Agapanthus

How to grow agapanthus

All you need to know about growing beautiful agapanthus, in this practical Grow Guide.

A table displaying which months are best to sow, plant and harvest.
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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, also commonly known as African lily, are perennials native to South Africa. They make an excellent cut flower.

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Loved for their loose globe-shaped summer flower heads in blues, lilacs and whites, they’re ideal specimens for containers. Agapanthus are either evergreen or deciduous. Deciduous agapanthus are hardier than evergreen types, and can survive British winters if grown in a sheltered spot. They’re also able to cope with salty sea winds, making them the perfect choice for a coastal garden.

How to grow agapanthus (African lily)

Grow agapanthus in well-drained soil in a sheltered spot in full sun. Agapanthus do well in pots. Cut back spent flowerheads after blooming and mulch annually with well-rotted compost or other organic matter.

More on growing agapanthus:

Learn more about growing agapanthus in our Grow Guide, below.


Where to grow agapanthus

How to grow agapanthus - agapanthus growing with grasses
How to grow agapanthus – agapanthus growing with grasses

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 tend to flower better if their roots are restricted, so do well in pots.


How to plant agapanthus

Agapanthus rootball
Agapanthus rootball

Plant agapanthus in spring in pots or directly into the garden, ideally at the foot of a south-facing wall or similar, to offer protection in winter.

When planting in pots, choose a terracotta pot, which will keep the roots warm in summer. Use a soil-based compost such as John Innes no 2 or 3, and feed plants in spring with a slow release fertiliser.

Watch Monty Don demonstrate how to plant agapanthus in a pot:


How to care for agapanthus

Water agapanthus planted in the garden for the first year after planting. Those grown in pots will require watering more regularly. Pot-grown agapanthus will benefit from an annual feed – a liquid tomato feed is ideal.

Deadhead spent blooms to encourage more to form, or leave the faded flower heads in place if you want to collect the seed. The attractive seedheads 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 agapanthus with straw, to protect over winter. Leave the foliage uncut as this provides additional winter protection.

Some tender, evergreen agapanthus may survive winter, but it’s best to move them indoors in case of severe winter weather. Lift garden plant and pot them up in a cool, light but frost-free place for winter, and move pot-grow agapanthus under cover, too.


How to propagate agapanthus

How to grow agapanthus - dividing an agapanthus clump
How to grow agapanthus – dividing an agapanthus clump

Divide congested clumps of agapanthus every four or five years. Lift the plants and carefully divide the crown with a sharp spade, 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.


Growing agapanthus: problem solving

How to grow agapanthus - agapanthus closeup
How to grow agapanthus – agapanthus closeup

Agapanthus a fairly trouble free if 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 varieties to try

How to grow agapanthus - Agapanthus africanus 'Albus'
How to grow agapanthus – Agapanthus africanus ‘Albus’
  • 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
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  • Agapanthus ‘Jacaranda’ – an early flowering type offering blue flowers in June through to August. Height of 90cm