Agapanthus, also called lily of the Nile or African lily, produces tall stems topped with globes of blue, violet or white trumpet flowers from early to late summer. It is tough, drought tolerant once established, and happy in both garden beds and containers. Getting it to bloom reliably comes down to three things: choosing the right type for your climate, giving it plenty of sun, and resisting the urge to divide or over-pot it. Here is how to plant and care for agapanthus anywhere in the US, from frost-free coastal gardens to cold-winter patios.
In this guide
Key Takeaways
- Evergreen agapanthus is generally hardy in USDA zones 8–11; many deciduous types and hybrids handle zones 6 or 7 with mulch.
- Give it full sun (6+ hours) for best flowering; light afternoon shade is fine in hot inland areas.
- Plant crowns about 1–2 inches below the soil surface in well-drained soil, 12–24 inches apart.
- Agapanthus blooms best slightly crowded; do not divide more often than every 4–6 years.
- In cold zones, grow it in pots and overwinter in a cool, frost-free garage or basement.
Agapanthus Basics
Agapanthus grows from thick, fleshy roots attached to a short rhizome, forming clumps of strap-shaped leaves. Flower stalks rise well above the foliage, from about 18 inches on dwarf types to 4 feet or more on large cultivars. The plants are native to southern Africa, which explains their love of sun, heat and good drainage, and their tolerance of dry spells.
Evergreen vs. deciduous types
The most important choice is whether your agapanthus is evergreen or deciduous, because it determines hardiness.
| Type | Typical hardiness | Foliage | Best use |
|---|---|---|---|
| Evergreen (Agapanthus praecox, A. africanus and hybrids) | Zones 8–11; some only 9–11 | Wide leaves year-round | Mild-winter gardens in CA, Gulf Coast, Southeast; pots elsewhere |
| Deciduous (A. campanulatus, A. inapertus and hybrids) | Zones 6/7–10 depending on cultivar | Narrower leaves that die back in fall | Mid-Atlantic, Pacific Northwest, sheltered spots further north |
| Hardy hybrid series | Often zones 6/7–10, check the label | Mostly deciduous | Gardeners pushing the cold limit |
Popular cultivars include ‘Peter Pan’ (dwarf, evergreen, blue), ‘Storm Cloud’ (deep violet-blue), ‘Blue Yonder’, ‘Queen Mum’ (white with blue bases) and ‘Bressingham Blue’ (a deciduous, hardier choice). Hardiness ratings vary between nurseries, so trust the specific label and lean toward the conservative number if you garden at the edge of a zone. If you are not sure how a plant behaves in winter, our explainer on hardy vs. tender perennials covers the difference.
When to Plant
- Zones 9–11: plant potted agapanthus in fall or early spring, when roots can settle before summer heat. Avoid planting in the hottest months if you cannot water regularly.
- Zones 7–8: plant in spring after the last frost so the clump has a full season to establish before its first winter.
- Zones 6 and colder: plant hardy deciduous types in spring in a warm, sheltered spot, or grow any type in containers and move them inside for winter.
Agapanthus is usually sold as potted nursery plants or as bare-root divisions. Bare-root plants should be planted promptly; if you must wait, keep the roots lightly moist and cool.
Where to Plant
Sun: full sun gives the most flowers. In very hot inland climates such as the desert Southwest or interior California valleys, light afternoon shade prevents leaf scorch without hurting bloom much. In heavy shade, plants stay leafy and flower poorly.
Soil: agapanthus tolerates sand, loam and amended clay, but not waterlogged ground. The fleshy roots rot in soil that stays wet, especially in winter. If water stands after rain, plant on a slight mound or in a raised bed, or work in compost and fine bark to improve structure. A pH from slightly acidic to neutral (about 6.0–7.0) is ideal.
Placement: agapanthus is excellent along paths and driveways, at the front of borders, on dry banks, and in coastal gardens since it handles wind and some salt spray. Pair it with other sun lovers; see our list of full sun perennials for companions such as lavender, salvia, daylily and ornamental grasses.
How to Plant Agapanthus in the Ground
- Dig a hole about twice as wide as the root mass and just as deep.
- Loosen the soil at the bottom and mix in a few handfuls of compost if your soil is poor or heavy.
- Set the plant so the crown, where leaves meet roots, ends up about 1–2 inches below the soil surface. Container plants go in at the same depth they grew in the pot. In colder zones, planting slightly deeper, around 2–3 inches, gives the crown extra protection.
- Space small cultivars about 12 inches apart and large ones 18–24 inches apart. Closer spacing fills in faster, and agapanthus does not mind being snug.
- Backfill, firm gently, and water deeply to settle the soil.
- Mulch with 2 inches of shredded bark or similar, keeping it a couple of inches off the crown.
Growing Agapanthus in Pots
Containers are the best way to grow agapanthus in cold climates, and they also give some of the best blooms anywhere, because the plants flower most freely when their roots are a little crowded.
- Pot size: choose a container only an inch or two wider than the root mass. A single nursery plant from a 1-gallon pot does well in a 10–12 inch container; a large clump might go in a 16–20 inch pot. Oversized pots lead to lots of leaves and few flowers.
- Material: heavy terracotta, stone or glazed ceramic resists tipping when tall flower stems catch the wind. Agapanthus roots are strong enough to crack thin pots over time, so a pot with a wide opening makes future removal easier.
- Mix: use a quality potting mix with extra grit or perlite (roughly one part grit to four parts mix) for drainage. Do not use garden soil.
