Depending on general soil conditions, there can be a fine line between slightly acidic and alkaline—and “expert” sources provide differing information and many do not even address the matter. Here’s Cornell University’s page ( a generally reliable source) on hybrid astilbe > http://www.gardening.cornell.edu/homegardening/scene4f95.html and here’s their page on the Chinese astilbe > http://www.gardening.cornell.edu/homegardening/scenecea9.html . Here’s yet another (different source): http://hvp.osu.edu/pocketgardener/source/description/astilbe.html
A pH chart from Sonoma.edu cites “many species” of Astilbe and gives them a 6.0 to 8.0 pH range. Six is on the edge of acidic and 8 and running sweet, or alkaline.: https://www.sonoma.edu/users/s/shawth/pH%20Preferences
Here is one more, from the University of Minnesota coop extension that puts astilbe on its “Alkaline Soil” page, with a note (on the right) that “This list includes some of the best plants for soils with a pH of 7.0 to 8.0.” …some of the best plants…
We are not singling out these sites out for criticism, only citing them to explain the challenge, with this plant in particular. Thanks for asking.
Depending on general soil conditions, there can be a fine line between slightly acidic and alkaline—and “expert” sources provide differing information and many do not even address the matter. Here’s Cornell University’s page ( a generally reliable source) on hybrid astilbe > http://www.gardening.cornell.edu/homegardening/scene4f95.html and here’s their page on the Chinese astilbe > http://www.gardening.cornell.edu/homegardening/scenecea9.html . Here’s yet another (different source): http://hvp.osu.edu/pocketgardener/source/description/astilbe.html
A pH chart from Sonoma.edu cites “many species” of Astilbe and gives them a 6.0 to 8.0 pH range. Six is on the edge of acidic and 8 and running sweet, or alkaline.: https://www.sonoma.edu/users/s/shawth/pH%20Preferences
Here is one more, from the University of Minnesota coop extension that puts astilbe on its “Alkaline Soil” page, with a note (on the right) that “This list includes some of the best plants for soils with a pH of 7.0 to 8.0.” …some of the best plants…
We are not singling out these sites out for criticism, only citing them to explain the challenge, with this plant in particular. Thanks for asking.