, is a herbal mulch, consisting of sprigs of aromatic plants and conifer twigs, which I spread between the rows. This not only deters slugs and other pests, but also screens the young plants from the wind, shades them from excessive sunlight and breaks the force of heavy rain. It also suppresses weeds and improves the soil, keeping it damp and preventing compaction. As it decays it feeds the young plants.
The herbal mulch also has a camouflaging effect. A bed of tender, young greenery can be irresistibly attractive to mischievous birds and mice, but, when surrounded by a many-coloured 'barbed-wire screen', the young plants are less conspicuous.
The final weapon in the campaign against slugs and other pests is constant hoeing. This not only breaks up lumps of earth, under which slugs love to hide, but also, by aerating the soil and removing obstacles to growth including weeds, hastens the young plants' growth. 'Keep them moving' is the watchword. The young plants soon acquire the vigour needed to enable them to resist pests and diseases themselves.
The final tip is, as far as possible, to choose plants with a natural immunity. Greedy slugs love brassicas which are greedy feeders, requiring lots of manure. But more and more members of the chicory-endive family are appearing in seedsmen's catalogues. These are attractive hardy plants with a wide variety of shapes and colours - some even develop red and variegated spears in the autumn - which originate from France and Italy. They are excellent substitutes for brassicas and lettuces throughout the year - and, from my experience, they are almost completely immune to slugs.
Robert Hart, Highwood Hill, Rushbury, near Church Stretton, Shropshire SY6 7DE (tel 06943 342).
Previous / Next / Table of Contents