How to Plant, Grow, and Care for Agapanthus

Wondering if agapanthus might grow well in your garden? Looking for a little more information on this little-known niche plant? In this article, certified master gardener Liz Jaros dishes the dirt on this low-maintenance garden gem and gives you the information you need to plant some yourself.

A close-up of Agapanthus plants showcases their vibrant blue flowers with delicate petals, gracefully attached to sturdy stems. The lush Agapanthus plants create a beautiful and lively display, contributing to the overall garden's aesthetic.

A beautiful perennial with an attractive leaf structure and season-long interest, agapanthus is one of those plants that can really test a gardener’s identification skills. Happen upon some on a stroll through your neighbor’s yard or a visit to your local botanical garden, and it may take you a beat to accurately come up with the genus. 

Overview

A close-up of Agapanthus featuring mesmerizing blue flowers. The foreground highlights the intricate details of the blossoms. In the blurred background, hints of other flowers create a dreamy atmosphere, highlighting the main subject's stunning elegance.
Botanical Name Agapanthus
Family Amaryllidaceae
Genus Agapanthus
Native Area Southern Africa
Exposure Full sun
Height 1-5 feet tall
Watering Requirements Moderate
Soil Type Loamy to sandy
Pests Mealybugs, spider mites, snails and slugs
Diseases Root rot, gray mold, powdery mildew
Maintenance Low
Hardiness Zone 8-10

What is Agapanthus?

With long, strappy leaves, agapanthus resembles an iris (or a daylily or an ornamental grass). The flowers have a dome or globe shape like an allium (or a globe thistle or a milkweed). Its nickname (lily of the Nile) makes things even more confusing since agapanthus flowers resemble a miniature version of the traditional lily.

In fact, the genus is so close to so many others botanically that it’s been assigned and reassigned to several different plant groups before recently earning its own family, agapanthaceae.

Once you get to know this lovely plant, however, we’re sure you’ll never misidentify it again (and that you’re going to want to grow some in your own backyard). Read on for a detailed exploration of the agapanthus genus, including its characteristics, history, growing preferences, maintenance requirements, and problem areas. 

Characteristics

A close-up of an Agapanthus plant showcasing its vibrant blue flowers in full bloom, each delicate petal gracefully unfurling under the sun's warm embrace. The striking contrast against the blurred backdrop of other blossoms accentuates its beauty, drawing the viewer's gaze into its intricate details.
Many varieties of agapanthus are evergreen, retaining their color even through winter.

Hardy in zones 8-10, agapanthus is a tender, herbaceous perennial with a round arching habit. Its strappy leaves are dark green and glossy with a prominent midrib crease and a length averaging somewhere between one and two feet. Some have variegated leaves with white centers or margins. Many are evergreen and will hold their color throughout winter.

Agapanthus roots are tuberous and plants grow from the center outward as the rhizomes spread. Inflorescences are terminal and emerge as green bulb-shaped buds on thick, upright stems that float above the foliage. Flowering occurs at least once in summer and often repeats in regions with longer seasons. 

Blooms have a rounded umbel shape and contain 20 to 100 small, bell-shaped flowers. Each has six reflexive petals and a deep throat with a central stamen cluster. Coloring can be white to dark purple, and petal midribs are usually darker than their margins. 

History & Cultivation

A close-up reveals multiple Agapanthus flowers, their clustered blooms painting a scene of nature's artistry in shades of blue and white. Alongside the flowers, the Agapanthus leaves stand tall and verdant, adding a lush backdrop to the garden landscape where they're lovingly planted.
Agapanthus plants were believed to possess magical and medicinal properties.

The genus has a confusing taxonomic history. Once a monotypic family consisting of only one genus, Amaryllidaceae includes multiple species, and hundreds of cultivars. 

