How to Get Rid of Grubs in Your Compost Pile

Q. I started a Mulch bin about 10 yr. ago. It is about 4ft. by 6 ft. on the ground. Today when I went to get mulch for my vegetable garden and found a 1/2 dozen Grubs. How do I get rid of the grub and keep the worms?

A. First of I would like to refer you to a pretty extensive discussion I posted on my blog regarding composts and grubs in the compost.

http://xtremehorticulture.blogspot.com/2012/07/grubs-in-container-of-garden-soil.html

Grubs from compost pile

 Secondly, we have to remember that these grubs, like earthworms, are decomposers... they are taking raw products from your compost and helping to convert them into a soil amendment of very high quality through their gut. But we also know that these are potentially problem bugs when they mature so as you already identified it might not be a good idea to cultivate them.

If it were me, the compost pile needs to be turned regularly to aerate it so it does not get anaerobic or it will get all sorts of problems. So if you are turning your compost pile then expose these grubs for the birds. Have you ever seen birds follow a tractor that is cultivating a field? the birds know that during cultivation all sorts of goodies are exposed and looking for a free lunch.

The other problem you may encounter (I am not sure because it is not clear) is that your compost pile might be in some location where the birds cannot get to it such as a barrel composter or the like. One advantage that worms have over grubs is their ability to move faster than grubs can. If the soil is starting to heat up, they will go deeper quite quickly while the grubs cannot. So another alternative is to cover the compost with clear plastic and heat the upper layers of the compost but allow it to be deep enough so the worms can escape. Keep it at 165F for at least 30 minutes and let the grubs cook and then let it cool down. The earthworms will again migrate back up to the upper surfaces or through the compost. A third way is to remove the worms. Heat up the compost with solar energy (clear plastic again) and re-introduce worms after it has cooled.

I hope this helps.