Are caterpillars damaging your plants? If you’re having a tug-of-war with caterpillars over who gets a fair share of food from your edible crops, you’ll know how frustrating it can be to come off second best! As mentioned in Coping with Caterpillars – Part 1, the first step is observation and diagnosis to ‘know thy enemy’.
13 Sneaky Strategies to Manage Caterpillars
The next step is to try a combination of organic solutions to prevent caterpillars from causing damage as well as minimising the impact. These are some effective strategies you can use in your garden.
1. Prevention is Better than Cure
Exclusion is a simple but effective method of keeping moth and butterfly mothers at bay. If the butterflies and moths can’t make contact with your plants to lay eggs, an investment in protective netting may be a simple and sustainable solution. Preventing access to your crops with vegetable nets and crop covers stops caterpillars from damaging your edibles.
There are both commerical and DIY options for excluding pest insects. Fine mesh netting (even old net curtains), bags or sleeves, floating row covers and shade cloth stop butterfly mummies starting their families in your vegetable patch ‘maternity ward’.
2. Companion Planting
I use nasturtiums, flowers and highly scented herbs to draw the attention of these mummies ready to unload their baby bundles away from the edible crops I want to protect! I’ve found this strategy to be extremely effective, although I do use it in conjunction with other techniques on this list.
Nasturtiums in particular work well as a ‘catch crop’ or sacrificial plant for mummy white cabbage butterflies to lay their eggs on without destroying my food crops. Gather up the affected leaves and feed to your local birds or chickens.
3. Plant Diversity
The more plant species you grow, the less likely for pests to attack. Each plant secretes its own unique odour or ‘signature smell’ that helps attract (or repel) butterflies and moths (as well as other insects). The more diverse your garden is, the more mixed and confusing scent signals it sends to egg-laying adult moths and butterflies and using this strategy has considerably reduced caterpillar damage in my garden.
I’ve planted tall skinny spring onions, nasturtiums, basil, dill, sage and marigolds very effectively with broccoli, kale, cabbage and cauliflower and found I had no caterpillar problems at all. The brassica crops are completely left alone.
4. Confuse Them and Lose Them
Try planting your vegetable garden with different shaped edible plants, rather than rows of the same variety. This is another way to confuse the butterfly and moth mummies, so they find it harder to locate their food source. i.e. plant ‘diversity’.
A cottage garden design helps minimise damage rather than planting in rows that all look the same. You can still design an attractive kitchen garden by repeating your plantings at regular intervals.
5. Early Detection
Moth eggs won’t eat your plants, however when they hatch the baby caterpillar mouths will soon eat small holes. As they grow, so does their appetite and the more of your plants they consume.
Just like teenagers who open the fridge constantly looking for food, a voracious army of caterpillars in your garden will seriously deplete your crop in no time unless you ‘close the fridge door’.
6. Birth control
This is a bit like playing ‘hide and seek’ as a detective in your garden. It’s a great game for kids playing the role of Pest Patroller.
Look for ‘clues’ like holes in your leaves and telltale green droppings (frass) to detect their location. Use a magnifying glass if you have one.
Tip: If you can’t bend over easily, glue a small mirror onto the end of a long lightweight stake and position under the leaves to check the presence of suspects.
Smearing a pile of tiny eggs with your finger onto the leaves is much easier and less time consuming than looking under every leaf, stem and fruit for mature culprits who are already wriggling and eating their way to veggie heaven.
“It is by studying little things that we attain the great art of having as little misery and as much happiness as possible.” – Samuel Johnson
7. Green Thumb
I often wonder where this term originated, because my take on having a ‘green thumb’ is not so much about being an experienced gardener, but rather using this appendage for pest management purposes and the resulting green colour that results! This simple but effective extermination system of hand removing caterpillars on the leaves where you find them has several benefits (unless you’re squeamish!)