Despite its misleading nickname (Lily of the Nile), the Agapanthus genus is native to southern Africa rather than northeast Africa’s Nile River basin. Brought to Europe by African explorers in the late 1600s. The plant has medicinal purposes. Its parts were used to treat paralysis, heart disease, respiratory conditions, and a variety of other ailments, and its leaves were used as bandages.

Planting

You can plant agapanthus in a container, ideally in spring or fall. Hardy in zones 8-10, you can grow it in the ground year-round in warmer parts of the globe. In zones below 8, plant them when soil temperatures exceed 50 degrees Fahrenheit (10 degrees Celsius) and bring them in for winter. 

In the Ground

A close-up of Agapanthus flowers in full bloom, showcasing delicate petals in shades of blue and purple. The lush, green leaves surround the flowers, creating a harmonious balance. Planted in rich brown soil, the arrangement stands beside a neatly manicured green lawn, while a protective net adds a touch of structure on one side.
Install Agapanthus plants in a shallow trench, spacing them 12 to 18 inches apart.

Plant agapanthus 12 to 18 inches apart. Dig a shallow trench that’s roughly two inches deep and set rhizomes in the soil with their eyes or green shoots directed upward. Cover loosely with soil so that the top quarter of the rhizomes are slightly exposed.

In a Container

A close-up of an Agapanthus plant, its intricate flowers captured in exquisite detail, revealing their unique beauty. The lush leaves gracefully cascade in a large flower pot, set against the backdrop of a vibrant green grassy ground and a house in the distance. Bathed in direct sunlight, the plant thrives in its natural environment.
To prevent excessive foliage, avoid pots larger than 12 inches.

Select a well-draining pot that’s 10 to 12 inches wide to accommodate agapanthus’ mature width. Agapanthus blooms more prolifically with constricted roots, so anything larger than 12 inches might lead to a more foliage-heavy specimen. Fill your container with a fertile potting mix. Set rhizomes in a shallow trench that’s two inches deep and cover loosely with potting mix. 

Established Plants

A close-up reveals the intricate details of the Agapanthus plant, showcasing its captivating blue flowers. The delicate petals form a striking contrast against the lush green leaves, creating a harmonious display of nature's beauty. Placed within a garden, surrounded by verdant plants, it adds a touch of elegance to the outdoor landscape.
Backfill with soil or potting mix if you’re planting in a container.

If you’ve purchased a flowering agapanthus plant from a garden center or received one from a fellow gardener, dig a hole that’s just as deep and roughly twice as wide as the plant’s root mass. Set the root mass in your hole so that the plant’s crown sits just above the soil surface, and backfill with soil (or potting mix, if you’re planting in a container). 

How to Grow

Agapanthus plants are easy to grow and care for as long as you know what kind of species you have and your hardiness zone. Leave deciduous varieties in the ground where they are hardy or overwinter them in a cool, dark place in regions with cold winters. 

Evergreen varieties are particularly cold-sensitive. Bring them inside if temperatures are expected to dip below 50 degrees F (10 degrees C). Note that evergreen species will not go dormant like deciduous species but will cycle through their bloom periods like a houseplant, requiring sun and water year-round. 

When given a generous amount of natural light, rich soil, and good drainage, agapanthus plants can live for up to 10 years. Here’s a look at this unique plant’s specific growing requirements:

Light

A close-up of the Agapanthus, the enchanting flower has petals displaying rich and mesmerizing hue. Against a blurred background of green grasses, the Agapanthus stands out, creating a captivating composition that highlights the elegance of the bloom within its natural environment.
Ideally, select a location that receives a minimum of six hours of direct, unfiltered sunlight.

Agapanthus plants require full sun to flower fully and achieve firm, green, healthy foliage. Site them where they will receive at least six hours of direct, unfiltered light.

In regions with hot afternoon temperatures and scorching sun, choose a location that offers six hours in the cooler parts of the day. An east-facing bed with some afternoon shade is ideal. 

