It’s that time of year again. By now you should be dealing with various garden and landscape pests. They take many forms: some are invasive plants which will continue to proliferate as a result of our recent abundant rain. Some will be weeds — defined as plants which grow in places you don’t want them (despite the fact that some can be edible like purslane and dandelion). Other pests are downright annoying and even life threatening like mosquitoes. And then there are the real invaders which go after your ornamentals and veggies: think Japanese beetles and cabbage moth caterpillars. What can a gardener do?
Considering they all have a place in the master plan, let’s step back and approach these issues like stewards of the land: always be conservative and use a classic Integrated Pest Management (IPM) approach. That means you need to first identify and know the enemy; second, decide if you need to take any action (the effective time to fight back may be long gone); third, decide the least toxic control option; and fourth, use the big guns of pesticides or herbicides only if you can’t tolerate a little cosmetic damage or if the invader will continue the assault.
Considering all that, veggie gardeners in the organic Fairfield County (CT) Master Gardener Demonstration Garden have turned to a DIY Insect Netting Barrier to protect their brassicas this season . Row covers are one approach they could use to keep cabbage moth caterpillars from eating holes in cabbages and kales, but this is a demonstration garden which is open to the public and these master gardeners wanted to be able to have this crop clearly visible. In past years, the gardeners had engaged in hand picking and frequent spraying of Bacillus thuringiensis var. kurstaki (Btk) to control this insect. BTK is an organic treatment, derived from a naturally occurring soil bacteria. It controls most leaf eating caterpillars so it is ideal for this pest. It’s totally harmless to people, pets, birds, honeybees or beneficial insects. Remember, however, that butterflies come from caterpillars so one needs to be mindful of that when using BTK. As for how it works, the caterpillars must ingest it (it is a stomach poison) which means you must apply it to the caterpillar itself – not simply the foliage when you don’t see the caterpillar. But this caterpillar is a master of disguise . If you have the holes, you most likely have the caterpillar — trust me.
But the constant spraying and hand picking for this large garden consumed a huge amount of time. Since no pollinators are necessary for brassicas, the gardeners decided to use the netting this season to fully protect the crop. Flea beetles were dispensed with using sticky cards early on and the netting went up. It’s not too pretty, but it sure is functional. The crop is clean as a whistle and the netting will get better looking as the gardeners refine the construction during this first season.
The gardeners are now free to use their time planting up the rest of the garden and harvesting the early crops for local food banks and shelters. The expected yield will be closer to 100% than the 60% of prior years, a real plus no matter how you look at it.
Gardeners 1, insects 0!
By Lorraine Ballato