Slugs and snails are everywhere at this time of year, especially with all this wet weather, so this week I thought we would take a look at them. We’ll cover how they affect your garden, where they like to hang out and how to control them in an organic way.
Many people look at these creatures simply as annoying pests that destroy their vegetables, however, I believe it is better to look at them in a more rounded way – as I look at any other pest. They are part of the cycle of nature and they just happen to like your veggies – as well they should, they’re delish!
So what exactly are we dealing with here…?
Did you know there are around 1,400 varieties of slugs and snails in New Zealand?? It’s not surprising then that some get into our gardens!!
The largest snails can grow up to 10cm across! They move around on a flat muscular foot and they eat by using a tongue-like organ called a radula, which is covered with rows of teeth. Slugs and snails have both male and female sex organs and one or two pairs of tentacles on their heads, the larger of which usually has eyes at the end.
Where do slugs and snails hang out?
Most snails live on the ground in the leaf litter that has fallen; under your mulch or around dark damp places, where they are unseen. The giant snails live mostly in Northland and grow up to 10 cm. These snails come out in the dark of the night to eat slugs and worms.
There are about 30 odd native species of slugs, and they eat algae, fungi, and tiny organisms that live on plants. However, most of the slugs and snails that eat your garden are not native to New Zealand and have travelled here from other countries! Like most other introduced pests in New Zealand, they are very destructive to the home and the commercial gardener.
Remember – slugs and snails are in our gardens all year round – it is just in winter and spring they do the most damage because of the climate. During the warmth of the summer sun, they tend to stay in dark, damp places.
They come out after dark. This time of year, I have noticed they start appearing after 8pm and in the spring, it is more like 10pm.
How do slugs and snails affect my garden?
Slugs and snails feed on fruits, vegetables, the soft stems of plants as well as the leaf tissue. They are especially partial to new transplants, as these are soft and tasty to them. That is why a newly planted bed can disappear overnight, causing much despair to a loving gardener the following morning!
Plants that have many leaves altogether like the brassica family, lettuce and spinach seem to attract a lot more slugs and snails. In my experience, this is because these plants offer dark and cool shelter for the slugs and snails during the day and then, at night, they don’t have to travel far for their food. Pretty smart really!
If you are growing your winter broccoli, cauliflower, lettuce and spinach, pop out to the garden now and gently peel the leaves back during the day and look closely at where the leaves attach to the stem. You will more than likely find the little creatures asleep there. You can also look for a poo trail, as they leave a trail behind them when they munch your leaves…!
So what are the organic ways to control slugs and snails?
The tiger slug was introduced into New Zealand from Europe. I find these slugs a beneficial pest, as they will eat other smaller slugs. They will still eat your veggies (!) but they can be a natural control for smaller, more vulnerable slugs.
Tiger slug
One of the most effective controls I have found is to snap the lower leaves off of your brassicas and place them around new seedlings in a circle. The slugs and snails would rather eat what is in front of them than use the energy to travel up a plant. In the morning, look under these leaves that you have placed on the soil and remove any that are present.
Beer traps are another goodie. Place shallow lids on your soil, pushing them down slightly so they are at soil level and put some cheap beer in them. No need to waste the good stuff! They love this and will flock to the beer and drown while drinking. Make sure you clear them out every couple of days.
Regularly check all the dark, damp places around your growing bed, as they will be asleep in the day and are easy to see. They like to be under lids, wood, mulch and the corners of your raised beds.
Hedgehogs and birds are natural predators, so we welcome them wholeheartedly into our gardens at this time of year. Plenty to go round, and no fruit to protect from the birds!
I also recommend feeding your slugs and snails away from the bed with old brassica leaves in a pile. I tend to put my pile at least 3 metres away from my bed and they love it.
As an organic gardener, I must advise you…
SNAIL AND SLUG BAIT – NO NO NO NO NO NO NO!!!!!!!
I have recently encountered several gardeners who profess to have an organic garden, but yet they use snail bait! Unfortunately, this is misguided. Just to see the bright blue colour of the bait, you know it is toxic!
Snail bait contains metaldehyde which breaks down into our water ways, and is highly toxic to animals. This bait can be attractive to animals as it is often mixed with bran, molasses, soya beans and rice to bulk it out. Please, please try the methods above and avoid bait at all costs.
I adamantly believe with all my gardening passion and 30 years of experience that chemicals have absolutely no place in our soil, or our eco-system. We ingest what we put out into the world, as we are all one. These organic methods are truly effective, and I challenge you to try them and feedback if they are not…!
Check your garden out tonight for these little creatures, try some of my suggested methods and let me know how you get on.
Happy gardening!
Love your emails. What is your thoughts on using copper pipe around the edge of the raised garden? Does that stop them?
Thanks for your question Simon! I have personally had mixed results – approximately 60% success. I will do more experiments and report back!