Grubs in Planters

Asked May 15, 2019, 12:24 AM EDT

Hi, I have some vegetable planters (8' L x 1.5' W x 1' D) that I built a while ago and they needed to be replaced. So, I made these nice cedar raised bed boxes to replace them. The soil is really nice - I've been using and amending this soil for many years, so I really want to keep it for the new raised bed boxes. I took the soil out of the old planters today and one of them had GRUBS! ICK! Lots of them - I found like 30 or 40 but I'm sure there are more, plus possibly eggs. I don't want to get rid of this soil, but I don't want to use any sort of chemicals to get rid of the grubs - I want to keep it safe for growing things we eat. I've searched the web and haven't found any good solutions. Beneficial nematodes are an option but they can take a long time to work. So here's my question --- I have a really big plastic tarp. If I spread the soil out on the tarp and let it bake in our Arizona sun for a couple of days, could that potentially kill the grubs and their eggs? I know it will probably also kill other beneficial things in the soil, but I think I can reestablish that with things like fish fertilizer. What do you think? Thanks for any help or advice :) Chris

Maricopa County Arizona raised bed gardening

1 Response

Thank you for your question, Chris. The general rule about insect management is first to determine what the insect is. I do not recognize these, the insect may have been living quite compatibly there for years,, and you would unnecessarily be killing it just for the “ick” reason. I suggest you contact your county Extension office for advice before exterminating them. Here is their webpage: Good luck!