Agapanthus

How to grow agapanthus

Discover how to grow beautiful agapanthus, with help from this practical Grow Guide.

A table displaying which months are best to sow, plant and harvest.
Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
Plant
Plant

Do not Plant in January

Do not Plant in February

Do Plant in March

Do Plant in April

Do not Plant in May

Do not Plant in June

Do not Plant in July

Do not Plant in August

Do not Plant in September

Do not Plant in October

Do not Plant in November

Do not Plant in December

Flowers
Flowers

Plant does not flower in January

Plant does not flower in February

Plant does not flower in March

Plant does not flower in April

Plant does not flower in May

Plant does flower in June

Plant does flower in July

Plant does flower in August

Plant does flower in September

Plant does flower in October

Plant does not flower in November

Plant does not flower in December

Cut back
Cut back

Do not Cut back in January

Do not Cut back in February

Do not Cut back in March

Do not Cut back in April

Do not Cut back in May

Do not Cut back in June

Do not Cut back in July

Do not Cut back in August

Do not Cut back in September

Do Cut back in October

Do Cut back in November

Do not Cut back in December

Agapanthus are also commonly known as the African lily. These perennials are native to South Africa, which explains why they thrive in full sun.

Advertisement

Praised for their summer flower heads that are loosely globe shaped in blues, lilacs and whites, they are ideal specimens for containers. Choose between those that offer evergreen strappy foliage or deciduous. The deciduous types are hardier and in a sheltered spot with a mulch applied in autumn they can survive the winter. They’re also able to cope with salty sea winds, making them the perfect plant for a coastal garden.

Discover more about these elegant plants, in our agapanthus grow guide.

Full sun and a well-drained soil are the secrets to success with agapanthus.

Agapanthus with grasses
Agapanthus with grasses

Where to plant agapanthus

Full sun and a well-drained soil are the secrets to success with agapanthus. Plants are able to cope in a coastal situation and are not fazed by sea winds and salty air. Agapanthus are drought-tolerant plants and able to cope in a gravel garden that isn’t watered.

Agapanthus rootball
Agapanthus rootball

How to plant agapanthus

Plant in spring in pots or directly into garden soil. The foot of a south-facing wall should allow the deciduous types to make it through the winter in a mild area.

When planting in containers, agapanthus are encouraged to flower if the root space is fairly restricted. If pots are too big you will get lots of foliage and few flowers. Terracotta pots are ideal as they act as a radiator for the roots in summer. Use John Innes no 2 or 3 as compost and feed plants in spring with a slow release fertiliser.

Dividing agapanthus clump
Dividing agapanthus clump

How to propagate agapanthus

Every four or five years agapanthus grown in the garden or in pots should be divided. Lift the plants and carefully divide the crown, making sure that each section has at least two growing points. You may need to use two garden forks back to back to divide very established clumps. This can be done in spring or after flowering in autumn.

Agapanthus species can be grown from collected seed but the cultivars will not come true to type.

Agapanthus closeup
Agapanthus closeup

Agapanthus: problem solving

Agapanthus a fairly trouble free if they are grown in the right place. The most commonly asked question is ‘Why aren’t my plants flowering?’. This is often due to plants being grown in pots or nutrient-rich compost that offer too much root room. Reduce the size of the container – plants that are very happy don’t see the need to flower.

If you grew your plants from seed they can take up to four years to flower, and it’s not unusual for some plants to take a couple of year to flower after planting.

Agapanthus blooms
Agapanthus blooms

How to look after agapanthus

Water agapanthus in the garden for the first year. Those grown in pots will require watering weekly unless the heavens have opened.

After flowering, leave the faded flower heads on the plant if you want to collect the seed. The attractive seedheads and are often left on over autumn for decorative reasons. On a warm autumn day and before the first frosts, cover the crowns of the hardy deciduous types with straw. If planted at the foot of a south-facing wall, leave the foliage uncut as this provides some winter protection – in this situation you may get away without the mulch. This mulch should be removed in spring.

Tender, evergreen types should be lifted and placed in a cool, light but frost-free place for winter. All potted plants will need some winter protection as if the roots are allowed to freeze plants will suffer. Agapanthus in containers will appreciate an annual feed – tomato feed is ideal just as the plants start to flower.

Agapanthus for cut flowers

Agapanthus offer superb flowers for cutting. Individual blooms command a high price at the florists. However, think before you cut as they aren’t always generous with replacement flowers. 

Agapanthus africanus 'Albus'
Agapanthus africanus ‘Albus’

Agapanthus varieties to try

  • Agapanthus africanus ‘Headbourne Hybrids’ – offering a very full head of lilac-blue flowers in August to October that are held on stems 1m in height. A deciduous type that will overwinter in a sunny, sheltered spot. A popular plant
  • Agapanthus africanus ‘Albus’ – stunning white flowers from August to October. Will overwinter outdoors if in a sunny, sheltered spot. Reaches a height of 70cm
  • Agapanthus inapertus ‘Midnight Cascade’ – dark blue flowers from August to September. Needs a sheltered spot to overwinter outside. Reaches a height of 70cm
Advertisement
  • Agapanthus ‘Jacaranda’ – an early flowering type offering blue flowers in June through to August. Height of 90cm