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Fairy Ring and Rabbit Damage

Questions about mysterious darker green circles in grass; leaves falling from an azalea, Doktor Doom for mosquitoes; pruning an old lilac and rabbit damage to Euonymus shrubs
by Art Drysdale
by Art Drysdale

email: art@artdrysdale.com

Art Drysdale, a life-long resident of Toronto and a horticulturist well known all across Canada, is now a resident of Parksville, British Columbia on Vancouver Island, just north of Nanaimo. He has reno-vated an old home and has a new garden there. His radio gardening vignettes are heard in south-western Ontario over radio station Easy 101 FM out of Tillsonburg at 2 PM weekdays.

Art also has his own website at http://www.artdrysdale.com


April 13, 2003

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Above, no, they aren’t crop circles but they are mysterious. I believe these are the trade-mark circles of a disease known as Fair Ring; below, the 450 mL can of Rabbit Repell, a Nu-Gro/Wilson product generally available at garden centres.
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Though the weather would not seem to indicate so, we are about to enter the peak outdoor gardening season! That usually results in a much higher number of questions, and this year is certainly not the exception to that. From Bolton Ontario, listener Gord Kenmir e-mailed: “Hi Art, Listen to you on AM740 and wonder if you may have a suggestion to clear up what to me is a bit of a mystery. We live in a new subdivision and our lawn is now going into its third summer. Circles appeared last year and a local shop suggested a spray for Cinch bugs. Now I don't know if this really is Cinch bugs or maybe I just didn't apply the spray at an optimum time. It's now Mar. 29 and the frost just came out of the soil. Does this look like Cinch to you? Do you have any suggestion on what we might apply, and just when is the best time? Or perhaps this problem requires two or three different treatments? I do plan on doing some re-seeding, Appreciate your comments!”

From the photo that Gord sent (which appears to have been taken early this spring) I cannot say for sure just what the problem is, although it might be a disease problem known as Fairy Ring. The one thing of which I am certain, Gord’s problem is NOT Cinch bugs!

Fairy Ring is one of those odd diseases that infest lawns of different types all around the world. I personally had a fairly bad case of it just before I eliminated my front lawn (in favour of a landscape planting) at my Hopedale Avenue home in Toronto, back about 1983. Various fungi cause Fairy Ring disease, and because of this, there are generally small fruiting bodies we know as mushrooms that appear along the inner margin of the outer green band in late summer. While there are other fungi that cause this, in eastern Canada it is usually Marasmius oreades that is the offending one.

While a fair bit is known about this fungus, no easy solution has been found to “cure” the disease. One old recommendation is to establish and maintain a heavily water-soaked condition in the total area of the problem. This needs to be maintained for a month or more. Start off by flooding the area by using a tool such as a Ross Root Feeder to get the soil beneath the affected area totally soaked. Then maintain this condition by heavy watering (at least 3 cm of water) every second day. If the soil is sandy more water will be needed, if it is clay, probably slightly less.

The presence of the water usually brings the Fairy Ring fungus under control due to increased soil bacterial activity and the increased presence of other antagonistic fungi. The addition of the MYKE Lawn Fertilizer 10-3-3 now may well aid in overcoming the problem.

With regard to Gord’s comments about re-seeding and fertilizing this spring (he named a specific chemical fertilizer) I suggest he change to an organic approach, using either the MYKE fertilizers (the spring formulation mentioned plus the MYKE 9-4-2 for the summer and MYKE 3-3-8 for the fall) or the Gaia Green Turf & Lawn Blend 6-2-3. In the case of the latter, an application of Gaia Green’s Glacial Rock Dust prior to any heavy watering treatment might well speed up the demise of the offending fungus.

The next question was a simpler one, from Wilma Schuring, who, judging from her e-mail address, hails from somewhere in Alberta or British Columbia. She says, “Can you tell me why my azalea drops all of its leaves?”