Water

A close-up unveils the intricate beauty of Agapanthus flowers, showcasing delicate petals in shades of blue and white. Surrounding them are vibrant green leaves, providing a lush backdrop. In the blurred background, a tropical rain creates a serene atmosphere with verdant lawns and trees.
Monitor local precipitation levels or use a rain gauge to ensure proper watering.

Water new plants about one inch per week while they are setting roots and adapting to a new location. Once established, reduce watering to about one-half inch per week. Use a rain gauge or monitor your local precipitation levels to make sure you’re providing enough but not too much water.

Direct supplemental irrigation at your plant’s roots and not its leaves or flowers. Use a soaker hose or a low, slow setting on your hose nozzle, and water in the morning if possible. This will give condensation on leaf surfaces a chance to evaporate throughout the day and discourage fungal conditions. 

Soil

A close-up captures the richness of brown fertile loam, teeming with nutrients essential for plant growth. Its finely textured composition promises fertility and abundance, making it an ideal substrate for cultivating a thriving and verdant garden or agricultural landscape.
This plant prefers well-draining, loamy soil but is adaptable to various soil conditions.

Agapanthus is tolerant of a wide variety of soil conditions but grows best in light, loamy soil that drains quickly. Evergreen species enjoy a little sand worked into the mix.

Container-grown agapanthus plants enjoy a light potting mix that’s slightly acidic. For both potted and in-ground plants, shoot for a pH level that’s somewhere between 5.5 and 6.5 for best results

Maintenance

Once its growing needs are met, caring for agapanthus is not difficult, and its maintenance will not demand too much of your time and attention. Gardeners in zones that occasionally but do not regularly freeze will likely have to think about this plant more than others, and gardeners below this plant’s zone 8 cutoff will have to think about overwintering. Outside of these concerns, maintaining agapanthus is fairly straightforward.

Mulch

A hand in white gardening gloves delicately holds a mulch of wood chips, showcasing the textured blend of bark and twigs. The wood chips, strewn on the ground, create a natural, earthy bed where they are carefully placed.
Choose from hardwood chips, composted yard waste, or straw for effective mulching.

A two to three-inch layer of organic mulch will protect agapanthus from cold winter temperatures while keeping its roots moist and discouraging puddles. It will also nourish the soil and decompose over time.

Hardwood chips, composted yard waste, leaf litter, and straw are all good choices for mulching agapanthus. Pull mulch away from plant crowns in spring when the sun begins to warm the soil.

Fertilizing

A close-up of a hand reveals a vivid blue NPK-balanced chemical fertilizer. The granular composition of the fertilizer emanates a nutrient-rich formula designed to enhance plant growth. The hand holds the fertilizer, highlighting its essential role in nurturing vibrant, healthy plants.
Apply fertilizer in early spring.

This plant will benefit from a fertilizer application in early spring and again two months later when flowering is about to begin. Choose a balanced granular fertilizer with an even NPK ratio (10-10-10) or one with a slightly higher phosphorus content (5-10-10) if you want to encourage flowers over foliage. Apply as directed and water immediately.

Deadheading

A vibrant cluster of Agapanthus flowers adorning slender stems in a garden. The intricate bloom showcases hues of blue and white, capturing the essence of nature's beauty. Lush green leaves surround, creating a picturesque scene of botanical elegance.
To deadhead spent agapanthus flowers, use a clean, sharp pruning tool.

Depending on where you live, agapanthus will flower at least once in early summer for a period of about three weeks. In warmer regions, a second wave can be expected later in summer, especially if spent blooms are deadheaded promptly

Removing faded flowers will tell roots that seeds have not been spread and reproduction has failed. This will signal them to send up more blooms in an effort to create more seeds and, thus, result in more flowers. Deadhead spent agapanthus flowers by cutting their stems down to the base with a clean, sharp pruning tool. 

Pruning/Cutback

The captivating bloom of an Agapanthus plant, revealing delicate petals in shades of blue. The background is adorned with lush green leaves, providing a stunning contrast to the intricate floral display.
For evergreen agapanthus, pruning is unnecessary unless there are signs of health issues.

