Q: How do I identify and control large cabbage white butterfly?
Tortoiseshells, Red Admirals and Brimstones are all lovey, flitting about butterflies. Ahh, so nice. Large cabbage whites, however, are the number one enemy of all cabbage growers or, in fact, growers of cauliflowers, sprouts and any veg belonging to the brassica family. Healthy plants can be stripped of all their leaf tissue within days of a bad infestation.
What they look like:
The large cabbage white butterflies are large and white (it’s tricky this gardening stuff you know!) Their eggs are orange-yellow and any resultant caterpillars are fat and healthy at the cost of your greens. They leave the garden a few days later as large white, butterflies, which then go on to lay eggs somewhere else. You have a duty to your brassicas and others to sort this pest out from the start.
How to sort:
- Net your brassica plants to stop the butterflies even getting to the leaves. Peg it down well as, if they slip in underneath, they will wreak havoc.
- Get into the routine of checking your plants - underneath the leaves and especially the ones tucked out of immediate sight. Check daily for the small, yellowy-orange eggs. Squash them or wash them. It’s a messy job but if you miss any they will quickly grow.
- You can spray if you want (your choice!) and we have suitable pesticides available.
- If you miss the eggs and they hatch into caterpillars (fat, hairy, yellow and black), there are biological controls to spray onto the leaves.
- Birds do pick them off but never in suitable numbers to reduce damage (you can collect the caterpillars and put them on the bird table if you want though).
- There is evidence if you mix your brassicas in with other crops ie don’t grow one big patch of cabbages, the butterflies actually don’t sense them as well and fly off doing their egg laying business elsewhere. It’s worth a go.
You’ve got to act quickly to stop this nasty devastating your brassicas.