Few things delight gardeners more than awaiting the yearly return of their perennials. Perennials are distinct from annuals in that they return year after year, eliminating the need to buy new flowers every spring.
- Unlike annuals, perennials generally bloom only one or, at the most, two seasons per year. There are spring bloomers, summer bloomers, or fall bloomers. When they're not in flower, perennials are enjoyed for their foliage, which is at least as important a consideration as the blooms.
- Perennial shapes and sizes also add to the mix. There are tall perennials like plume poppy that tower over your head and creeping perennials like moss phlox that carpet the ground.
- Perennials may grow and expand each year, eventually filling more space than you might expect. To keep perennials under control and growing well, many need division (digging up the root clump, dividing it into sections, and replanting the best sections in freshened soil). This can provide a harvest of new plants for use elsewhere in the garden.
Many perennials fall into the following shape categories. But you should expect variations as the seasons progress. Perennials usually stretch up to flower and then fade back to their foliage after the bloom is through.
- Mats: Perennials such as lamium, bugleweed, and plumbago form low carpets suitable for ground covers or the front of the border.
Mounds: Nicely rounded perennials such as coresopsis and hostas
provide a soft look.
- Flower sprays with low foliage: Perennials such as yarrow, sea thrift, and coral bells bear taller flowers over neat low foliage. Height is dramatically reduced when the old flower stems are removed.
- Vase shapes: When in bloom, plants such as garden phlox and Shasta daisies grow in an inverted triangular shape.
Spikes: Plants such as salvias, lupines, gayfeathe
rs, and delphiniums have slim, vertical flowering stems that contrast well with more horizontal forms.