For the jaded gardener, these plants bring new form and color to the flower bed. But exactly what are perennials? And how can you best use them in your own landscape?
May we present perennials? Like a big box of new crayons, these plants give the gardener more to play with--a greater palette. All those colors and untried textures! There is such variety that you can truly find a perennial for any reason and for any season.
Perennials can quickly elevate a garden from the limited realm of marigolds and petunias and Pfitzer junipers and bring sophisticated textures and subtle colors to your landscape. And because perennials tend to linger and smooth the transition from one season to the next, the change in the seasons will seem far less abrupt--less like the click of a light switch.
What is a perennial? It is a plant that is neither as fleeting as an annual nor as woody as a shrub. It is difficult to be much more precise, because perennials are a huge and varied group of plants. They are the middle ground in nature and in the garden, smoothing the hard breaks and edges. Unlike annuals, which flaunt mostly bright colors, perennials can be bright and bold, or soft and subtle. You can have a garden that is a delicate hue of pink and lavender, or you can cast together golden yellow and bright blue for an entirely different effect.
Many perennials are grown merely for their foliage color or texture. Their leaves are seldom an ordinary green, and many are reddish or gray. Similarly varied is their form or shape. There are billowy perennials, mounding perennials and spire-like perennials. Very ordinary plantings of flowers suddenly seem extraordinary when the tall spires typical of many perennials appear in their midst.
Perennials have an honorable history in England, and to a lesser extent on our East Coast, but in California they were swept away by the tidiness of low-maintenance landscaping. Now, they are making a come- back, perhaps because our gardens are beginning to weather and are ready for a bit more complexity. Whatever the reason, you will see more perennials than ever at nurseries this spring and summer as growers and gardeners discover the value of these plants.
Most literature on perennials is of little help to Southern California gardeners, since it is more applicable to areas with harsher climates. And perennials are neither as perfect nor as troublesome as some of the writing about them would seem to suggest. The very diversity that makes them so attractive guarantees that growing them will be an adventure, especially in our area, where they behave so differently and where we can grow varieties that would not survive in harsher climates. Be prepared for some surprises--and some disappointments. Every perennial has a distinct personality that can be uncovered only after trial and error.
Unlike shrubs, perennials never develop persistent woody branches. Typically, they grow as clumps of stems that spread ever wider with each passing year. These are the perennials of garden literature-- herbaceous perennials--cyclic plants that grow and flower in spring and summer, die to the ground in winter, and return the following spring from roots that function much like bulbs. In England and in the eastern United States, they are governed by the definite seasons and thus perform to a strict timetable. Expert English gardeners have learned to control that cycle with astounding precision, but such schemes are pointless in Southern California's casual climate. Here, perennials come and go as they please, often ignoring the seasons.
Also, these herbaceous perennials often behave very differently in this area. Veronicas are a fine example, blooming not once, but as many as three times a year. The traditional regimen for herbaceous perennials is to cut them to the ground after they have flowered. In colder climates, that customarily is done in late summer or early fall, and it prepares the plants for winter dormancy. In Southern California, if you cut back veronicas after they flower (and you should), six weeks later they'll flower again, and again. They simply don't see any reason to quit in our mild weather.
To confound matters, we also grow all sorts of perennials that are not strictly herbaceous. At the very least, a tidy clump of foliage will persist through our mild winter, but an occasional flower in winter is almost as likely. There are even a few perennials that are at their best when every other plant in the garden is not.
It should be clear that any general discussion of perennials is difficult. Nevertheless, on the following four pages you will find specific information on some of the most commonly available perennial plants.