Solving the Mystery: Is Purple Fountain Grass a Perennial or Annual?


With so many ornamental grasses out there, purple fountain grass – Pennisetum setaceum ‘Rubrum’ – is likely the most popular, and it is considered to be a tender perennial. It offers burgundy or purple foliage with fuzzy and soft blooms followed by purplish seed heads. It makes a bold statement within the garden, either on its own or with other plants. You’re going to find it very easy to grow purple fountain grass, and there’s little maintenance.

Therefore, this ornamental grass can’t survive through the cold weather, and it’s hardy in the warmer zones, such as 7, 8, and 9. Therefore, when planting purple fountain grass, consider this before you do it so that it returns each year. Often, cooler regions treat it like an annual.

It’s still possible to enjoy the plant every year when you put it in containers and bring it inside for the winter. You can also cut it back to about three inches and put it in a cool and sunny area of the house. Alternatively, it’s possible to put it in the basement.

Just make sure that you keep the purple fountain grass moist and water it once a month or so. When the freezing weather has gone away, and early spring comes around, set your beautiful purple fountain grass back outside.

Characteristics of Purple Fountain Grass


Purple Fountain Grass, also known by its scientific name Pennisetum setaceum ‘Rubrum’, is a popular ornamental grass that is prized for its striking purple foliage. Its leaves are long and slender, and can range in color from green to deep burgundy, depending on the plant’s maturity and growing conditions. The grass also produces tall, feathery plumes that can reach up to two feet in height, adding texture and movement to any garden.

Growing Habits

Purple Fountain Grass is a warm-season grass that thrives in hot, sunny conditions. It’s native to tropical and subtropical regions of Africa, and is well-suited to growing in USDA hardiness zones 8-11. The grass is relatively easy to grow, and prefers well-drained soil that is kept evenly moist. It can also tolerate a range of soil types, from sandy to loamy.


Now, onto the big question: is Purple Fountain Grass a perennial or an annual? The answer is… it depends.

Understanding Perennial Plants

Definition of a Perennial Plant

As we mentioned earlier, a perennial plant is a plant that lives for more than two years. In the case of Purple Fountain Grass, this means that the plant should technically be able to survive for more than two growing seasons.

Comparison with Annual and Biennial Plants

Annual plants complete their entire life cycle (from seed to seed) in a single growing season. They typically grow quickly and produce abundant flowers or fruit, but do not survive through the winter.

Biennial plants, on the other hand, take two growing seasons to complete their life cycle. They grow foliage in their first year, and then produce flowers and fruit in their second year. After that, they usually die off.

Perennial plants, as we mentioned earlier, can survive through multiple growing seasons. They often take longer to mature than annual or biennial plants, but can provide years of enjoyment in the garden.

Factors that Affect Perennialism

There are several factors that can affect whether a plant is able to survive as a perennial. These include:

  • Climate: Some plants are better suited to certain climates than others. For example, a plant that is adapted to hot, dry conditions may not survive in a cold, wet climate.
  • Soil: Soil quality can also play a role in a plant’s ability to survive as a perennial. Plants that are adapted to nutrient-poor soils may struggle in soils that are too rich.
  • Growing conditions: The way a plant is grown can also affect its longevity. Plants that are well-cared for and given optimal growing conditions are more likely to survive as perennials than plants that are neglected.

Perennial or Annual

Now, let’s take a closer look at whether Purple Fountain Grass is a perennial or an annual.

Evidence Supporting Perennialism

There is evidence to suggest that Purple Fountain Grass can survive as a perennial in certain growing conditions. For example, in its native habitat of tropical and subtropical Africa, the grass is known to be a long-lived perennial. It’s also been reported to survive as a perennial in areas with mild winters, such as parts of California and Florida.

In addition, some gardeners have reported successfully overwintering Purple Fountain Grass in colder climates by providing the plant with adequate protection, such as mulching or covering with a frost blanket.

Evidence Supporting Annualism

On the other hand, there is also evidence to suggest that Purple Fountain Grass is best grown as an annual. In colder climates, the plant may not survive the winter and will need to be replanted each year. In addition, even in milder climates, the plant may begin to decline after a few years of growth, and may need to be replaced.

Another factor to consider is that Purple Fountain Grass is not a true perennial, in the sense that it does not grow back from the same roots year after year. Instead, it grows from seed, which means that even if the plant does survive the winter, it may not produce the same characteristics as the previous year’s plant.

Purple Fountain Grass

Benefits of Perennial Plants

Whether or not Purple Fountain Grass is a true perennial, there are many benefits to growing perennial plants in your garden. Here are just a few:

LongevityPerennial plants can provide years of enjoyment in the garden, offering consistent color and texture.
Cost-effectivenessOnce established, perennials require less maintenance and do not need to be replanted each year, saving time and money.
Environmental BenefitsPerennials help reduce soil erosion, improve soil health, and provide habitat for beneficial insects and wildlife.
Low MaintenanceMany perennials are hardy and require minimal care once established, making them a convenient choice for busy gardeners.
Seasonal InterestPerennials often have varying bloom times, providing a succession of colors and textures throughout the growing season.
Naturalizing AbilitySome perennials have the ability to self-propagate and spread, filling in gaps in the garden and creating a lush landscape.
VersatilityPerennials come in a wide range of sizes, shapes, and colors, offering endless options for garden design and personal expression.
Pollinator AttractionMany perennial flowers are attractive to pollinators like bees and butterflies, contributing to a healthy ecosystem.
Drought ToleranceSome perennial plants have adapted to survive in dry conditions, requiring less water and making them suitable for xeriscaping.
Timeless AppealPerennials have a timeless charm and can create a sense of continuity in the garden, improving its overall aesthetic.

Growing the Purple Grass

Purple fountain grass is a drought-tolerant plant and works well in warmer zones. It’s easy to maintain, and you’re going to like that you can plant it anytime. Spring is often the right choice for planting. The plant has to be put in a sunny spot, and well-draining soil is a must!

Mature plants can get about four feet tall and as wide as that. Give them enough room in the garden and keep other plants growing about 3 to 5 feet apart. You should dig a hole that’s deep and wide enough for the roots and give the purple fountain grass a thorough drink.

Caring for the Purple Fountain Grass

It’s easy to care for the purple fountain grass, and most gardeners like it for many reasons. Consider watering once a week or every other week when it’s in the garden. While it’s not required, it’s possible to give it an annual feeding of a balanced and slow-release fertilizer in the spring to stimulate new growth.

The right time to cut it back is in the fall before you bring it indoors. You may also find that if you leave it outside in warmer climates, it’s possible to bring it in during late winter. Growing is simple, and the care isn’t that hard, so this beautiful plant can bring happiness throughout the year.


So, is Purple Fountain Grass a perennial or an annual? The answer is not straightforward, and depends on a variety of factors, including growing conditions and climate. While the plant may survive as a perennial in certain areas, it’s generally best grown as an annual in colder climates.

Regardless of its perennial status, Purple Fountain Grass remains a popular choice for gardeners looking to add color and texture to their gardens. And whether you prefer to grow perennials, annuals, or a combination of both, there are many benefits to be had from cultivating a beautiful and sustainable garden.

Rachel Lean
Rachel Lean

Adventurer, loving nature and plants, particularly Pampas Grass. Happy to share with other people the knowledge that I accumulated on the journey of my life.