War of the Worms:
Destructive Wrigglers Invade Discovery Bay Garden
Editors Note: Long-time gardener and Discovery Bay resident Bonnie Broders contacted the Free Press in an effort to alert others in the county to a devastating worm infestation that she believes came from packaged organic potting soil purchased locally. She says that unlike conventional earthworms, these worms destroy plants and travel quickly. They multiply exponentially in a short time and exhibit very erratic behavior. The invasive worms have killed thousands of dollars worth of plants on her property and the effort to eradicate them is costing many thousands more. Bonnie cannot prove definitively now that this infestation came from the bagged soil because once the problem started, she destroyed the remaining soil. But circumstantial evidence is significant.
We have asked Bonnie to present her story in her own words. Have any readers had a similar experience? Please share feedback if you can contribute to this conversation.
————————————-
Last fall at the end of September, we had the first rains after a very warm fall. Each evening around 9 o’clock I would go out with a flashlight to capture the tiny slugs that were making holes in some of my greens.
The third night as I walked into my garden, I saw a huge worm migration of thousands of worms. They were traveling quickly on the ground and even climbing up my raised covered beds. I salted them all. They did not look like our normal worms, but were smaller and more slender and they moved like snakes. They were twisting up out of the soil and jumping around like crazy. The creepy worms gave me nightmares for many nights.
After researching bad worms on the internet the following night, several family members came out to the garden to look for the worms. A bag of potting soil left over from a local purchase of 20 bags was at the epicenter, right in the middle of the infestation.
In that area of the garden, I had difficulty planting a late summer crop as the leaf lettuce and arugula seeds would not come up. I kept buying more seeds and re-planting, at least four times, without any success. When we dug in that area, there were over 50 worms in one square foot. In other words, there were thousands and thousands of worms in one corner of my garden, radiating out from the bag of potting soil, which also had worms coming out of it.
[Note: This video was taken in cooler weather when worms are less active, whereas the author says, “When the weather was warm last September, the worms were disgustingly and disturbingly active.”]
We used about eighteen 50-pound bags of salt in that area to kill the worms. They were adult worms with the obvious egg sac around their body. We started tearing up all the vegetables left in the garden, like the broccoli and cauliflower and brussels sprouts and onions. We discovered worms around the roots of all the vegetables except the onions. It looked like the worms were eating the small hairs off of the vegetables, and the plants weren’t thriving. Later I would find out that they ate the root hairs off of all my blueberry plants in the garden, too.
It was obvious that the worm migration centered around this bag of potting soil with worms still in the bag. We burned the bag of soil and all the plants in the garden, and all the wooden raised bed boards and stakes.
Dismantling garden structures and burning infested materials.
At this point, we didn’t know how far the worm infestation would go, but we knew it had to have started from this bag of potting soil. Bad news is I had already spread 19 other bags of potting soil around my yard in various operations.
The Mustard Test and Seed Meal
I had six raised beds where I would grow lettuce above the ground to keep the slugs out. Each raised bed contained hundreds of worms. I learned from research on the internet that a person can look for bad worms by mixing powdered mustard with water and pouring it on the soil. That brings the worms up to the surface so you can see if you have any.
I had also used the potting soil in four areas where I plant annuals after my tulips are spent. I always need a little extra soil to plant the petunias or pansies. There were a few other areas I used the potting soil to add a little extra soil. I had one pot on the deck where I planted a tomato plant. I had four citrus plants on the patio, but I only put potting soil in two of them as the other two were full up of soil.
The mustard test in all of the areas where I put the potting soil showed that there were worms everywhere I put the soil. I also tested many other areas of the yard and I did not have worms in areas that I did not use potting soil. In doing that mustard test all around the yard, I could mark all the areas infected and determine the spread.
Unfortunately, there was just me to do the work and the worms were spreading like crazy as the weather was still very warm. There is only one product that when watered in can bring the worms above the ground and kill them, a particular type of fertilizer called tea tree seed meal. I ordered $2500 worth of this fertilizer and by the time I got it the worms had spread far and wide across three acres. This cut down on the worm population a bit, but the worms are very good at hiding under every leaf or piece of bark or rock or brick that is in the ground.
