Pests on some Perennials

[Northerner]

Can anyone help me on this pest that is spreading in my perennial border? It started last year on my pink phlox, no sign of the critter but it ate most of the lower leaves. I thought I had it licked by spraying with sulphur and soap several times in the fall before putting the garden to bed, but now it's back and has invaded my lychnis, purple cone flowers, and the phlox again. The lychnis were moved there last fall and had bloomed beautifully last summer. I have sprayed with sulphur and soap a few times, but I fear the lychnis are done for. They are only about 3 or 4 inches tall, and all the lower leaves are brown and falling off. The cone flowers have holes in their leaves but they are surviving, and the plhox looks very healthy but is undergoing the damage on the lower leaves. I believe it is something coming from the earth, but see no sign of any invasive critter. Other plants around: lilies, peonies, hemerocalis, tulips, mallow,clematis are not affected. I have BTK and was considering using that in addition. I also wonder if laying a paper barrier around the stems between the earth and the leaves might help. Any ideas? I livein Ottawa, Zone 5B. Thank you.

[The Helpful Gardener]

Is it definitely chewing damage? Could splashed up fungii be defoliationg the lower part of these plants? Some fungus can look just like chewing damage.

Could also be slugs; try the oatmeal pellets listed elsewhere on this forum(when I remember where, I'll put a link up) Organic and enviromentally friendly; makes the slugs an even tastier meal for birds...

Scott

[Northerner]

Thank you for your reply Scott. I am sure slugs are not doing this - too dry and clear, no tell-tale slime. I even went out tonight to check and there were none there. The reason I think that something is eating is that the cone flowers are now about 10 inches tall, and all of the leaves have holes. This morning some of the upper leaves of the phlox had holes and that is a mound about 10 inches around. I noticed similar holes today on some of my sedums which are still quite small - about 2 inches high. I am prepared to lose some of these plants, but I had planned to amend the soil with some compost in the next week or so. Is there a chance that I could be 'feeding' this pest if I do so? Is there perhaps some treatment I should perform before placing any more plants in those parts of the border? It's still quite cool here. About 10 degrees Celcius at night.
Northerner.

[The Helpful Gardener]

No the compost is fine...

Are these holes, as in surrounded by leaf tissue and empty in the middle? Could be shotgun fungus, a type of leaf spot that actually leaves a hole and is often confused with insect damage...

[Northerner]

Your idea of shotgun fungus may be correct. This is a very old border with quite poor soil hence my intention to amend it. It's so cold here (7 degrees today) it's unlikely any critters are surviving and flourishing here. There is also a lot of splatter because these plants get the overflow from the eavestrough. Think I'll just go ahead and feed the soil with my compost and hope for the best. Thank you.
Northerner.

[The Helpful Gardener]

Try a tea of your compost sprayed on the foliage. This can be a very effective anti-fungal, at least preventitive and often curative...