You are right in having soil tested before making decisions. Growing plants that consume large amounts of nutrients will do it in time ,mixing sawdust with soil will basically deplete soil of nutrients for a few months but will enrich soil after sawdust has rotted. Can you remove a root ball amount of soil and replace it with lean soil?

i understand a plant tolerating less than perfect soil... but im having a hard time about a plant failing for too good a soil ... sounds like some mumbo jumbo ...

there is a big difference between what a plant tolerates.. and what it requires.. and im wonder what plant REQUIRE bad soil ...

and to be clear.. no question is a bad question.. the search for knowledge is all we have...

drainage is a different animal.. if you rot the roots off anything.. it dies... period...

how do you think a soil test.. will tell if you soil is too good??? .... logically.. its tells you what you soil might be missing... but how would it report the converse???... perhaps your nitro is too high??... your pH out of wack??? .. i dont know.. im asking???

ken

ps: are milkweeds considered long lived plants.. mine lightly reseed themselves around.. but im thinking.. i never see many in the same spot after a year or 3 ...and i never grew yarrow.. so what up with that ...

Why do you think your soil is "too rich"? What did you add to it?

I have very lean soil but often divide my plants to use in customers much lusher gardens - the main result being plants get twice as tall and sometimes fall over. Do you think the issue might be drainage, Marie? Winter cold is never really a big problem but winter wet is a total killer (and did for shedloads of mine, this year).

Milkweed does fine in moist, rich soil for me. I've only grown yarrow in relatively dry soil, so not sure about that. Am also wondering if the issue is drainage.

My milkweed is in a bed with rich soil and gets 4-6 feet of snow piled on it every winter…never an issue. I doubt yarrow would like it there. Those are two plants with very different preferences for soil conditions.

tj

I'm not surprised that the idea of overly rich soil being undesirable sounds strange to some folks that frequent soil,compost and mulch. Being born on a farm and having gardened for more years than I like to recall,I've always looked for ways to organically enrich my soils until very recently. The wake up began when I saw what my dil did with tomato transplants I gave her. Her container grown plants far exceeded production of my in ground plants 4x as large from same batch of starts. My opinions were farther altered after looking into container gardening,something I had little interest in the past. Folks growing plants in pots that are known to be challenging rely on practices we organic fans discourage. Commercial fertilizer and conifer mulch to name a couple. How this relates to issue posted by OP is container gardeners "spoon feed" plants for lack of a better term. That is to say they give plants their daily ration no more,no less whereas we strive to build rich soil which supports plants long term between amending. They prefer conifer bark for the reason we avoid it,not quick to break down. Don't quote me on any of that,I'm in the infancy of learning, go over to forums with difficult to grow plants to draw your own conclusions. Many wild ancestors of plants we grow will hardly germinate in typical garden soil,much less thrive. All that to say I've learned after all this time that it's possible to "love your plants to death".

I'm very surprised that you lost Asclepias and Yarrow. I thought those two plants were indestructible. I've grown both in clay soil that is loamy, so probably not as lean as they like but they seem to perform the way I'd expect them to, so maybe my soils is average soil. It's definitely a bed that I have not amended and I don't apply fertilizer to those plants.

My garden is dry rather than wet and drainage is not an issue except for plants that really have to have it. I lose Agastache due to drainage and hardiness issues. Some Salvias too.

What species of Asclepias are you referring to? There are many, with widely varying soil preferences.

What kind of Asclepias? They like different conditions sometimes and it might matter.

i am beyond pissed. i lost a long and intelligent answer to your questions. The shortest answer is too rich soil is an assumption i cannot substantiate. A soil test will tell the % of organic matter in the soil. .

theres never standing water in the area in question

ive dug holes nearby when i planted clems, filled with water and watched it drain. It does within minutes. .

when i swueeze a ball if soil it sticks together but is not sopping. the soil is not clay.

How else can i check drainage?

the achillea were planted last summer 2022. several asclepius were 2 years, old old, a few were planted in 2022

more ideas? the asclepius were common orange ….latin nomenclature escapes me at the moment

"more ideas? the asclepius were common orange ….latin nomenclature escapes me at the moment"

That would be A. tuberosa (usually referred to by the common name, 'Butterfly Weed'), and it's definitely a species that won't tolerate wet winter soils (or thick mulch) at all. It has a strong preference for sharply draining, gritty/sandy soils, and I've even seen them growing happily in the wild in (nearly pure) sand dunes on the shores of lakes and rivers. In a garden condition, think of their soil preferences as being similar to that of Lavender, Agastache and Buddleia, if that helps.

Although they grow in the wild in poorer soils, rich/improved soils won't kill them, though they likely would end up being floppier and possibly with weaker flowering as well.

A popular native plant nursery near me recently told me they gave up on trying to overwinter their unsold (seed-grown) A. tuberosa container stock, as they just lost far too many of them due to imperfect drainage over the winter. They now only sell winter-sown seedlings that don't bulk up to "sellable" size until early-to-mid summer.

That information about not wintering over is interesting

I think my drainage is "imperfect"

Just chiming in to say that I have a self-seeded Asclepias tuberosa alongside Rudebeckia triloba growing intertwined in a crack between my sidewalk and the driveway--and thriving in a droughty situation in N. Central MD this year. I have not watered them but once. They must be growing in grit and whatever organic matter was able to insinuate itself into that tight crack over the years.