Agapanthus does not need pruning throughout the season. If brown or yellow leaves appear, they can be snipped off to discourage disease, but healthy, green foliage must be left in place until the end of the season. Evergreen agapanthus should not be cut back at all unless there is a health problem. 

When the leaves of a deciduous agapanthus plant turn brown in fall, this is a signal that they are entering dormancy and are ready to be cut back. Using clean, sharp bypass pruners or loppers, cut leaves down to about three inches above the plant’s crown. This will tell the roots to nourish next year’s plants rather than this one’s. 

Overwintering

A close-up of a vibrant Agapanthus flower showcasing delicate blue petals nestled in the green stem. The blurred backdrop reveals towering trees, creating a natural contrast. Bathed in direct sunlight, the intricate details of the bloom are highlighted, evoking a sense of beauty and serenity.
In case of limited space, rhizomes can be dug up, cleaned, and wrapped in paper.

Plants that are hardy can be left in the ground after being cut back as long as temperatures are expected to remain above 50 degrees (10°C). Those grown in pots and those grown in regions where the genus is not hardy (below zone 8) can be stored in a cool, dark room or garage that doesn’t freeze. Rhizomes can also be dug up, cleaned off, and wrapped in paper if storage space is limited.  

Division

A close-up of multiple Agapanthus plants showcasing their captivating flowers, each bloom contributing to a burst of blue color. The leaves are lush and green, creating a dynamic contrast against a restaurant setting with tables and chairs. Beyond the plants, a walkable area beckons, creating a harmonious urban oasis.
It’s crucial to divide these plants approximately every three years.

Although agapanthus plants flower prolifically when roots are densely packed, they do require division every three years or so to keep their upright habit. To perform this basic maintenance task, follow these steps:

  1. Carefully lift the entire plant from the ground or its container. 
  2. Lay it flat on a tarp or hard surface and brush off the dirt so rhizomes are somewhat exposed.
  3. Use a knife or flat garden shovel to slice the root mass into equal sections or break off individual rhizomes with your hands.
  4. In each new section, be sure to include some rhizomes (the fleshy potato part), some fibrous root hairs, and some eyes (green shoots or brown bumps). 
  5. Replant as you would a new agapanthus plant.  

Propagation

A close-up reveals the enchanting beauty of Agapanthus plants, showcasing vibrant blue flowers gracefully adorning their slender stems. The lush green leaves surrounding the blossoms provide a verdant backdrop, creating a visually pleasing contrast. A charming pathway runs through the middle, inviting exploration.
The most effective technique for multiplying agapanthus plants is division.

Although seeds can be collected from faded flowers and planted directly in the soil, this is not the recommended method for propagating agapanthus plants. Not only do seeds take several years to establish, but new plants will not likely resemble the original since most nursery-sold agapanthus plants are hybrids. 

Division is by far the most effective method for turning one agapanthus plant into several, and since the process is asexual, the new plant will be an exact clone of its parent.  

Varieties

It’s unlikely you will purchase an agapanthus plant in your local garden center that hails from a true, singular species. These exist in the wilds of southern Africa but not anywhere else in the world. The genus crosses easily with itself, and the ornamental cultivars are usually derived from blended species. 

For this reason, most plant tags will not reference a specific agapanthus species at all and will just cite the genus and cultivar. You will also frequently see plants in this group generically referred to as an ‘African lily.’ 

Be sure to check hardiness zones and plant descriptions to determine if you’re getting a deciduous or evergreen variety. Here’s a look at some of the most common agapanthus cultivars and a brief description of each.

Brilliant Blue

A close-up of the Brilliant Blue Agapanthus variety, the stunning flowers elegantly emerge from their stems, displaying a captivating blue hue. In the blurred background, lush green leaves contribute to a lush environment, enhancing the overall allure of this enchanting botanical scene.
This dwarf variety yields approximately 100 flowers each summer.

