The anemone plant is one of spring's first and best bloomers. Several types of anemones are also repeat bloomers, beginning a second round of flowering in the fall which lasts until the first frost. Dozens of species of anemone grow around the world, occupying habitats ranging from open prairie to dry, shady woodlands, though many can be grown in the heavy clay soils prevalent in the southern United States.
About Anemone Plants
Plants of the genus Anemone comprise between 70 and 90 distinct species, with the majority growing in the Northern Hemisphere, especially in the United States and Canada. They are found growing north into Arctic regions but also occupy dry, semi-arid desert habitats as well. Plants are typically low growing, usually reaching between 4 to 10 inches in height, and put on displays of white, pink or purple flowers from early to mid-spring. Two groups of anemone are distinguished by their root structures: fibrous-rooted plants and bulb-root type plants. Bulb-rooted anemones typically flower only in spring, while fibrous-rooted anemones flower in the fall.
The Japanese anemone (Anemone x hybrida) is one type of anemone plant which is known to bloom both in the late spring and again in fall. Plants feature a low-growing basal rosette, or spiraled cluster of leaves at the ground, from which spring single or double-flowered blossoms. Flower color is generally restricted to shades of pink. Though somewhat slow to establish, Japanese anemone is quite tough once it becomes well rooted, surviving periods of moderate drought with little or no damage. In northern climates, a good mulching during the plant's winter dormancy will help it successfully survive the winter.
As a general rule, most types of anemone plant appreciates 4 to 6 hours of sunlight daily and placement in rich, well-drained soils. However, species such as the Grecian wallflower (Anemone blanda) are well-suited for dry, sandy soils and make excellent rock garden candidates. Most species of anemone will tolerate moderate, dappled shade and heavier clay soils, as long as plants are not over-watered.
About Clay Soils
A common misconception of clay soils is that plants fail to thrive in them because they lack adequate nutrients for plants to grow properly. The reality is that clay soils are among the most nutrient-rich soils; the reason plants usually have difficulty growing in clay soils is because of structure. Clay is composed mainly of very tiny, silt-like particles which cling closely together, limiting the amount of air which can be trapped between the particles. In well-drained soils, plant roots absorb a large quantity of their oxygen requirements from these air pockets, and since clay soils tend to become waterlogged, plants literally drown.
Amending Clay Soils
Gardeners can improve the workability of clay soils by amending them prior to planting. Especially in perennial gardens, where plants remain in place from year to year, it is important to be thorough, as amending soils after planting is extremely difficult without damaging or removing plants. In heavy clay soils, especially of the type prevalent throughout the southeastern United States, gardeners may consider beginning the amending process a year or two in advance of any actual planting. The heavy red clays of Kentucky, Tennessee, Georgia, Alabama and the Carolinas can be very sticky and difficult to work, and benefit from gradual amendment.
To improve aeration of clay soils, begin by mixing 2 inches of pine bark or other shredded wood humus into the top 6 to 8 inches of soil. Adding compost, decomposed leaf litter or even small-diameter pea gravel can greatly improve the drainage of most clays when dug into the ground to an adequate depth.