I think of this strategy a bit like a mum about to give birth, driving into the car park of her local hospital where she’s been many times before (perhaps with previous births) and seeing multiple fatalities at the front entrance. If it was me, I’d turn my car around and have my baby at another hospital! So I try to send a message to the butterfly mummies that are thinking of stopping by my plant ‘nursery’ to drop off more baby bundles, to think twice and find another ward where there are less infant mortalities. So far, this seems to work well … unless it rains.
8. Nature’s Nets
I used to wipe out spider webs regularly in my garden until I realised the amazing role they play in pest management. Spiders have a huge appetite for insects and I’ve often watched them spin a web right beside plants that are being attacked by grasshoppers. They seem to ‘set up house’ right where there’s a free source of food. Sure enough, the next day I see grasshoppers, moths and other pest insects caught and wrapped in the web. Leaving ‘nature’s nets’ in place will help keep your pest insect problems in balance.
9. ‘Bed and Board’ for Birds
If you create an environment to attract birds to your garden, you’ll also find they hang around and take care of your pests. Caterpillars and bugs are an easy pick for any sharp-eyed bird. A diversity of trees and shrubs will provide a safe habitat for small birds to roost and nest. Plant nectar-rich flowers to provide food for honey-eaters like cosmos and sunflowers.
“For every creature you have in excessive numbers, there is at least one and probably many other creatures who would be delighted to relieve you of the excess, for free! In natural systems everything, alive or dead, is food.” – Linda Woodrow, ‘The Permaculture Home Garden’
10. Predator Perks
You can also encourage natural enemies of pests (beneficial predator insects) to assist you. In fact, they’ll take care of pests for free, so no need for time-consuming and expensive sprays and remedies.
Some wasp species paralyse their prey (including the cabbage white butterfly caterpillars) by parasitizing (injecting their eggs) through a vulnerable body part in their unsuspecting victim, as it crawls along a leaf. You can see the caterpillar below on a broccoli leaf.
Tip: If you notice the caterpillars on your vegetables, but they are not moving and may be a darker colour or have a papery appearance, then it’s likely your wasp ‘cavalry’ have been and gone and your pests are being dealt with nature’s way. If you think you’re up for it, watch this gory story to see the amazing way nature works in National Geographic’s video on Body Invaders.
11. Maintain Pest to Predator Balance
For a healthy organic garden where the pest to predator ratio is in balance, I feel it’s important not to over-react to a perceived ‘problem’. By having a small number of pests (whether they be a few caterpillars, aphids or grasshoppers), your garden will automatically attract these insect’s natural predators who are looking for a regular food source.
I have realised that if you totally remove their tucker, the ‘good guys’ will starve … then if you need their assistance when you have a real pest outbreak, it may take a few days for the beneficials to notice the table is set at your place for some fine dining and come to the rescue!
12. Plant ‘Good Bug‘ Tucker
If you are committed to a non-chemical approach to your pest management, provide food (nectar and pollen) and habitat (a ‘bed’ to play happy families and reproduce!) for your beneficial insects. This will encourage them to take up residence at your place.
I plant a Good Bug Mix of annual and perennial flowers and herbs to attract the good bugs to my garden so I can have plenty of happy free workers doing what they love best. Even if you haven’t got a pest ‘problem’ the goodies will be on hand for when you do! This video gives you some examples of useful plants.
“My advice is: consider what level of damage you can live with and if a few holey leaves won’t kill you, perhaps let nature take care of its own.”
13. Catch and Trap
While spider webs play a role in capturing some insects on your behalf, you can also be more proactive. If cabbage white butterflies are very active in your garden for instance, you can use a butterfly net to capture adults to stop them laying eggs and reproducing. Children will be happy to do play a ‘catch the butterfly game’ for you while exercising outdoors!
Sticky yellow traps can also be used selectively to attract and capture small moths at night. You can purchase these or make your own.
Affiliate Links: Your support of this site is appreciated!
You may need to use several strategies to reduce the damage caterpillars and other pest insects have in your garden. I hope these organic solutions and ideas will help swing the balance back in your favour.
Related articles: Coping with Caterpillars – Part 1
© Copyright Anne Gibson, The Micro Gardener 2010 – https://www.themicrogardener.com. All rights reserved.