This deciduous variety has loose umbels of violet-blue, trumpet-shaped flowers with dark midribs. At maturity, each plant produces roughly 100 flowers per summer. Considered a dwarf, ‘Brilliant Blue’ maxes out at 18 inches. It’s considered semi-evergreen and hardy in zones 8-11. 

Polar Ice

A close-up of the Polar Ice Agapanthus variety showcases its pristine white flower cluster. The delicate blooms stand out against the clear blue sky in the background, creating a stunning contrast and highlighting the natural beauty of this elegant plant.
Featuring snow-white flower clusters, this cheerful agapanthus cultivar grows up to three feet tall.

Blooming prolifically from mid-summer to early fall, this bright and cheerful agapanthus cultivar features snow-white flower clusters and grows up to three feet tall. The leaves are upright and bright green, arching slightly at their peaks. This one tolerates a bit more chill and can survive without fuss in zones 8-11. 

Fireworks

A close-up of the Fireworks Agapanthus variety with its vibrant light blue flowers that burst forth in a spectacular display. The lush green leaves add depth and texture, while the plant thrives in the brown earth, adorned with small brown wood chips for a charming natural touch.
This plant is named for its resemblance to a festive burst of sparks in the night sky.

This compact, evergreen cultivar earns its name for resembling a festive burst of sparks in the night sky. The flowers are two-toned and trumpet-shaped, with lavender throats that transition to white at the petal tips. Maxing out at two feet tall, ‘Fireworks’ remains green year round and is hardy in zones 8-11. 

Common Problems

When properly planted and maintained, agapanthus plants are known for being highly resistant to pests and diseases. There are a few to watch out for, however. Here’s a quick look:

Diseases

 A close-up of Agapanthus plant stems, exhibiting intricate patterns of green with hints of yellow. Some stems show signs of potential disease, with discoloration and irregular growth, emphasizing the need for careful observation and proactive plant care.
Root rot, a fungal condition, is the primary disease affecting agapanthus.

The diseases that most affect agapanthus are all fungal in nature, and root rot tops the list. Brought on by poor drainage, overzealous watering practices, and/or excessive precipitation, root rot is a fungal condition that kills a plant from the ground up. Characterized by wilted or yellowing leaves, mushy rhizomes, and a foul smell, root rot is almost always fatal, and agapanthus plants afflicted with this disease should be destroyed.

Gray mold is also brought on by excessive moisture or improper drainage. Symptoms of this fungus include a fuzzy, gray covering on leaves and stems. You might also notice a ring in the soil around your plant’s crown. If you suspect gray mold, snip away the affected plant parts promptly, and it has a good chance of recovering fully. 

Powdery mildew is a mostly aesthetic fungal condition brought on by excess moisture and inadequate airflow. Symptoms include a dark gray or black coating on leaves, stems, and possibly flowers. Look for it after cool, wet periods and remove affected tissue from the garden. Powdery mildew is not life-threatening, but it can overwinter in the soil, so keep things tidy to prevent an ongoing problem. 

Insects & Critters

A close-up of Agapanthus plant showcasing vibrant blue flowers. The blossoms, with delicate petals and visible stamen, contrast beautifully against the lush greenery. In the blurred background, branches create a subtle backdrop, and a bee can be seen pollinating one of the flowers, adding a dynamic touch to the scene.
The most effective way to confirm their presence is by using a flashlight after dark.

If you’re noticing cotton-like masses on your agapanthus plant’s leaves or stems, you may have a mealybug infestation. These sap-sucking insects drain the nutrients from plant tissue and leave a sticky excrement behind that attracts ants. 

Spider mites will produce a white, stringy webbing that’s slightly less dense than mealybugs, and you may notice white puncture marks on leaf tissue. They will also leave a sooty residue that attracts other insects and diseases. 