When the weather in late December hit a high of 53°, the little worms started to hatch and there were millions of them under leaf debris and under moss. By this time, I had five acres of worms, millions and millions of them. My plan was to systematically clean off all the leaves, edging, bricks, etc. and water in the worm-killing fertilizer.
[While salt will kill worms, it also kills plant life. Tea seed meal is a non-toxic organic fertilizer that kills snails, worms, nematodes, aquatic insects, and other biota without polluting water and soil. It is used on golf courses, rice fields, in aquaculture and other industries as a safe alternative to pesticides and other harmful chemicals.]
There were so many worms at this point that the worms that came out of the ground and were laying there dying were so thick — literally a thousand worms in a 10 x 10 area — that you could not walk without stepping on one or two.
Identifying the Worms
Unfortunately, when the Department of Agriculture came out to check, they sent a person on a 16-degree day. The worms disappear underground at this temperature. A worm that they DNA tested at the Washington State extension was found to be of the species “lumbricus”. My understanding is that there are over 20 varieties of that species, one of which is the common helpful everyday earthworm that can live deep in the ground and bring up nutrients. They did not go into any further detail.
As I did not trust their analysis, and since they got their specimen when it was 16° out, I sent a video or two to University of Wisconsin where they are dealing with the Asian jumping worm. The expert there said he did not know what my type of worm was, but it wasn’t the Asian jumping worm. I understand that the Asian jumping worm drops its tail to get away from predators and can run faster than a human can catch it.
There was no help from the master gardeners because their director believed these worms were not a threat because they were not Asian in origin, but a type of European worm. There has not been any help by any government agency. In fact, they all claim that since these are not Asian worms, they are not a problem. But I have discovered they eat all the seeds and they eat the roots of the plants.
It is obvious that my worm is invasive and not common to other people in this area. It lives in the upper part of the soil, or just on or under deciduous leaves and bark and moss. They also live under roots of plants, and eat the root hairs, because I have a number of plants that were destroyed because they have no root hairs. I have about 20 established blueberry plants in one area of my garden and the year before last they had an amazing crop. This year, nothing. And you can grab the blueberry and pull it right up out of the ground because there are no small roots anchoring it now. I have had many plants that I have just burned because they were practically dead, and not from lack of water last summer as I was very proactive in watering my yard.
We have dug up and destroyed thousands of dollars worth of plants. We are in the process of pouring some concrete in an area around our house, because we no longer can have bark. We must take all the ground down to bare dirt to make it possible to destroy the worms. All plants that touch the ground will have to be destroyed.
Taking soil down to bare ground.
There is not a day that I do not go outside and do jobs to eradicate these worms. I have discovered that the fertilizer will eradicate all the worms in an area but that more eggs will hatch in about 4 to 5 weeks so every inch of the ground must be redone in that amount of time. Worms can reproduce very quickly, with a single worm producing 500 to thousands of hatchlings in a year. They can migrate surprising distances. We have discovered that the worms have already traveled a mile down the road.
I have run across some of the hatchlings under some of the plants like the hostas. There can be hundreds of little hatchings jumping around. We also have a tennis court that has been fairly clean through the winter except for a few deciduous leaves that had fallen on the court. If you turned over any leaf, you would find three or four worms on each leaf. They climb very quickly and somehow I managed to get a half a dozen worms in my house.
There is also the consideration that my 20 bags of potting soil were not the only ones contaminated with worms. A nursery owner I spoke with told me that she had a customer that bought potting soil in the area and that it was filled with worms.
I wished I would’ve had some help from the master gardeners or somebody, but I am only one senior citizen, and there is only so much I can do every day. I also am committed to homeschooling my grand children, which is a big priority. This is going to be a big problem for our community and I will be happy to help anyone to discover if they have a problem and to help them if they do.
————————————-
Bonnie’s garden before the worm infestation:
