Horticulture Magazine

Agapanthus ‘African Lily’

close up of a purple agapanthus flower

Agapanthus, or ‘African Lily’, is a popular border and container plant, known for its tall stems ending in spherical flower heads in shades of blue and purple, which bloom from mid-summer until early autumn.

The agapanthus plant originates from Southern Africa, and therefore prefers a hot and sunny climate.

Despite this, it is possible to grow it successfully in many UK gardens, providing you choose the right location, and offer it adequate winter protection.

If you’re prepared to put the effort in, you’ll be rewarded with spectacular displays of exotic-looking blue, purple or white flowers, at an eye-catching height.

Some varieties are also evergreen, so will provide attractive green foliage year-round (if not covered for winter).

For anyone thinking about adding agapanthus to their garden, this care and growing guide should provide valuable assistance.

Overview

Official Plant NameAgapanthus
Common Name(s)African Lily
Plant TypePerennial Flower
Native AreaSouth Africa
Hardiness RatingH5
ToxicityToxic
FoliageSometimes evergreen, narrow, strap-shaped leaves
FlowersUmbels of funnel-shaped blue or white flowers
When To SowApril, May
Flowering MonthsJune, July, August, September
Sunlight

Preferred
Full Sun

Exposure
Sheltered

Size

Height
0.5 – 1M

Spread
0.1 – 0.5M

Bloom Time
June – September

Soil

Preferred
Most Soil Types

Moisture
Moist but well drained

pH
Any

Agapanthus Care

When growing agapanthus, it is important to choose a variety to suit your situation.

Providing your garden is sheltered, and you don’t live in too cold an area, you should be able to grow a hardy, deciduous variety in your garden, without moving or covering it during winter.

Fully hardy varieties of agapanthus include A. Midnight blue and A. Blue giant.

flowering agapanthus Midnight Blue
A. Midnight Blue

If you don’t have a sheltered garden, or you wish to grow an evergreen variety, your plant will probably need to be moved into a cool greenhouse or sheltered location over winter.

It is therefore a good idea to grow less hardy varieties of agapanthus in containers in the UK.

Aspect

African Lily plants in the border of an English garden

Agapanthus prefers full sun, so choose a sunny, south-facing spot in your garden in which to plant it or position the container.

Soil & Watering

water being sprayed over Agapanthus plants

Plant in a loam-based compost, and make sure the pot has good drainage, as the plant does not like waterlogged soil.

Water the plant regularly during the growing season of the first year – agapanthus blooms from mid-summer until early autumn, depending on the variety.

Once the plant is established, it should only need watering in the case of a particularly hot or dry summer.

Fertilising

If you’re growing your agapanthus in a garden border, you can feed it a balanced fertiliser once a year in spring, to encourage blooming.

If your plant is in a container, feed it a liquid fertiliser every 2 weeks from April to July.

Planting Agapanthus

Agapanthus plant in a plastic pot that reads 'Midnight Dream 2L Pot'

The best time to plant agapanthus is in spring, around April time.

Try to wait until the last winter frosts have passed – this is especially true for the less hardy, evergreen varieties.

Make sure to cover the roots with at least 5cm of soil upon planting.

If you want to make life easier for yourself, you can also buy potted agapanthus plants in summer, from garden centres or specialist growers.

Keep them well-watered and mulched, to allow the plants to establish themselves.

Habitat & Growing Conditions

a garden path marked out with flowering agapanthus plants either side

Agapanthus’s natural habitat is Southern Africa, where it grows in hot and sunny conditions, with fertile soils.

Many varieties therefore do not cope well in the cold, and need to be sheltered during winter.

Due to its dry natural habitat, agapanthus can tolerate periods of drought – although you should not allow it to dry out completely.

Plant Origins

bumblebee harvests pollen from the lilac flowers of an African Lily plant

Agapanthus is a herbaceous perennial, and part of the Amaryllidaceae family.

There are hundreds of cultivars and hybrids within the genus, ranging from 20cm dwarf varieties to ones that grow to 1.5m tall.

Although it originates from Southern Africa, agapanthus has become naturalised in various other countries, including Britain and Australia.

In some countries, certain varieties are even classified as invasive, for example A. praecox in New Zealand.

Agapanthus plants can be deciduous or evergreen. The deciduous varieties tend to be hardier, whereas the evergreens are more tender.

a butterfly sitting on an agapanthus flower
Agapanthus flowers can help to bring butterflies into your garden

It is recommended to cover evergreens in winter, or grow them in a container, so that you can bring them into a cool greenhouse to protect them from frost.

The flowers of agapanthus plants are most often shades of blue, but can also be lavender, purple or white.

They are trumpet-shaped, and form in large spheres at the ends of tall stems, above the green foliage.

The flower heads will attract birds and butterflies into your garden.

As well as ‘African Lily’, agapanthus is also known as ‘Lily of the Nile’ – all despite the fact that it’s not a lily.

When the plant was first classified, it was incorrectly placed in the Liliaceae family.

Frequently Asked Questions

When do agapanthus flower?
early stages of an agapanthus plant blooming with a garden path in the background

Agapanthus plants have a relatively long flowering period, which stretches from mid-summer until early autumn.

The exact month they begin flowering may be June, July or August, depending on the variety, and the growing conditions.

Are agapanthus hardy plants?
frost covered agapanthus foliage

How hardy your agapanthus plant is will depend on which variety you are growing.

Generally speaking, deciduous varieties of agapanthus are hardier than evergreen varieties.

Once established, there are some deciduous varieties which require very little ongoing care, and can tolerate cold temperatures down to -5°C, or even -10°C.

In contrast, evergreen varieties will need to be mulched, covered or moved inside during winter, to protect them from frosts.

What colours do agapanthus come in?
Agapanthus ‘African Lily’ in blue and white
Agapanthus ‘African Lily’ comes in many colours, including blue, mauve and white

Agapanthus flowers come in all shades of blue, purple and white, ranging from sapphire and indigo to pastel blue, lavender, pink and cream.

The plants have strappy green foliage, and stiff, upright stems.

You can encourage your plants to produce high-quality, colourful blooms by watering well in autumn and spring and feeding with a high potassium fertiliser.

Make sure they have enough access to sunlight and provide them with shelter over winter.

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