Check beneath soil to see if you have grub worms
If you have tried more water, different or more fertilizer, iron or soil acidifiers, but still can’t get your tree or shrub to look healthy, it might be grub worms. They are the larvae of the May and June beetles, which are the large brown beetles that hovered around your yard right before sunset. You probably have inadvertently played tennis with them or they may have buzzed around your hair this past spring. Very pesky varmints! If these pests were present in your yard a few months ago, you probably have grub worms feasting on your lawn, tree and shrub roots right now.
They will show up on your lawn as brown patches that can be lifted up like a piece of carpet. They can weaken or stress new-planted trees or shrubs by chewing up newly formed roots. They can be the size of your pinkie and they can wreak havoc in your landscape.
Fortunately there are some beneficial nematodes that are a natural and organic way to control grub worms. Although they might be a bit tricky to apply, this is a great way to be rid of these critters, especially if you have pets and/or children in the garden. The upside to this method is of course it is organic and will also kill a variety of other harmful soil creatures without hurting earth worms. The downside is that it is more expensive and covers a smaller area, and may take a bit longer to work.
Of course there are granular and liquid forms of grub control. They are relatively safe to use but do not fall under the “organic” line of pesticides. Both list that it is safe to reenter treated areas after the insecticide has thoroughly dried. The upside is this method works immediately, with the exception of the largest of the grub worms, and covers larger areas for the money spent. The downside is that it may harm earthworms as well as other beneficial organisms. As always please read and follow all of the directions on the label of any products you use.
So if you can’t figure out why your plants are not thriving, dig deeper into the soil. There is no mistaking these unsightly creatures. They have an offwhite body with a dark brown head. Skunks and birds love to feast on these. By the way, getting rid of these grubs may also get rid of your skunks, if you have them, of course.
Gary Guzman is the owner of Color Your World LLC, Guzman’s Greenhouse LLC nurseries and is a native Las Crucen with more than 30 years in the horticultural field.