Documents: Special Interest:

Petunias, MYKE & Norway Mape

Questions about cutting back petunias (yes, it’s not too late!); MYKE; and heeding arborists’ advice about an old Norway maple.
by Art Drysdale
by Art Drysdale


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

July 25, 2004

Our two ponds are little closer to completion this week. On Monday, the concrete contractor arrived and the bases for the ponds were poured. In the photos above are the small pond almost completely poured and the larger one ready for pouring with the wire mesh over an area where we had to take out a large old tree root. In the photos below are various stages of pouring the large pond, and the final finishing of the small pond.
Author photos.

Still more questions this week. The first came from Sandy Reid in Ontario: “My mother is visually impaired and listens to 740 AM. Yesterday morning you talked about cutting back Petunias to encourage new blooms and my mother missed the instructions. Could you please direct me to a web site where I can pass on these instructions or if you could answer this e-mail with the instructions, it would be most appreciated. After she missed your comments on the radio, she called the garden centre who said it was too late to cut back Petunias.”

It is not unusual for garden centre employees to get things wrong, that is why I always suggest that if you are seeking information at a garden centre that you seek out either the manager, or a qualified horticulturist. That is not a guarantee that you’ll get the right info, but at least you’ll have a better chance. The following is the full vignette that Sandy referred to.

Generally about now, petunias begin looking rather forlorn--still plenty of flowers, but all emerging from the ends of long sticky branches of not great looking foliage. This is not an unusual problem, and there is a very quick fix. But, you must be ruthless! Take a pair of sharp pruning shears or secateurs and cut back all of the branches to about one-third of their present length, or even less. In other words, give all of your petunia plants a brush cut! Now I know this will remove all of the flowers, so you'll have just foliage for about a week or so. But the action of cutting back the plants will encourage them to bush out again in a much more compact form, with many, many more flowers. There is another part of this operation that is likewise important. That is fertilization. Regardless of whether or not you have fertilized your petunia plants recently, when you cut them back, give them a good feeding with a soluble plant food--applied both to the foliage, and generously to the soil. The action of cutting the plants back, together with additional instantly-available nutrition, and the established root systems of the mature plants, will mean you'll have substantial new growth, and many new flower buds likely within ten days, depending on the weather conditions. Now remember, you have to be ruthless with this operation, cut back all the leggy petunia plants to one-third or less of their present size, and then fertilize well. This technique applies to other annuals such as Bidens and Alyssum too.

Irene Smith, also from within the prime listening area of Toronto’s AM740, wrote with the following request: “My husband and I listen to your radio station and love the music you play, Sundays I enjoy the Scottish music since I hail from Hamilton, Scotland. A week or so ago I was listening in the car when I heard Art Drysdale speak of a product which puts back into the soil essential nutrients depleted over the years. Would you be able to tell me what this product is and where it can be bought? Once again we love your radio station and we will keep listening, great job.”

As it happens, that is the second such question in just a week. The product I referred to is MYKE, which are natural mycorrhizal fungi from the Premier Tech company in Québec. Here is basically what I have said.

The concept of adding mycorrhizal fungi to the soil is far superior to adding excess fertilizers continually. Mycorrhizal fungi have been in our soils for about 400 million years. The trouble is most of our gardening soils have been ‘attacked’ by construction work and/or intensive cultivation with high levels of fertilization and these have caused the natural supply of mycorrhizal fungi to decrease beyond the point where they are beneficial. The answer then, is to add these useful fungi to soils so they can grow in association with the plant roots. Once they have grown in the soil, mycorrhizal fungi create their own networks in the soil that increase the absorption capacity for water and the nutrients it bears. This, obviously then, leads to better plant development and growth. For the past 17 years Premier Technologies in Québec has been developing (growing) disease-free mycorrhizal fungi, and has introduced a line of products under the trade name of ‘Myke’. This year there are specialized products for vegetables, annuals/perennials, trees/shrubs/hedges, lawns and bulbs. These new products are available at selected good garden centers across the country. In their research Premier Tech has developed a method for laboratory growing of the fungi that absolutely guarantees disease free results. Gardeners I’ve spo-ken to, who have used the product, like it and plan to use it with all future plantings. Just remember that it’s important to get it down where the plants’ roots are. The product is Premier Technologies MYKE—M-Y-K-E.

In addition to that information, the MYKE product line now also includes organic fertilizers. You may look up the company’s Website at

Finally Jen Leitch wrote a lengthy question about an old Norway maple tree on their property. Here’s what she said. “A Norway Maple in our front yard is approximately 30-35 years old. It is a very large tree providing excellent shade, but recently we have been having problems with it. Last year it had tar spot and what seemed to be too much deadwood. We obtained prices from two different arborists, one of whom said our tree had a bleeding canker. It was suggested that we prune and fertilize the tree, which we planned to do this year. Now though, the tree looks even more sickly with more deadwood, several branches with droopy, dying leaves, and a large crack in the trunk which we assume to be the canker as it does bleed a lot of sap. We called an arborist who is a friend of our neighbour and it turned out he is one of the ones who looked at the tree last year. He has also seen the tree this year and advised us not to waste our money--the tree will be dead in three years at the most.

“We cannot give up on our (once) beautiful tree that easily. We have discussed doing some pruning and fertilizing ourselves, but would like to know if there are any treatments for bleeding canker? If the arborist is right and the tree is dying anyway, why not try to treat the tree in any way possible? Are there any radical, aggressive new theories out there? Any rogue tree doctors who aren't willing to say never? We'd do just about anything to save our tree--it's irreplaceable.”

First let me comment, for the benefit of other gardeners whose maple trees exhibit tar spot (the large black blotches on the leaves in autumn), that they are separate from any other problem, and very likely not at all connected. Second, although I would suggest you get still another opinion, say from my good friend Ian Bruce of the Bruce Tree Expert Company (416-252-8769), the advice you have received is likely right on. I think your first priority, probably this fall, should be planting a new replacement tree, so it can have a few years in which to get established before the Norway succumbs or has to be cut down.

I would suggest fertilizing with a soluble or liquid plant food on the foliage with some sort of wand pressure sprayer. I would do that weekly until toward the end of August. Flooding the grass or soil that surrounds it will not go astray either. I do not believe there is anything new for the canker, but you can ask Ian Bruce that question. You may well be able to get the tree to hold out for three or more years until your new tree achieves some reasonable growth.

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