Look for chewed leaf margins and slimy trails on their undersides to indicate a problem with snails or slugs. Since they are most active at night, particularly during cool, wet periods, the best way to confirm their presence is with a flashlight after dark. 

The solution for dealing with insects that attack your agapanthus plants is generally the same for all. A regular, hard blast from the hose and/or manual removal are going to be your best weapons. Slugs and snails can be deterred with beer traps or bait you can purchase at your local hardware store.

Frequently Asked Questions

Is agapanthus toxic to pets?

Yes, ingesting agapanthus may cause mild gastrointestinal symptoms in small mammals.

Can agapanthus change color?

No, a change in bloom color from one season to the next is most likely the result of hybrid seeds germinating in the vicinity of the mother plant.

What is the origin of the word agapanthus?

It is derived from the Greek word for love or lovely (agape) and the word for flower (anthos).

Final Thoughts

Though it’s not as popular as many of its strappy, ornamental peers, agapanthus is a genus worth getting to know. With leaves that hold their shape and color year-round and a particularly long, floriferous blooming period, it really delivers in the garden.

Easy to care for and propagate, it thrives in a container and pairs well with many perennial color families. Protect it from freezing temperatures, and it should brighten your landscape reliably for many years to come. 

SHARE THIS POST
A close-up reveals the delicate beauty of petite deutzia flowers, showcasing five exquisite purple petals. Gracefully positioned behind the blooms, the ovate green leaves provide a verdant backdrop, enhancing the overall charm of this floral composition.

Shrubs

How to Plant, Grow, and Care for Deutzia

Deutzias are a genus of deciduous shrubs offering the sought-after combination of beautiful flowers and a low-maintenance lifestyle. Join Briana Yablonski as she covers the characteristics and care of deutzia plants.

Close-up of a flowering Cercis canadensis tree, one of the famous native flowering trees, against a blurred green background. The tree features small, heart-shaped leaves of bright green color. It produces clusters of small, vibrant pink to lavender-pink flowers, creating a striking visual display.

Trees

21 North American Native Flowering Trees

If you think you have to choose between the benefits of native plants and the beauty of flowering trees, think again! Briana Yablonski will cover 21 North American native flowering trees you can grow at home.

A collection of potted plants, carefully arranged to create a lively display. The crimson, green, pink, and purple hues of the leaves interweave, forming a visually captivating composition that adds a burst of color to any space.

Ornamental Gardens

27 Colorful Plants for Shade Gardens

Color is not hard to find in a shady garden. You just have to know where to look. This list of 27 plants will give you the best choices for glorious foliage and pretty flowers, some ground covers, and some tall, bushy types, so there are good options for any look. The shade is the perfect spot to start a wild or meadow garden and make use of the many charming plants that you can grow.

A close-up of a cluster of ripe hardy kiwi berries hanging from a vine. The berries are smooth-skinned and green, with a few fuzzy red hairs at the blossom end. They appear almost jewel-like against the backdrop of dark green leaves, hinting at the juicy sweetness within.

Fruits

How to Plant, Grow, and Care For Hardy Kiwi

While many people think of kiwis as tropical plants, hardy kiwis make a great addition to many temperate gardens. Join plant expert Briana Yablonski as she shares how to plant, care for, and harvest for this unique vining plant.

Close-up of a blooming rosie o' day alyssum on a blurred green background. This variety forms low mounds of lush foliage adorned with clusters of tiny, four-petaled flowers. The blossoms feature a soft pink hue, creating a lovely contrast against the plant's dark green leaves.

Flowers

How to Plant, Grow, and Care for ‘Rosie O’Day’ Sweet Alyssum

Need to fill gaps in your garden or add a pop of color to retaining walls? ‘Rosie O'Day’ Sweet Alyssum is a low-growing, beautiful ground cover that boasts shades of pink and magenta. Join organic farmer Jenna Rich as she shares how to plant, grow, and care for this cheerful, pink flowering perennial.