Night Crawler Worms are Ruining My Lawn

Answer by WR: Since this is perhaps more of a gardening issue than a composting issue, be sure to contact the Master Gardeners via the link I gave below.  I think you'll get some good information from them.  Note that, as mentioned at the bottom of the page about the MG hotline, they are in the off season and most of their questions are handled through their Ask An Expert page: https://abqmastergardeners.org/public-ask-an-expert 

Answer by JH: My thoughts: being from Ohio it was common to see lots of earthworms on the sidewalks after a drenching rain because they can’t tolerate the saturated soil. I suspect that perhaps birds are feasting on them which might partially explain the many holes. The good news is that those healthy earthworms are aerating the soil so you don’t want to use chemicals to remove them. They are beneficial.

Answer by RB: In doing a little research, I discovered that nightcrawlers can be problematic if there are enough of them, because of the hard lumps their castings make  in the lawn.  They do not, however, kill the grass—as Jana pointed out they aerate and and and add nutrients to the soil, so chemicals should not be used. The ideal solution (in my opinion) would be to rent chickens to eat up your worms.  Unfortunately I just checked the Rent the Chicken website and they don’t include NM in their service so that’s not an option unless you know someone with chickens and a portable coop (called a tractor) that would rent you the birds for a month or two. I suspect ripping out the lawn might only be a temporary fix since many of the worm eggs might be left behind. Sorry not to be more helpful!

Response from original questioner: Thank you all so very much for your investigative work and for sharing your information with me. I love the idea of borrowing our next-door neighbors chickens, so I will look into that. The latest picture I sent with the dirt mounds, are not from birds trying to get to the worms. Those are the mounds of dirt/worm castings that we are trying to get rid of. It has been really funny to watch robins attempt to eat these worms. A couple of years ago we had lots of robins come to the yard and work really hard to get these worms out of the ground. When crawling on the ground, they are about 5 inches long but as the worm tries to stretch it to get it out of the ground, it becomes much longer. For the last couple of years, the robins seem to have given up. I’ve also tried feeding them to my turtles, but they also will not eat them. I assume it’s the diameter of the worm, the tough skin or the fact that the worm is flopping around hitting the turtle in the head while the turtle is trying to bite it. I wish that we had just the garden variety earthworms because we would not try to get rid of them. These nightcrawlers have become very destructive. You have all been very helpful and very gracious to take the time to reply. I will leave you with one last set of pictures comparing a handful of  nightcrawlers in comparison to an earthworm.

Response by WR: Hey all, is it possible that these are "Jumping Worms", an invasive species of earthworms from Asia? Do a web search for New Mexico Jumping Worms.  I couldn't find anything to verify that they made their way to New Mexico except the opening AI that actually said they are in New Mexico, but I don't necessarily trust the AI.

Response by JH: If they are jumping worms, they have cocoons which would be evident in the top 2 inches of soil and they SHOULD NOT be fed to chickens.

Response by original questioner: You guys are wonderful!! We are really appreciating all of your suggestions and ideas!  Please keep them coming, even if you happen to hear something in the future—we will plan on dying in this house that we've lived in for 35 years. Today's shout out goes to WR and KJ, for the reference to "jumping worms"!!  Fortunately, we don't have that type of worm, but we started looking for info about them on-line and found an interesting YouTube video (https://www.youtube.com/watch?v=0bFl6Pw6nzQ) featuring a man from University of Wisconsin-Madison who talks about them. The best part of the video was his suggestion at the end about using ground mustard mixed with water to encourage the worms to come out of the ground. We tried it yesterday, late afternoon and it worked!! It was amazing how quickly the devils came out—we had 16 in about 5 minutes. Of course it was only an area about 12" X 12", so it may not be feasible for the entire yard, but it was shocking—and GROSS. Also, we learned that before walking on different grass/dirt areas, we are all supposed to rinse off the bottoms of our shoes because even by being in our "worm yard", we can spread them to the front yard—probably true for the lawn mower, but how realistic is that? This is a great example of why we keep reaching to people (I'll be emailing the man in Wisconsin next) and really appreciate every suggestion and idea. We live in the area of Menaul and Tramway, so if you'd like to come by and see for yourself what we're talking about, let me know!