It doesn’t really matter where Wilma lives in Canada, although I do always ask that you tell me your hometown when writing with a question. Azaleas are generally easy to over-winter, but they do need some humidity and reasonable light. If that was provided, you should have flowers on your over-wintered azaleas as we do now. If all the leaves are dropping, and that’s been happening most of the winter, the problem likely is not enough humidity. Remember, that’s moisture in the air, and has nothing to do with watering the plant’s growing medium.

When you do water the plant, once it has some leaves, the addition of some fertilizer won’t go astray either.

‘Sittyslicker’ writes, again from an unknown location: “I am hoping you will tell me about Doktor Doom, specifically for mosquitoes. We are interested in knowing if this product is natural or is chemical based. How is it used? We are looking for something to use at our cottage to repel mosquitoes from the area. Would this be something we might try? I thank you kindly for any further information you might give me about this product or any other that may be of use. We would like to sit outside at the cottage and enjoy our gardens without total worry about West Nile virus. Thanks so much!”

Well, providing ‘Sittyslicker’ can tune in to my AM740 programme this Saturday, he or she will likely hear Doktor Doom himself (a.k.a. Grigg Kellock) talking on this topic.

The product of choice is the Doktor Doom Residual Spray, which contains 50 percent Permethrin. This product is residual for up to two months, but sprayed onto a lawn for mosquito control will likely only last a couple of weeks, depending on the amount of sunshine the lawn receives. Sprayed onto surfaces not exposed to sun, the product will last a full two months. If you spray the lawn around where you sit, mosquitoes will not bother you. for a couple of weeks. The product is a man-made form of Pyrethrum, one of the oldest ‘natural’ organic insecticides. The product does not need nor carry the famous “Poison” label. While it’s not recommended that pets or people walk on the lawn while it is wet with the spray, there is no danger once the lawn has dried. Also, it’s best to cut the lawn before spraying it, and then when next you cut the lawn, to leave the clippings on as it is those tips of the grass blades that will still have the residual spray.

Linda Todd, again from a location unknown, asked: “I have a common lilac which is 15 years old. I have kept it pruned from the top as it borders our deck and cleaned out around the bottom. The problem now is the foliage/bloom area is getting narrower. If I bite the bullet and just cut it right back after it blooms this spring, will it survive and how much length should I leave on the trunks. Keep in mind that these trunks have virtually no foliage on them, just a few little sprouts. Also, is this a good time of the year to do some minor pruning on a dogwood. It would be so easy as I can see the shape I want to take before it leafs out. One last thing. There is an old currant hedge on our property line. It has gotten very leggy and out of shape. I was advised in the fall to cut out the thick stems and let the new shoots come on. This didn't get done. Can I do it now before it leafs out? Thank you for any help you can give.”

Pruning old lilacs is relatively easy, and the bullet is not so hard to bite. First, prune out all of the old, thickest branches much as you were advised for the currant hedge. Then on the thinner branches, you may cut back those growths as much as one half, but try to do it judiciously so that each one is cut at a slightly different level, so the shrub won’t look as if it was given a buzz cut! And, remember don’t do this until immediately after it finishes flowering.

When Linda mentioned a dogwood, I assume it is not one of the flowering dogwoods, but rather a red- or yellow-stemmed, or alternifolia type. If so, that could easily be done now, again keeping in mind to do it judiciously so that the end result is a pleasing informal shape. And yes, the currant hedge would be best pruned now even before the leaves emerge.

Finally, Honor A. Welch, sent the following: “How do I keep rabbits off my garden? Its looks like I have lost a lot of Euonymus plants this winter; they are stripped bare. Should I remove them or will they grow again? We spoke at a garden centre one or more years ago and you where going to move to Victoria, B.C. Good luck and thanks.”

Well, I did move to Vancouver Island, if not specifically to (busy) Victoria! And here too I have rabbit damage; currently they’re eating the tops off many of my tulips so I have just sprayed some Thiram. The form I used was Wilson Rabbit Repell that can be painted or dilute in half with water and applied with a pressure sprayer.

The Euonymus plants will likely come back, at least from the roots if the branches themselves do not send out new growths.


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