Maybe a previous owner dumped something in that spot, so the soil could out of whack in that spot.

I'd investigate drainage issues.

I'm sure it's not a drainage problem. The soil is well amended and it's surrounded by daylilies, echnicea, and stokesia, all of which are doing fine. And those things are not intruding on the clematis' spot!

A previous toxic spill is interesting. But, because I've been mystified, each time I've planted a new clematis in that spot, I've dug a 2 x 2 x 2 hole. Wouldn't anything toxic be gone by now?

Are you starting off with vigorous healthy specimens?

Earlier in my years with Clematis I "rescued" a lot a half dead specimens for cheap or free and unlike almost every other plant I've "rescued" these Clems have never equalled the vigor of pots I've paid full price for that were in great shape.

I routinely buy half dead plants for cheap but I no longer do it with Clematis. I've been nursing some of these poor doers along for almost a decade!

Is the trellis or arbor put in the ground with cement to hold it? I found a pattern to my dead/living clematis problem............The ones planted next to new cement failed.

Cement leches lime and other chemicals into the surrounding soil. You can see this with grass that does not grow for years near new sidewalks. Bulbs are highly affected by the chemicals leeching from cement.

Could this be it?

It is also likely that a previous owner used salt to kill a noxious weed that was resistant to Round-Up and the like. Salt will never go away,

dillay dally, I'm not at all sure that there is a direct relationship between your "cause and effect" - concrete should have little to no bearing on whether or not clematis will thrive. Concrete does leach lime but it does so slowly over time and not in huge quantities, so that existing soil pH is only moderately affected. Certainly not enough to dissuade grass or most bulbs (?!) from growing, as these tend towards more alkaline soil conditions anyway. Its effects are most noticeable with acid loving plants like rhodies and azaleas and since clematis are known to tolerate rather alkaline conditions, I doubt this would be an issue in this case as well.

And most toxins would have been depleted by now, especially if you removed soil during your previous excavations :-) Salt will indeed "go away".......the actions of the soil and moisture break it down into harmless chemical components just the same as most other herbicides. Water is particularly beneficial in neutralizing the effect of common salts. The possible toxins I would be concerned about would be petrochemical in nature - spilled or dumped diesel or fuel oil, gasoline, oil based paints, etc. These do take rather specialized actions to remediate or the contaminated soil needs to be removed completely.

Based on the information provided, I do suspect something else is at issue and it might be as simple as BorS's surmise on the overall vigor of the plants. Or possible root damage from unknown, warm blooded sources :-)

Gardengal suggested:"Or possible root damage from unknown, warm blooded sources :-)"

That's where my mind was headed. I lost a quite vigorous Venosa Violacea to voles last winter, along with several other plants that were either killed or severely damaged. The little critters burrow in under the snow and then feast their little hearts out on the roots, crowns and tender shoots of my plants. At this time of year I find their tunnels by feel - the soil is soft and caves in when pushed on. I firmly pack soil into the shallow tunnels by pushing from above to discourage them.

Hi,

Sorry to have been absent; I was out of town for awhile. I only buy clems from Joy Creek and Brushwood. Learned my lesson a long time ago. So that's not it.

The clematis is in front of the deep front (cement) porch of this 100-year-old Craftsman bungalow. So that cement has been there a long time! Perennials front the entire porch, and about 12 feet from the spot where they've all been dying, a Roko Kollo lives happily.

Animal damage is of course possible, but I have twenty or so clems for them to choose from. Isn't it odd they always go to the same spot?

Pat