|I need some type of shrub or flowering plant that can tolerate heavy, moist (i.e. not well drainable) clay soil that will provide, in order of aesthetic priority requirements, red, yellow, or blue coloration.
|Well, there are a few plants that will grow in clay....nothing really thrives there, you are much better off to try and amend the clay by working in organic matter (compost, composted cow manure, leaf mould, mushroom compost, etc.). However, here are some "clay toleraters" you can try. I might add, the list of plants that will grow in clay is so small I couldn't really stick to your aesthetic priority requirements. I'm going to give you partial shade and shade plants, all are perennial. Here is the list, partial shade to sun first: Lady's Mantle (Alchemilla mollis), Goat's Beard (Aruncus dioicus), False Spirea (Astilbe arendsii), Daylily (Hemerocallis), Self-Heal (Prunella webbiana), Buttercup (Ranunculus aconitifolius 'Pleniflorus'), and Lamb's Ears (Stachys byzantia). Now for partial shade to shade: Pigsqueak (Bergenia cordifolia), Hosta, Bistort (Persicaria bistorta). If you want to grow shade shrubs like azalea and rhododendron, you will need to improve the soil first with organic matter. They won't tolerate wet and heavy soil.|