- Drainage: a drainage hole is essential. Raise pots on feet in winter so they do not sit in water.
For more on choosing containers and soil for long-lived pot plants, see the flowers and perennials hub.
Watering
Water newly planted agapanthus about once or twice a week for the first growing season, enough to moisten the root zone, then let the top few inches dry before watering again. Established in-ground plants are quite drought tolerant, but for the best blooms give them a deep soak every week or two during dry spells from spring through flowering.
Pots dry faster. In summer, water when the top inch or two is dry, which may be every few days in hot, windy weather. From late fall through winter, cut back sharply: evergreen types in pots need only occasional water to keep the roots from shriveling, and dormant deciduous types need almost none. Wet, cold soil is the most common way to lose agapanthus.
Feeding
Agapanthus is not a heavy feeder, and too much nitrogen produces lush leaves and fewer flowers. In the ground, a spring top-dressing of compost is usually enough. In poor soil or containers, feed from spring until buds show with a balanced or bloom-oriented fertilizer, such as a liquid feed with relatively higher phosphorus and potassium every 2–4 weeks for pots, or one application of a slow-release granular product in spring. Stop feeding after flowering so plants can harden off for winter. Our guide to the best fertilizers for perennials compares options.
Deadheading and Seed
After the flowers fade, cut the stalk down near the base unless you want the seed heads. Removing spent stems tidies the plant and puts energy back into the clump. Some agapanthus self-sow, and in parts of coastal California, as well as in other countries with similar climates, seedlings can spread beyond gardens. Deadheading prevents that. The dried seed heads are also attractive in arrangements if you cut them before they split open.
Winter Care by Zone
- Zones 9–11: evergreen types need nothing beyond removing tattered leaves in late winter. Keep watering light during the cool season.
- Zones 7–8: apply 3–4 inches of loose mulch, such as shredded leaves or pine straw, over the crowns after the first frost. Evergreen foliage may be damaged in hard freezes but usually regrows from the base. Remove mulch gradually in spring.
- Zone 6 and colder: hardy deciduous types can survive in sheltered, well-drained sites with heavy mulch, but losses are common. The safer route is containers. Before hard frost, move pots to an unheated garage, shed or basement that stays roughly 35–50°F. Evergreen types want some light, such as a cool sunroom or a bright garage window; deciduous types can sit dormant in the dark. Water just enough to keep roots from drying completely, then bring pots out after the last frost.
For a wider look at protecting tender plants, see our guide on how to overwinter plants.
Dividing Agapanthus
Divide only when clumps become so congested that flowering declines, the center dies out, or a pot is splitting, typically every 4–6 years or longer. Freshly divided plants often skip a year of bloom while they re-establish, which is why frequent division is counterproductive.
- Divide in early spring as growth starts, or right after flowering in mild climates.
- Dig up the clump or slide it out of the pot. Agapanthus roots are dense; you may need to cut the pot away.
- Use a sharp spade, pruning saw or two garden forks back to back to split it into sections, each with several leaf fans and a healthy chunk of roots.
- Trim damaged roots, replant at the same depth, and water well. Keep divisions evenly moist for the first month.
Why Agapanthus Won’t Bloom
| Cause | Fix |
|---|---|
| Too much shade | Move to a spot with 6+ hours of sun |
| Recently divided or transplanted | Wait a season; avoid disturbing roots |
| Pot too large | Repot into a container just larger than the roots |
| Too much nitrogen | Switch to a bloom-oriented feed or just compost |
| Winter cold damaged buds or crowns | Mulch more heavily or overwinter pots indoors |
| Plant too young | Seed-grown plants can take a few years to flower |
| Drought during bud formation | Water deeply in spring and early summer |
For general bloom troubleshooting across plants, see why won’t my plant bloom.
Pests and Problems
Agapanthus has few serious problems. Snails and slugs chew leaves and hide in the clumps in damp climates; hand-pick at night or use iron phosphate bait. Thrips can streak and distort flowers in warm weather. Mealybugs occasionally colonize leaf bases on potted plants overwintered indoors. In parts of the Southeast and California, the agapanthus gall midge can deform buds so they fail to open; remove and destroy affected buds promptly. Root and crown rot is almost always a drainage problem. Deer and rabbits generally leave agapanthus alone, though no plant is completely browse-proof.
Note that all parts of agapanthus are considered toxic if eaten and the sap can irritate skin, so wear gloves when dividing and keep plants away from pets and children who chew on plants.
Frequently Asked Questions
Is agapanthus a perennial?
Yes. Agapanthus is a long-lived perennial in its hardiness zones, roughly 8–11 for evergreen types and 6 or 7–10 for many deciduous hybrids. In colder areas it can be grown in pots and overwintered indoors.
When does agapanthus bloom?
Most varieties flower from early to late summer, roughly June through August in much of the US, with some reblooming hybrids extending into early fall. Exact timing depends on cultivar and climate.
Does agapanthus spread?
Clumps widen slowly by their rhizomes, and some types self-seed. Deadhead after flowering if you do not want seedlings, especially in mild coastal climates where it can naturalize.
Should I cut back agapanthus in fall?
Cut down spent flower stalks after blooming. Leave evergreen foliage alone except for removing dead leaves. Deciduous types can be cleaned up once their leaves yellow and collapse in fall.
Can agapanthus grow in shade?
It will survive in partial shade but flowers much less. Aim for at least six hours of direct sun, with light afternoon shade only in very hot inland climates.