Early Season Bloomers

• Foxgloves are one of the first on the scene come springtime.Hemera Technologies/Photos.com/Getty Images
  
  Start the spring season with yellow daisylike doronicums, whose blooms last for four to five weeks. They grow best in full sun in temperate climates or partial shade in hotter regions.
  
  Foxgloves make their appearance in the late spring to midsummer, with flower colors ranging from cream, pink, purple, red, white and yellow. Plant foxgloves in full to partial shade.
  
  Reminiscent of forget-me-nots, bugloss have brilliant blue flowers that open in succession up the stalk starting from mid-spring and lasting throughout the summer. Bugloss adapts to nearly any soil and prefers full or partial sun.
  
  

Late Season Bloomers

• The versatile aster thrives in clay soil's tough conditions while providing abundant fall color.BananaStock/BananaStock/Getty Images
  
  Asters vary greatly in size, shape and color but have a general appearance that resembles daisies. They produce blue, lavender, pink, white, purple or red flowers that provide color to the fall garden, and they prefer full sun.
  
  Aconites resemble delphiniums in physical features but are more pest- and disease-resistant. They bloom from midsummer to late fall and prefer full or partial sun.
  
  Fall-blooming sedums can withstand moist conditions in partial shade. Sedum flowers last for six weeks or more and come in pink, purple, red, white or yellow.
  
  

Attracts Wildlife

• Attract wildlife to your clay-loving perennial garden by planting purple coneflower.Andy Sotiriou/Photodisc/Getty Images
  
  Butterflies love yarrow's sprawling clusters of red, pink, salmon, lavender, white and yellow flowers that last for three months during late spring and early fall. Plant yarrow in full sun, and deadhead to avoid weediness.
  
  Rudbeckias attract butterflies and birds with their cheerful yellow petals and brown nectar-rich and seed-bursting centers. They grow well with purple coneflower, another clay-loving perennial that attracts wildlife. Plant both species in full to partial sun, and watch them bloom throughout the summer and fall seasons.
  
  Yellow, daisylike coreopsis is a tough yet delicate-looking flower that needs little maintenance and is a favorite of butterflies.
  
  

Showy Blooms

• Add color and flare to your clay soil by planting daylilies.Medioimages/Photodisc/Photodisc/Getty Images
  
  Irises produce showy, exotic-looking flowers in a range of colors, such as blue, yellow, purple, pink, white, orange and red, that last for about two weeks. Viburnum is a popular and easy-to-grow shrub with large ball-like clusters of white and shades of pink flowers. The foliage turns orange or reddish-purple in the fall.
  
  Goldenrods burst into fireworklike yellow lance-shaped flowers that last five weeks or more when planted in full or partial sun. Daylilies have trumpet-shaped flowers that come in lavender, red, pink, yellow, white, purple, salmon and orange. They tolerate a variety of soils and light preferences and can thrive in drought or moist conditions.