CONTROLLING LAWN CULTURE WILL FEND OFF EARTHWORMS
There’s a chemical solution, but it also kills the beneficial flora and fauna
Q Over the last few years our lawn has been invaded by large earthworms. They leave mounds so big that when you walk on the grass it feels like you’re walking on a gravel road. The problem is so bad I had to buy a self-propelled push mower because I could hardly mow the lawn with my old standard mower. Is there anything that can be done to get rid of them or slow them down?
A We have addressed this issue of dew worms in the past but it has been a while, so let’s look at it again.
Cultural control is vital to winning the battle with these creatures, because they like old established lawns that have a lot of thatch buildup.
Chemicals may kill off some of the worms but the problem with this method is that you may drive them into your neighbour’s lawn, and then after a time they will come right back.
A healthy lawn will go a long way to controlling the worms, but the key is keeping the invaders below ground.
You should be aerating the lawn twice a year, in the spring and the fall.
Dethatch your lawn professionally each year.
You want to remove as much of the thatch as possible.
Maintaining the right moisture levels will help as well.
Water deeply when watering and less frequently, as opposed to watering shallowly and more often.
The less water the better. An inch of water applied every week works best.
You can try an application of sharp sand as a top dressing, as the dew worms do not like crawling on the rough surface.
If you are going to go the chemical route, there is a chemical registered for use against this pest called carbaryl.
The last product on the market that has not been banned that contains carbaryl as the active ingredient is Sevin, a chemical that is not safe for animals or children or pregnant women.
The problem with using this chemical is that you will not only kill some (not all) of the worms, but will also kill all of the beneficial flora and fauna that lives in the lawn.
Personally, I think that attacking the issue from a cultural standpoint will be successful in the long run.
Patience is the key here. This is a difficult problem and I understand that.
I wish I had an easier solution.
Many years ago I was the keynote speaker at a gardening symposium and my topic was on companion planting. The definition of companion planting is “the close planting of different plants that enhance each other’s growth or protect each other from pests.”
Companion planting is part folklore and part science, but there are definitely plants that can keep some pests at bay (or at least reduce the attractiveness of some plants to certain insects).
Marigolds and chives are two possibilities.
I recently received an email that triggered a memory and the idea to share with you the possibility of using these plants as repellents for insects.
Here is the email I received: “Your articles have given me many gardening hints over the last 35 years when I started gardening in Alberta. Gardening here is a much bigger challenge than gardening in Ontario.
People often ask you about aphids and how to control them. I discovered long ago that chives are an excellent aphid repellent. I have chives all over my yard and very seldom see an aphid.”
I have used chives as repellents myself.
I have also used marigolds to keep insects off of my tomatoes.
There is anecdotal evidence of certain plants enhancing the growth of other plants as well.
I recall visiting an elderly Italian gardener in the city and being very interested in the fact that he grew the largest tomatoes I had ever seen.
When I asked his secret he said that he plants rows of basil between the rows of his tomatoes.
Is it a scientific fact that basil helps tomatoes grow?
Probably not, but they were the biggest tomatoes I have ever seen.
If you are interested in learning more about companion planting there are many books out there on the subject but one of my favourites is Carrots Love Tomatoes by Louise Riotte.
Good luck and happy gardening! Gerald Filipski is a member of the Garden Writers Association of America. He is the author of Just Ask Jerry. Email your questions to filipskigerald@gmail.com. To read previous columns, go to edmontonjournal.com/filipski