Lifespan of perennial plants

What is a perennial plant?

Let’s take stock of what a perennial plant is:

• A perennial plant is a long-lived plant, meaning it lives for several years. It stores reserves in its root system (roots, bulb, corm, or rootstock) well protected from the winter cold. In winter, the aerial part disappears for deciduous perennials, while it remains for evergreen perennials. The following spring, growth restarts and new shoots appear from the stump. The perennial plant grows, flowers, and produces seeds (except for sterile plants) each year.
• It does not form wood. This distinguishes it from woody plants (bushes).

• Perennial does not mean vigorous! Perennial plants thicken more or less quickly and they actually start to look beautiful and floriferous one year after planting while annuals bloom abundantly after a few weeks of planting. Depending on the species and varieties, and according to the growing conditions (type of soil, climate, exposure, gardener’s experience, etc.), the rate of establishment will not be the same for all perennials. Take the concrete case of Dictamnus albus, which takes several years to establish but ultimately proves to be one of the perennials with the longest longevity.
• Perennial plants have specific cultural requirements even if some are very accommodating. It is crucial to take this into account to increase their lifespan. A plant suited to dry soil will quickly decline in poorly drained soil, or a shade plant will suffer in full sun.
• Not all perennial plants are hardy! Some are perennial in mild climates but are grown as annuals in cold climates because they do not withstand the rigours of winter.
• Most often, these plants are valued for their longevity and their ability to return each year, becoming more generous with minimal maintenance. They also offer a great diversity.

What to remember: a perennial plant takes longer to establish compared to an annual plant. It roots during the planting year, and it is only in the following season that it truly thickens and develops. A perennial plant in a bucket will not provide an immediate effect in a flowerbed, unlike an annual plant that will mature in a few weeks.

What is the lifespan of a perennial plant?

Perennial plants live for more than two years but they do not all have the same life expectancy. Indeed, they enter dormancy in winter (allowing them to withstand unfavourable climatic conditions) to resume their growth in the following spring. However, they can become exhausted over the years and sometimes disappear without warning. A perennial can live for a certain number of years (up to 60 years or more) without the gardener’s intervention, depending on the species and under optimal growing conditions.

Among perennial plants, we distinguish:

• short-lived perennials (3 to 5 years)

Some perennial plants have a relatively short life expectancy. Unlike biennials, they have the ability to flower for several years before disappearing. This is the case for foxgloves, linarias, gaillardias, columbines, or even hastate verbenas or Buenos Aires verbenas. With a few exceptions (for example: Digitalis ‘Glory of Roundway’ is sterile. It does not produce seeds; propagation occurs solely through division), these plants self-seed if conditions allow. However, it is possible and even advisable to collect seeds, divide, or propagate these plants to keep them in the garden.

• medium-lived perennials (5 to 20 years)

These perennial plants return each year for at least 5 years. This includes astilbes, monardas, delphiniums, lamiums, and rudbeckias.

• long-lived perennials (20 years and +)

These perennial plants have great longevity. This includes daylilies, hostas, peonies, lady’s mantle, bergenias, and elf flowers.

Check out our advice sheet: “20 durable perennials with a very long lifespan“.

List of plants and estimated lifespan

Here is a non-exhaustive list of plants, according to their average lifespan under optimal growing conditions and without intervention (division):