Wondering what is a perennial plant? This is a very common question for anyone learning to garden or getting back into it after a break.
A perennial is a plant that grows back every year. Perennial species have an expected lifespan of over two years. A plant must live for a minimum of three years to be considered a true perennial.
Perennial plants typically have a period of dormancy each year (often during the winter). Perennials survive over winter, whereas annual plants generally do not. Many popular perennials are herbaceous, meaning the aboveground portion of the plant dies back to the ground in the fall, and then new foliage sprouts from the plant’s roots in the spring.
Perennials are common in landscaping because they come back each year. The starter plants can be a bit pricey, but you only have to buy them once. Annuals, on the other hand, have to be replanted each year. Annuals and biennials, however, typically have a longer blooming season than perennial flowers.
Read on to learn all about perennial plants!
What is a perennial plant?
Perennial plants are plants that live for more than two years. Another way to say this is that perennials are plants that should live for three years or more.
Plants that return from their roost the third year after planting are perennials. They go through more than two growing seasons without the gardener having to replace it. They are described as long-lived plants that hibernate and return each new year on their own.
When gardeners refer to perennials, they are usually referring to flowering herbaceous perennial plants that are grown as ornamentals, either for curb appeal or in a bouquet cutting garden. That said, there are also other types of perennials, including perennial vegetables like asparagus and even perennial fruits like strawberries. Fortunately, perennials are easy to grow, even for beginner gardeners.
Characteristics of a perennial plant
When you hear the term perennials, you may also hear herbaceous perennials. This means that these plants are nonwoody plants whose above-ground parts die each year. Herbaceous perennials die up top but remain alive all winter below the surface.
The only way they survive is by the extensive root systems they have to keep them alive through the winter. These root systems are comprised of bulbs, corms, rhizomes, tubers, and other root systems. These amazing systems are what help them survive cold winters and repeat their life cycle each season.
Some perennials are evergreen and keep their leaves all year long. This is common in tropical climates, where it is warm all year.
Perennials usually cost more at the garden center because they must be cared for year-round rather than just started from seed in the spring. Many are also propagated by dividing up an existing plant rather than from seeds. The division process limits the output (until you get into tissue culture…).
“Perennials grace our gardens year after year with their variety of brilliant colors and unique foliage forms. After a few years in the garden, these perennials may start to produce smaller blooms, develop a ‘bald spot’ at the center of their crown, or require staking to prevent their stems from falling over. All of these are signs that it is time to divide.”Univeristy of Minnesota Extension, How and when to divide perennials
Popular perennial flowers and plants
There are so many beautiful perennials to choose from, but here are some gardener favorites! Add these to your garden plants for tons of beauty and greenery all year.
Here are some examples of perennial plants:
- Coral bells
- Bleeding heart
- Shasta daisy
- Canna lily
Pay attention to the growing season of each of your perennials and read the tag that comes with each bulb or pre-potted plant. The hardiness zones of each plant makes a difference as well, so note that from each tag.
Sub-categories of perennial plants
Perennial plants can be subdivided into smaller categories. A common subclassification is hardy and tender perennials. In general, hardy perennials can withstand their roots being frozen, while tender perennials cannot.
Hardy perennials have tough root systems that can survive winter. Each type of perennial has its own degree of cold tolerance, which is usually indicated on the tag.
For instance, the popular pink peony cultivar ‘Sarah Bernhardt’ (Paeonia lactiflora ‘Sarah Bernhardt’) is listed as USDA Zones 4-8 in terms of growing zones/cold hardiness. That means that this plant can be grown outdoors year-round in areas as cold as Zone 4, where winter temperatures can reach -30 °F (-34°C).
Other common hardy perennials include hostas, tulips, irises, bleeding heart, primrose, bee balm, catmint, coneflower, delphinium, hellebore, and hardy hibiscus.
In contrast, the popular light pink dahlia cultivar ‘Cafe au Lait’ is listed as USDA Zones 8-10 in terms of growing zones. That means that this plant can typically only be grown outdoors in areas down to Zone 8, where winter temperatures only get down to about 10°F (-12°C). Gardeners that live anywhere it gets colder than 10°F usually dig up their dahlia roots in the fall and store them indoors until spring.
