This is a continuation of my post on Japanese Beetles destroying our bean leaves, so if you missed that post you can check it out here. In talking with other gardeners they’ve noticed an uptick in problems with Japanese Beetles like we have. After some reading at the U of MN Extension website I decided that we could use some organic pest control to bring peace and balance back to the garden. We had large groups of these beetles by our Nanking sour cherry bush, our pole beans, and to a lesser degree in other areas (e.g., a peony died close to where patches of grass were dying and we don’t have a dog). we don’t know if this was specifically from the Japanese Beetle, but we’ve seen quite a few grubs when digging in our yard and when moving plants that haven’t well in certain locations, so I thought this would start to address that problem also.
I anticipate using multiple methods to deal with these pests, and one that I wanted to try was applying beneficial nematodes of the strain that targets these and other problem beetles (Heterorhabditis bacteriophora). Here is a picture of the package of nematodes packed in ice. No, not carbonite. Though, Jabba the Hut does bear a certain resemblance to a garden grub.
I removed the spunge from the clear packet and poured water over it into the bucket. I squeezed the spunge and added more water to the bucket in order to make it less concentrated. You can’t see the millions of nematodes teeming on the spunge, but you follow the steps in faith that they are there. I also rinsed the clear bag to make sure any left in the bag were washed into the bucket also, per the directions.
I don’t have an elegant system for spraying anything on the turf, but I think what I tried should work. We had an excellent amount of rain the night before the application – 2.75 inches. I didn’t have a nozzle to connect to the hose, but I tried two approaches. First I tried hosing areas to get them freshly wet, then sprayed followed by more hosing. This took a while to do, but it was like pre-treating stains for the laundry for the areas in the yard where the bugs hung out the most. Next I tried putting the spray bottle up next to the water stream from the hose to carry the nematodes to the ground. This second approach seemed to work well and sped up the process for general yard coverage.
I hope this application helps control some of our grub issues. For me it’s not a matter of having a sad-looking lawn as much as it is trying to prevent damage to crops and perennials now and next year. Until then, in soil not so far away, there is a turf war between the nematodes and beetle larvae…