To be perennial means to endure. Unlike annual plants, which complete their lifecycle in a single year, perennial plants continue, year after year.
The most obvious perennial plants are trees, some of which lives for hundreds, or even thousands, of years. You won’t get that kind of longevity from shrubs, bulbs, or other perennial plants, but you will get the other benefits of growing perennial plants.
Advantages of perennial plants
The single biggest benefit of perennial plants is that they do not have to be planted each year. Perennials are able to develop more extensive root systems, making them less susceptible to drought and able to reach more nutrient resources. This makes them more resilient to water stress and more resistant to pests and disease than more tender annuals.
Flowers add more than color to a landscape. Nectar and pollen attract beneficial insects that attack pests and increase yields through improved pollination. Perennial flowers, such as lavender, hydrangea, daisies, echinacea, hollyhocks, phlox, crocus, and tulip can either add year round structure or seasonal splashes of color to the garden.
Most herbs are tenacious perennials. Planting rosemary, thyme, bay laurel, chives, fennel, lemon balm, oregano, lemongrass, marjoram, mint, ginger, parsley, sage, and tarragon can provide many years of culinary delight with very little effort on your part. The only exception is parsley, which is technically a biennial. Biennials take two years to complete their lifecycle, although I have had parsley plants last 3 - 4 years.
Perennial shrubs & trees
By definition, all shrubs and trees are perennial, but a few varieties provide the added benefit of being edible. Edible shrubs include blueberries, currants, gooseberry, hazelnut, pineapple guava, and dwarf pomegranate. Trees can provide a wealth of fruits and nuts in practically any landscape.
Perennial vines & cane fruits
While grape vines are most productive during their first 20 years of life, they can continue for over 120 years, making them one of the longer lived perennials. While they may not look neat and tidy in a landscape without a fair bit of effort on your part, blackberries, raspberries, dewberries, loganberries, and boysenberries also deserve consideration for the delicious fruit they provide year after year.
Aside from herbs, trees, and shrubs, there is another perennial that deserves mention: stonecrops. Stonecrops are a family of succulents that come in a wide range of amazing shapes and colors. Succulents can survive even the worst neglect and still plump right back up after a light rain or watering.
Of course, the same strengths that make perennial flowers, trees, and shrubs so durable also makes some weeds harder to get rid of in the garden. Annual dandelions may require some effort to dig out, but perennial bindweed roots can go 14 feet deep or more!
Adding perennials to a landscape creates a stronger sense of continuity between the seasons and the passing years. Unlike the fleeting acquaintances of annuals, perennials establish themselves as durable members of the landscape.
I hope this information inspires you to grow more of your own food. You can ask your garden questions on my Home page.