yes, but it can be a big job, removing the some of the rich topsoil. An easier solution you could also consider is planting many sunflowers as they will leach many of the nutrients from the soil over a growing season (they are often used in phyto-remediation schemes to remove toxins such as heavy metals). Broadcast the seeds over the area - still time to do a sowing now (just) and make sure you remove all dying greenery when flowering is over.

i know you are looking for more heavy labor.. lol ...

but just get a yard or two of slag stone ... remove 8 inches of good soil ... insert slag ..

and grow your plants in rock .. cant get more inert than that.. lol ...

actually .. in the way back machine.. i dabbled in alpines ...and growing on the sides of mountains.. in the attendant slag heap ... with supreme drainage ... the only way to accomplish such.. was to get the yard of stone delivered.. and make my own little mountain ...

there is nothing i hate more.. in the garden.. than dealing with stone .... so i presume.. you will rule this out .. promptly ... lol

ken

First of, I would say make sure that you don't have floppy plants. Some achillea, I find, tend to be floppy no matter what. Second, how about amending the soil you want in pots and burying the pots and planting the plants in them? Much easier to control.

I'm with Karolina11 re achillea/yarrow & poppies. Grew/planted both and after seeing how they performed, no longer have either. There are just so many other things that behave the way I prefer, I just choose not to waste time on things that don't. My next-door neighbor has poor soil and her yarrow still flops over so I knew ahead of time I wouldn't likely have good results--my soil is amazing (thanks Mom & Dad for organic gardening the first 50 years you lived here).

nonetheless, if you want to grow a wildflower meadow for example, rich topsoil is actually a deterrent - so much so that we often plant parasitic plants such as yellow rattle (rhimnanthus) to weaken the vigorous grasses.

If it is just floppy plants you are worrying about - consider doing the 'Chelsea Chop' - a cut back of (some)perennials in late May by at least a third.

People here have good ideas I've never heard of. Sunflowers, who would have thought it? They wouldn't fit into spots I have in mind.
I know about the "chelsea chop" but never heard it called that. Been cutting and pinching back at least once early in the season phlox,monarda,asters,astermoeia (whatever it is called now), boltonia for years.
I'm sure the centhrantus can take it but I wouldn't dare try it on the poppies.
I don't have an interest in achillea anymore. But huge orange poppies with geranium magnificum and tall purple allium and a dash of yellow something are too gorgeous to give up. Honest, it gives me the biggest thrill of the gardening year. This year I propped the poppies up earlly with pea sticks and a harness and they look ok. The geranium magnificum is big and floppy too, but pea sticks work very well.
Can the geranium be cut back before blooming and still flower successfully? Of course if the bloom is delayed too much it won't flower with the poppy.
I find the idea of sinking a pot with the correct medium interesting. Can't hurt to try.
Thanks everyone,
idabean/Marie

Raised beds!