Answer: Some perennial flowering plants for shade and a moderately acid soil would include pulmonaria, lily of the valley, hostas (great foliage colors as well), lamium maculatum, tricyrtis, Solomon's seal, and many native wildflowers. Although not blooming plants, ferns are lovely in a shady garden and many prefer an acid soil.
You could also grow annuals such as impatiens and caladiums for additional color, although these would do better in a soil closer to neutral.
When you prepare a planting area you would want to work in a generous amount of organic matter such as compost or old rotted down leaves; this will usually help buffer the pH in addition to improving the soil structure.
Also, during the preparation stage, you could also add lime if necessary. This would be added in measured amounts (as would any other amendments such as fertilizer) based on the results of soil tests.
Your county extension should be able to help you with the tests and interpreting the results; they may also have additional suggestions about plants that would do well in your particular soil and location.
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