Hardy Full Sun Perennials

Yarrow

• Yarrow's (Achillea millefolium) ability to tolerate cold and drought cement its position on any hardy perennial roster. The plant can grow in U.S. Department of Agriculture Plant Hardiness Zone 3, where minimum winter readings can be as icy as `

  -40 degrees Fahrenheit. The plant can withstand dry periods and actually grows best in dry soils in a full sun situation. Yarrow grows as high as 3 feet and it possesses aromatic leaves and flowers that last from late spring into early autumn. Yarrow is originally from Europe and Asia, but its hardiness helped it to colonize most of the eastern half of North America. Use yarrow in cottage and wildflower gardens or cultivate it in meadows.

Siberian Squill

• The cold hardiness of Siberian squill (Scilla siberica) is beyond question, with this native of southern Russia growing northward to Zone 2, where it drops on occasion to -50 degrees Fahrenheit. Once the plant receives sufficient moisture during the initial phases of the growing season, it is hardy enough to go without water for long spans during the summer. Siberian squill grows from a bulb, attaining heights of 6 inches and producing striking blue flowers that resemble a drooping bell. Plant Siberian squill in your lawn in masses or utilize it in rock gardens. Bury the bulbs in the fall in average soil in full sun during autumn, placing each bulb from 2 to 3 inches under the surface for best results.

Heath Aster

• With an ability to grow as far north as USDA Zone 3 and south to Zone 9, the heath aster (Symphyotrichum ericoides) shows tolerance for both cold and heat. This hardy perennial is also capable of sprouting up in poor quality soils and thriving, even in sandy or clay soils, as long as they drain all right. Heath aster grows in full sun and like many types of asters, it blooms late in the growing season, from August until October. The plant grows to between one and 3 feet, making it usable in rock gardens, wildflower gardens and as a perennial border species. The flowers are only ½ inch across and feature yellow centers and white rays. Heath aster has few insect pests of serious consequence and the hardy perennial has excellent resistance to most plant diseases.