Response a few weeks later by WR: I was wondering if you've learned anything new about these mysterious worms. Were you able to find out any information from the Master Gardeners.  Sure hope you have had some success figuring out what best to do.

Response by original questioner: Thank you for remembering us! What we have determined is that they are very healthy Night Crawlers, not the Jumping Worms. Did you get the photos I sent last month? Yuck! Through a series of conversations with people we stumbled upon a YouTube video of Inside Edition three years ago, with an interview with Bradley Herrick at a Wisconsin university about the Jumping Worms. I wrote to him but never heard back, so he may not be at the university anymore. In the interview he had a great suggestion of using powdered mustard mixed with water to draw the worms out of the ground. We tried, even though it isn't feasible for such a large area, but it really worked!! We got 16 worms in 5 minutes in an area 12" X 12"!!! We also reached out to Steve Churchill of the Urban Worm Company in PA and he was nice to reply but had to clue how to get rid of them.  At this point we are considering tearing out the Blue Grass, let the ground sit for a year or two and hope that the worms will die with no water and then put in Bermuda grass or some other type of grass that will take far less water. We have learned that they like just the right amount of water, but not too much and will die without any water. Fingers crossed!! We are taking all suggestions/ideas/thoughts so please keep us in mind as you are talking to people! We sure appreciate your help!

Response by WR:  Thanks for getting back to us. I'd be very curious what our local Master Gardeners would know about all this.  Also perhaps the county extension agent.  It's possible you could ask the Master Gardeners or the Bernalillo County Extension Service for a home visit. You are right, bluegrass takes a lot of water and is not great for our climate.  You didn't ask our advice about the following so please feel free to ignore (!), but I can't help jumping in: If I were you I'd think twice before putting in Bermuda Grass. It spreads into flower and garden beds, etc. and once established is pretty much impossible to control. (Believe me, I know -- I bought a house with large Bermuda Grass lawns 30 years ago and am still dealing with it.) The Master Gardeners could recommend a good grass to plant here in Albuquerque. Or have you considered xeriscape?  Not just rocks and cactus but native flowers, native grass, etc. https://www.505outside.com/wp-content/uploads/2020/08/XeriscapeHowTo-2020_06122020.pdf

I'm still very curious about those worms.  Please do let us know if you learn more about them.

Response by JH: That sounds like a possible solution. However, as a former master gardener I would not recommend bermuda grass as it is an invasive species. Good options for turf grass here are blue grama and buffalo grass. I have seen beautiful lawns sown from blue grama seed. Requires plenty of water to become established but then does not need much and rarely requires mowing. The nurseries that sell these seeds can explain how and when to seed.

Response by original questioner: Thank you so much! Don't worry about sending advice—we love it! We put Blue Grass in 35 years ago when temps were cooler in the summer and water was more plentiful. It has looked amazing, thanks to my husband's care for 33 of those years, until the worms took over. We didn't know that Bermuda was invasive, so thank you for that tidbit. Yes, we did try to figure out some sort of Xeriscape but we still have grandkids who play on the lawn, and we enjoy setting up outdoors with the grass to entertain. We will definitely look into blue grama and buffalo grasses. Thank you very much for the suggestions about a home visit also—I'll check into that.

Response by WR: If/when you take out your bluegrass and put in something like blue gramma, you can probably take advantage of this rebate from the County Water Utility Authority: https://www.505outside.com/residential-desert-friendly-conversion-rebates-xeriscape-conversion/

Response by original questioner: Thank you! We get these newsletters but hadn't paid much attention since we weren't planning on doing any landscaping. We really appreciate you noticing this rebate and bringing it to our attention.