Agapanthus

A South African perennial producing globe-shaped clusters of blue or white trumpet flowers on tall, naked stems. Agapanthus thrives in containers where root restriction actually promotes more prolific flowering. In cold climates, grow in pots and overwinter in a frost-free location or choose the hardier deciduous varieties.

Agapanthus can be grown from seed, though plants take 2-4 years to reach flowering size. Sow fresh seed in spring in moist, well-drained seed compost at 15-20°C. Germination takes 3-6 weeks. Seedlings vary in flower color, which can be an exciting lottery. For named varieties, division is the only option—lift congested clumps in spring, wash roots, and divide into sections with at least 4-5 growth points each. Replant immediately and water well. Newly divided plants may take a year to settle before flowering freely.

The Season Plate

Your Agapanthus Year

Composed for Zone 7 · typical seasons · frost passes Apr 2, returns Nov 1

Sow Agapanthus Mar – Apr, Sep, pick Jun – Aug. Set your climate below and every date on this plate re-times itself.

Sowing window

Mar – Apr, Sep

re-timed to your frost dates

Plant out

after Apr 2

once frost risk has passed

First picking

around Mar 15

≈ 365 days from sowing · 3-4 years per plant

Composed for —ColdTemperateMildWarmUse my locationUsed once to set your season · only the zone is kept

Week-by-week Agapanthus reminders watering, feeding and pruning, timed to your dates

In the app

Frost alerts for your garden a warning before a cold night costs you the crop

In the app

Succession sowing dates so the picking never gaps mid-season

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Prefer email? Get monthly reminders in the Almanac

Keep my dates — free for 7 daysWe nudge you as each window opens · cancel anytime

Agapanthus, commonly known as Lily of the Nile or African lily, produces spectacular globes of trumpet-shaped flowers on tall, leafless stems above strap-shaped evergreen or deciduous foliage. Native to South Africa, these plants thrive in warm, sunny positions and are among the most rewarding summer-flowering perennials for mild climates and container culture.

Plant in full sun in well-drained, moderately fertile soil. Agapanthus performs remarkably well in containers, where root restriction actually promotes more prolific flowering—a pot-bound agapanthus will bloom far more freely than one planted in an open bed. For container growing, choose a pot only slightly larger than the root mass and do not be in a hurry to repot. Feed regularly with a high-potassium liquid fertilizer during the growing season to fuel flower production.

In cold climates (below Zone 7), grow agapanthus exclusively in containers that can be moved to a frost-free greenhouse or cool conservatory for winter. The deciduous varieties (Headbourne Hybrids and similar) are hardier than the evergreen types and can survive outdoors to Zone 7 with heavy winter mulching. In mild areas, agapanthus makes a spectacular permanent border planting, particularly effective in coastal gardens where salt tolerance is needed.

Agapanthus creates stunning combinations in borders and containers. The blue globes pair magnificently with orange crocosmia, yellow daylilies, and pink roses. In Mediterranean-style gardens, combine with lavender, salvia, and ornamental grasses. White agapanthus glows in evening gardens alongside silver-leaved plants. For containers, surround a large agapanthus pot with smaller pots of trailing lobelia, geraniums, and silver helichrysum. In coastal gardens, agapanthus thrives alongside oleander, rosemary, and seaside daisies.

The Society Table

Daylily belongs beside it.

Old growers' knowledge, checked against Agapanthus's real companion table below — test any plant you're growing.

Grows well in the company of · 3

DaylilyPerennial SalviaLavender

Keep apart · 0

no recorded foes

Plant Agapanthus with good neighboursThe planner flags conflicts before they're in the ground

Agapanthus performs well in moderately fertile, well-drained soil with a pH of 6.0-7.5. Good drainage is essential, especially for winter survival in borderline climates. Amend heavy clay with grit and organic matter. For container culture, use a quality loam-based potting mix. Feed fortnightly during the growing season with a high-potassium liquid fertilizer (tomato feed works well) to promote flowering. Reduce feeding in late summer and stop entirely in autumn. Top-dress in-ground plants with compost in spring.

Ideal Temperature

Hardiness Zone Compatibility

Agapanthus makes superb cut flowers. Cut stems when the first florets in the globe have opened and others are showing color. Cut in the morning and place immediately in deep water. The flower globes last 7-14 days in a vase, with individual florets opening in succession. The round green seed heads are also attractive in arrangements and dry well. For seed collection, leave a few heads on the plant until the capsules split open to reveal black seeds.

Storage & Preservation

Agapanthus seed heads dry beautifully for arrangements. Cut stems when seeds are mature but before capsules fully open, and stand upright in a dry vase to air-dry. The architectural globes maintain their shape for months. Seeds can be collected and stored dry for spring sowing. For bulb storage in cold climates, lift container plants before frost, cut back foliage by half, and store in a cool (5-10°C), frost-free, dimly lit location. Water sparingly during winter dormancy—just enough to prevent roots from drying out completely.

Troubleshooting Common Problems

The most common complaint is failure to flower, which is usually caused by insufficient sun, over-potting (root restriction promotes bloom), or excessive nitrogen fertilizer. Switch to a high-potassium feed and keep plants slightly pot-bound. Frost damage is the main threat in cold climates—deciduous varieties are much hardier than evergreen ones. Slugs can damage emerging flower stems in spring. In mild, wet winters, crown rot can be fatal; ensure drainage is excellent and consider covering with a cloche in persistently wet regions.

Growing Tips

1. Plant Agapanthus in full sun for the best flowering. Plants grown in partial shade will produce fewer flower stalks and the stems may lean toward the light, resulting in a less attractive display.
2. Agapanthus blooms best when slightly root-bound, so avoid overpotting container-grown plants. Choose a pot only one size larger when repotting, and allow the roots to fill the container before dividing.
3. Improve drainage in heavy clay soils by adding generous amounts of grit, perlite, or coarse sand before planting. Agapanthus rhizomes are highly susceptible to rot in waterlogged conditions, especially during winter dormancy.
4. Feed with a high-potassium fertilizer such as tomato feed from late spring through midsummer to encourage strong flower production. Avoid high-nitrogen feeds, which promote lush foliage growth at the expense of blooms.
5. Deadhead spent flower stalks by cutting them at the base promptly after flowering. This prevents the plant from expending energy on seed production and redirects resources into building the rhizome for next season's blooms.
6. Protect plants in USDA zones 7 and colder by applying a thick layer of mulch (15-20 cm) over the crown after the foliage has died back in autumn. Remove the mulch gradually in spring as new growth emerges to prevent the shoots from etiolating.
7. Water deeply but infrequently during the growing season, aiming for one thorough soaking per week rather than frequent light watering. This encourages deep root development and builds drought resilience in established plants.
8. Divide overcrowded clumps in spring when new growth is just starting. Use a sharp spade to split the clump, ensuring each division has at least three to four growing points and a good mass of roots. Replant immediately and water well.
9. When growing Agapanthus in containers, use a loam-based compost such as John Innes No. 3 mixed with additional grit for drainage. Avoid peat-based composts that can become waterlogged in winter and overly dry in summer.
10. In regions prone to late spring frosts, delay removing winter protection until all risk of hard frost has passed. Emerging shoots and young flower buds are more vulnerable to frost damage than mature foliage.