White

• Many perennials produce white flowers, especially in spring. Candytuft (Iberis sempervirens) prefers well-drained, alkaline soil. This small perennial grows between 9 and 18 inches tall and produces an abundance of white flowers in spring. To keep it flowering, cut candytuft back every other year. Candytuft is hardy in USDA Plant Hardiness Zones 3 to 9. The white guara is hardy in Zones 5 to 9 and thrives in sites with fertile, well-drained soil. A heat- and drought-tolerant perennial, the white guara produces white blooms from summer through fall. This plant is native to the southeastern United States and grows up to 4 feet tall. Other white, sun-tolerant perennials include asters, baby's breath and Irish moss.
  
  

Yellow

• Yellow perennials add a cheerful touch of color to the landscape and often attract butterflies and bees. The fernleaf yarrow (Achillea filipendulina) blooms with showy, yellow clusters of flowers that can reach up to 5 inches in diameter. The golden blooms contrast with the yarrow's fine, gray-hued foliage. The fernleaf yarrow grows up to 4 feet tall and prefers well-drained soil. The yarrow is hardy in Zones 3 to 9. Lantana (Lantana camara), a drought-tolerant plant, is hardy warmer climates, such as Zones 8 to 10. Lantana blooms from summer through fall with rounded clusters of yellow, orange and pink flowers, sometimes producing all three colors in a single cluster. A South American native, lantana attracts butterflies. Other sun-loving yellow perennials include coreopsis, primrose and basket of gold.
  
  

Red-Orange

• Red to orange flowers are best for attracting beneficial pollinating species such as hummingbirds. Redhot poker (Kniphofia uvaria) thrives in full sun and well-drained soil. This dramatic plant produces tall spikes of bright red to orange blossoms in summer and grows up to 5 feet tall. Redhot poker is hardy in Zones 5 to 9. Beardtongue (Penstemon spp.) blooms with bright red to white flowers in late spring. It grows from 1½ to 3 feet tall. Plant beardtongue in Zones 5 to 8 in sites with well-drained soil. Other red to orange perennials for full sun include rosemallow, blanket flower and hyssop.
  
  

Blue-Purple

• Many perennials with blue to purple blossoms prefer shady sites, but some thrive in full sun. Cupid's dart (Catananche caerulea) blooms from June through August with blue to purple blossoms. A drought-tolerant perennial, cupid's dart prefers well-drained to dry soil. Cupid's dart grows up to 1.5 feet tall and is hardy in Zones 4 to 9. The early-blooming larkspur produces blue flowers in spring. Hardy in Zones 5 to 9, the larkspur is native to North America and reseeds itself easily. Plant in well-drained soil. Other blue to purple perennials for full sun include forget-me-not and pincushion flowers.