With spherical clusters of flowers rising above stately arched foliage, agapanthus is an eye-catching addition to perennial borders and patio planters. The blooms, in shades of blue and violet, or white depending on the variety, are held aloft on strong, slender stems, making them as stunning in bouquets as they are outdoors swaying in the breeze.
About Agapanthus
The elegant, trumpet-shaped blooms of agapanthus resemble lily flowers, giving rise to the common names, which include lily of the Nile, African lily, and blue African lily. The blooms are also attractive to pollinators, including butterflies and hummingbirds. The strappy forms an attractive garden backdrop even when plants aren’t in bloom.
Though there are several species in the Agapanthus genus, most commonly available types are hybrids. Hardiness, mature plant size, and flower color varies so read plant descriptions carefully. Some types are evergreen in mild climates; others are deciduous and suitable for more temperate locations. Some are small, reaching just 12” high, making them especially suited to containers; others grow to a dramatic 5’ in height. Most bloom from early summer into fall. In some climates the plant readily self-sows and spreads, to the extent that some gardeners consider it a weed.
Note: Agapanthus rhizomes (roots), leaves, and sap are toxic if ingested, and the sap can irritate skin. Keep plants away from children and pets and wear gloves when handling.
Growing Zones for Agapanthus
Evergreen agapanthus varieties are generally hardy in USDA Hardiness Zones 8-11. Deciduous types are somewhat hardier, thriving down to zone 7, or even to zone 6 with winter protection.
In regions outside their hardiness range, the plants are best grown in containers and brought indoors over the winter. Evergreen varieties can be kept as a houseplant; deciduous varieties do well when allowed to go dormant indoors for a few months.
Choosing a Site to Grow Agapanthus
Agapanthus thrives in part to full sun. In hot, sunny climates the plants appreciate some shade during the warmest part of the day. They like rich, well-drained soil with plenty of organic matter. Avoid saturated soil, which can quickly lead to root rot.
The plants create an especially stunning display when grown in masses or drifts. Large varieties anchor the back of a perennial garden, while smaller ones are ideal for flanking an entryway or bordering a driveway or walkway.
The plants thrive in containers, making them ideal for porches and patios where you can enjoy the blooms up close.
Planting Instructions for Agapanthus
Although agapanthus can be grown from seed, it takes several years for plants to grow large enough to bloom. Seed-grown plants vary widely due to the plant’s long history of hybridization.
Most gardeners start with purchased plants, divisions, or bare-root rhizomes (fleshy rootlike structures), which yield flowering plants in just a season or two.
Loosen soil to a depth of 1’ and add plenty of compost and/or a granular, slow-release fertilizer. Set container-grown plants in the ground at the same level they were in their pots. If planting rhizomes, place them pointy side up, root side down, and cover the top with 1” to 2” of soil. Space plants according to their mature size. Small varieties can be planted 12” apart; large varieties should be spaced at least 24” apart. If growing in containers, start with a pot that’s at least 12” in diameter. Water plants well after planting.
Mulch in-ground plants with an organic fertilizer, such as shredded bark or pine straw, to discourage weeds and conserve soil moisture.
Fertilizer for Agapanthus
Feed in early spring and then every two to three weeks through midsummer. Avoid high nitrogen fertilizers, which encourage abundant foliage at the expense of flowers. Apply a layer of compost beneath plants each spring to provide nutrients and boost soil health.
Agapanthus Pests and Problems
Agapanthus is generally resistant to pests and diseases, and deer and rabbits avoid them. Occasionally, fungal diseases will damage foliage; remove affected leaves and avoid overhead watering to help keep diseases in check.
Ongoing Care for Agapanthus
Although relatively drought-tolerant once mature, agapanthus appreciates regular watering during active growth, as well as in late summer when plants are forming buds for next season’s blooms.
Remove faded flowers to prevent seed production. For deciduous types, leave the foliage until it dies back naturally so it can replenish the energy stored in the rhizomes. Divide the plant every three years or so.
In regions at the cold end of the plant’s hardiness zone, apply a winter mulch to protect the roots. In colder regions, grow the plants in pots and overwinter them indoors. Treat evergreen types as a houseplant; allow deciduous types to go dormant and store in a cool, dark spot.