Other common tender perennials include gladiolus, canna lily, begonia, elephant ears, taro, caladium, and Spanish lavender.
Pros and cons of planting perennials
Perennials and annuals have great characteristics depending on the needs of the gardener. Here are some pros and cons of planting perennials in your garden.
- Perennials are great for gardeners who want to plant greenery and then not touch it much. Perennials come back each year, making less labor for the gardener.
- These plants are perfect for the soil and help with aeration and water filtration. Erosion tends to be reduced where perennial plants are placed.
- Perennials tend to have a long harvest time, making them great plants for full seasons.
- They require less maintenance and can usually withstand harsh conditions compared to annuals.
- Perennial plants make great landscape plants because they remain full for longer periods during the year.
- They sometimes take longer to yield blooms. Some don’t bloom in their first season, and you have to wait a few years to experience their full beauty.
- They usually have a shorter blooming duration than annual plants. While this doesn’t matter much for foliage perennials like hostas, it can make the more fussy perennials like delphiniums seem like quite a lot of work for a very short season of blooms.
- Perennials are often susceptible to disease and may require more treatment in this area.
- They also require more space in your garden, so plan for larger planting spots.
Overall, perennial plants are great options for any garden because they require minimal maintenance, and they won’t have to be replanted each year. Plant them with a few annuals, and you will have a full, lush garden season after season.
Tips for gardening with perennials
The great thing about perennial species is that they are tough and hardy plants. They aren’t as fussy as other plants and require minimal maintenance. The best time to plant perennials is after the last winter frost or anything up until fall.
If you are transplanting a perennial, dig a hole that is twice as large as the root system. Just don’t dig the hole any deeper than the soil in the plant pot. This gives your plant plenty of space to spread out once planted. Fill it with soil and let the plant do the rest of the work.
To make your life easier, group plants with similar watering requirements together. You won’t have to overthink when and how much to water each plant if they are grouped systematically. Plant perennials with plenty of space between one another and lots of room to grow, as many get fairly large.
Planting perennial bulbs
Plant your perennial bulbs based on when they will bloom. If you have a springtime variety, plant your bulbs in the early fall. This way, they are ready to bloom in spring. Similarly, if you have summer bulbs, plant them in the early spring. Be sure to do this once all frost has passed in your area.
Caring for your perennials
Perennials require a little bit of maintenance when it comes to deadheading blooms. By cutting off spent blooms, you will allow new growth in the flowering season. Apply weed preventer and a good fertilizer to encourage strong plant growth.
Water your perennial plants at the base of the plant. Avoid watering the leaves and aim the water at the soil and root systems. Evergreen perennials will especially appreciate this, so their leaves don’t wither and obtain a disease.
Whether you plant annuals or perennials in your garden, you will have foliage year-round. The life cycle of perennials makes garden growth so easy. Growing perennials is fairly simple and straightforward and a great place to start for new gardeners. Grab some of your favorite herbaceous perennials at the local nursery and add them to your garden this year.
FAQs about perennial plants
What is a perennial plant?
A perennial plant is a type of plant that lives for more than two years. Perennial plants typically live for a minimum of three years, giving them a longer expected lifespan than annual plants or biennial plants.
How long do perennial plants live?
The lifespan of a perennial plant can vary widely, with some species living for three years before they decline and others thriving for decades. Short-lived perennials like delphinium may need to be replaced every 3-5 years, while long-lived perennials like peony can be passed down through generations.
How do perennial plants differ from annual plants?
Perennial plants differ from annual plants in that they can live for many years, while annual plants have an expected lifespan of under one year. Perennial plants typically have a dormant period during the winter, during which they lose their leaves and become inactive. Annual plants, on the other hand, do not fall into dormancy and they need to be replanted each year.
Can perennial plants be grown indoors?
While some perennial plants can be grown indoors, many are better suited to outdoor growing. Perennial plants that require a lot of sunlight may not thrive indoors. However, there are some perennials that are well-suited to being grown as houseplants, such as ferns, some succulents, and many tropical plants that tolerate low-light conditions.