Grubs

As you can imagine, due to the lack of blog posts, I am building up quite a backlog of items to talk about. Today's topic -- grubs -- is not very exciting, but has been a crucial element in the success of my garden, both vegetable and ornamental. I had grubs in my gardens in Connecticut and in South Carolina. The grubs were small, and there weren't enough of them to do much harm to the garden. We had lots of Japanese beetles during the summer, and I always assumed the grubs were the larval stage of the Japanese beetles. Our lawn in South Carolina had lots of wild violets in it, and I noticed that the grubs seemed to cluster around the violet roots. So they weren't really a problem.

Not so in Costa Rica. The grubs here are the larva of the May beetle. They are big, and they are everywhere. Seventy percent of my first planting of corn was wiped out by grubs. They seemed to be everywhere -- big fat grubs (at least twice as big as the Japanese beetle grubs) munching on the roots of grass, shurbs, trees, and vegetables. When I dug in the soil, almost every shovelful of soil had a grub squirming in it. Yikes!!!

In desperation, I contacted Ed Burkhardt, who writes a gardening column for the Tico Times newspaper. Ed made a vague reference to a type of nematode that did not harm the plants, but loved to munch on grubs.

I did a little research on the internet and then contacted the Buglogical Control Systems in Tucson, Arizona. They assured me that their Heterohabditis bacteriophora nematodes would do the job, and would continue to work for me for five years or more. So I bought 50 million of them (enough to treat one acre). They overnighted them to a friend in Clemson, who put them in his refrigerator, and came to Costa Rica the next day with the nematodes packed in his checked bag.

First thing the next morning I sprayed them on the grass and soil around the property. That afternoon we got a soaking rain, which was perfect to wash the nematodes down into the soil.

I saw grubs for a couple of months after that when I was digging in the dirt, but far fewer than before. Now it is a rare occasion to find a grub anymore. And what a relief it is.

Happy gardening!