Question
I live in New Zealand and I have been getting some type of worm which lives inside the cabbage as it grows. It looks a bit like what we call a tiger worm or some sort of compost or earthworm.
I do use large amounts of organic matter in the garden. It is very annoying to find these in the cabbage when preparing it for dinner.
Can you suggest a way of preventing this?
Many thanks.


Answer
The best way to prevent worms is to stop the coddling moths from laying their eggs.  I use reemay, otherwise known as row covers, over my plants.  This product is made from a fleece-like material similar to curtain sheers.  It is lightweight and is porous, which allows in water and sunlight.  For fruit-bearing vegetables, it should be lifted once the plant blossoms for proper pollination.

To control the cabbage worms after they hatch, I would recommend a highly effective organic insecticide called BT, short for Bacillus thuringiensis.  It is more commonly sold under the brand names Dipel or MVP. It is a dust that is non-toxic to humans and beneficials but highly effective against caterpillars and cabbage worms that are the resulting larvae of cabbage moths.  These products can also be purchased through on-line catalogs such as Gardens Alive or locally at many garden centers.

One other preventive measure you can take besides covering the plants with reemay is to plant dill near your cabbage and broccoli plants.  The cabbage moth that lays the eggs is
deterred by the smell of dill.  That's what makes dill such a great companion plant for brassicas.

I hope this answered your question.  Please write again if I can ever be of assistance.

Regards,

Mike