Perennial plants are loved by gardeners because of their remarkable ability to live through most winter conditions. Therefore they do not have to be planted every year. Perennials only flower for a few weeks each year, however, with careful planning you can have some perennials in bloom most of the season.
Perennials are perfect for the year round gardener. When planting perennials though you should give some consideration for how a plant looks when it is not in bloom. Perennials with colorful or interesting foliage can provide interest even when they are not in bloom. Annuals can be combined with perennials to produce a continuous colorful show.
But what is it about perennials that enable them to survive winter?
Other plants shrivel up and die as soon as the going gets tough.
The longevity of the perennial plant is definitely an exciting curiosity for many people.
Interestingly, perennial plants are able to survive year after year because of a few survival tricks they have. Many herbaceous perennials lie dormant over winter with their buds at or just below soil level. They survive the winter as a rootstock bearing a stem with leaf buds, or as underground stems and roots.
The perennial plant gears up for the winter by draining its own food supply from its leaves down inside its stem, branches, and root. As the weather gets cold the tissues of a perennial plant will slowly change and become cold resistant in a process called “hardening.” During these changes, the chlorophyll of a perennial plant will decompose and lose its propensity to project a green hue. We also see this in trees as they develop their trademark red, yellow, orange, and brown autumn leaves.
Here are some examples of perennials and how they survive the winter as dormant storage organs that grow as modified roots, stems or leaves. The roots of Paeonia for example swell up to form root tubers from which the plant normally produces strong re-growth in spring. Lupins have deep growing tap roots. Anemone survives as a rhizome, an underground stem and storage organ. Rhizome growth is horizontal, their buds sprout in spring. Gladiola and Cyclamen survive as corms – wide vertically growing underground stems and storage organs.
Another one of these survival tricks is that even though winter is definitely cold, the air temperature is far colder than in the ground beneath. The soil is an excellent retainer of heat, and as long as it has adequate insulation between it and the air, it will retain some of this heat thru the winter. It may surprise you, but with enough insulation from fallen leaves and deep snow, the ground may never actually freeze at all during the winter. This may be true despite the fact that you may have days of 30 degrees below temperatures. You can see where this is going. So one of the keys here is clearly the insulation, which is anything that stands between the warm ground and the cold air above.
Perennials also protect their next year’s growth with waxy scales. Examine the bud of a perennial plant and you’ll see that it’s covered with a sticky looking waterproof wax. When the bud begins to bloom, it scars as its scales fall off and the new growth begins.
Many herbaceous perennials grow and flower for several years. There are some perennials though that survive for only three or four years.
Every gardener looks forward to the spring when their perennial friends come to life again. The plants start to grow new leaves from their crown or root and a new season of life and growth and beauty has begun.