The ideal spacing for agapanthus depends on the variety's size, generally ranging from 12 to 24 inches (30 to 60 cm) apart.
Plant 60cm apart for tall varieties, and 30cm for dwarf varieties with the plant crown at soil level. When planting in pots, root congestion is not a major concern, as Agapanthus plants tend to respond quite well to this. When the roots have too much space, leaf growth will be encouraged rather than flower production.
- Plant in groups for a fuller display, usually in groups of 3, somewhere that gets plenty of sunlight. - Ensure the crown is just below the soil unless the plant has some leaves, in which case leave them exposed with the rest of the root system under the soil. - Water well once planted.
Urban areas: Agapanthus invades gardens and can spread vegetatively over many years, also slowly spreading along roadsides.
Do not plant agapanthus in shady spots or areas with poor drainage, as they need full sun and well-drained soil to flower well and avoid root rot; also avoid planting near bushland or sensitive ecosystems due to their invasive potential, opting for sterile varieties or containers if concerned about spread.
Whether you're planting into a pot or directly into the ground, herbs like oregano, thyme, prostrate varieties of rosemary and other herbs are perfect companions for your agapanthus. Sassy™ Thymus serpyllum 'WT03' is a variety of thyme that's both ornamental and edible.
Bulb rot and root rot are both agapanthus problems that start underground. They show themselves above ground in yellow, wilted leaves and sometimes stunted plants. If you dig the plants up, you'll find the roots or bulb decayed and discolored. If one of your plants is infected with root or bulb rot, it can't be saved.
It is a perennial plant that can live for up to 75 years. Its evergreen leaves are 2 cm wide and 50 cm long. Its inflorescence is an umbel. The flowers are blue, purple or white and bloom from late spring to summer, followed by capsules filled with black seeds.
Most authorities confirm that agapanthus is very difficult to get rid of, even with powerful sprays. Common recommendations are for glyphosate, metsulfuron-methyl (MSF600) and triclopyr (Triclo). Our experience is that they all will work, but that glyphosate and MSF600 are more effective at some times than at others.
Agapanthus do well in both pots and the ground, with the best choice depending on your goals: pots offer control for limited space, frost protection (by moving indoors), and preventing spread, while the ground allows them to naturalize and form large clumps for a bigger impact, though they need more effort to manage if they become invasive. Pots are great for patios, balconies, and colder climates, while in-ground planting suits sunny garden beds.
Agapanthus planting is best performed in the fall or winter in warm climates, and in the spring after the danger of frost has passed in cool climates. The ravishing, spherical flower clusters will arrive in early to mid-summer.
Feed your agapanthus with a high-potassium feed (like tomato feed) fortnightly during the growing season. Deadhead spent flowers and mulch around the base of the plant in autumn to help give some protection from the cold. Carry out any lifting and dividing in early spring, before the flowering season starts.
Are Agapanthus Drought Tolerant? Agapanthus are hardy plants, that will tolerate dry conditions. Plants will be healthier when kept moist but can survive dry conditions.
The best time to plant your agapanthus from bare root is from March to May. If planting agapanthus in pots, use a mixture of soil and compost mixed with a little sand and grit to help drainage. Agapanthuses like a well drained soil/compost.
— Plant the roots so that the crown is around 5cm deep. If your Agapanthus already have leaves or shoots, plant the roots with the leaves exposed above the soil surface.
Agapanthus plants thrive in well-drained soils, preferring full sun but also tolerating partial shade. Their resilience against drought, once established, further enhances their appeal.
"A pretty garden plant but ecologically dangerous — agapanthus has dense clumping roots that help it displace native plants and prevent their regeneration," she warned. When spotted, it's "best to dig it out as it can be resistant to herbicides", Booth said. "It retards fire and has the potential to alter ecosystems."
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.
It's generally not illegal to plant Agapanthus in most places, but it's highly discouraged in many regions (especially Australia, parts of the UK/Europe, and California) because it's considered an aggressive, invasive weed that spreads into natural areas, impacting native plants. Laws vary by location, but you'll often find local council bans or strong recommendations not to plant common varieties, encouraging sterile cultivars instead to prevent seed spread into bushland and waterways.
A problem with flowering is usually due to one of the following issues:
Annuals To Plant With Agapanthus
Both large and small-leaved types of dusty miller, alyssum, calibrachoa, and sun-loving New Guinea impatiens grow large enough to stand up to the large Agapanthus leaves and will add a contrasting layer of color and texture.
There are both evergreen and deciduous species. The Genus name is derived from Ancient Greek ἀγάπη (agápē) 'love' and ἄνθος (ánthos) 'flower'. Plant in full sun to partial shade in sandy-loam well-drained soils. The rhizomes should be planted 1 inch deep and 8 inches apart.
Agapanthus prefer full sun but in hot climates do better in partial shade . They attract butterflies, birds & 🐝's and are deer and rabbit resistant . They prefer fertile , moist and well drained soil, ideal for boarders they also can be grown in pots , but would need dividing more regularly .
Too much shade, cold weather and lack of winter protection are also common reasons for agapanthus to fail to flower. Too much winter warmth may lead to early flowering, but the flower quality will be poor. If you are a member of the RHS, you can use our online Gardening Advice service.