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Alluring Agapanthus

Easy-to-grow Agapanthus produce glorious clusters of lily-like blooms that last throughout the summer.

Easy-to-grow Agapanthus produce glorious clusters of lily-like blooms that last throughout the summer.

The six or so species that comprise the genus Agapanthus (African Lily) are found growing wild along the coastal belt and inland mountainous regions of southern Africa. These clump forming perennials have been collected from their natural habitats and developed into many spectacular garden hybrids that adorn landscapes all around the world.

The genus Agapanthus was established by L’Heritier in 1788. It used to be included in the Liliaceae (lily family), was then moved to the Amaryllidaceae (amaryllis and daffodil family), moved again into the Alliaceae (onion family) then back to Amaryllidaceae and now resides in its own family, the Agapanthaceae. All this taxonomic to-and-fro’ing seems to be about whether its umbellate inflorescence is considered to be of greater taxonomic importance than its superior ovary. It is placed in its own family, a sister family to the Amaryllidaceae, on the strength of its superior ovary, the presence of saponins and the absence of amaryllid alkaloids. The Agapanthaceae consists of only one genus that is endemic to southern Africa.

Agapanthus, commonly called the African Lily in the Northern hemisphere (Blue Lily in England), produce glorious clusters of lily-like blooms that last throughout the summer. These clusters, made up of lots of bell-shaped flowers, can be globe-shaped or pendular, held aloft on vertical stems that can reach 1.2m tall. They mainly come in shades of blue, from a dusky, powder blue to an almost indigo-purple, but you can get some superb white varieties as well. They are at their best in mid- to late summer, even stretching into the autumn, thus adding swathes of blue or white flowers to the garden long after the spring madness has calmed down.

Some Agapanthus are deciduous, dying back completely in winter, whilst others are evergreen, retaining their strap shaped leaves all year round. Some are large growing with leaves almost a metre long. Others are dwarf with leaves 15 to 20cm long and flower spikes less than 30cm in height. They last well in water and are often used in flower arrangements.

The fleshy roots are tough and enduring and help to retain steep banks in gardens and prevent damage from water erosion. In fact, Agapanthus hybrids and cultivars are so versatile that they can be used effectively regardless of whether you are looking for a pot plant specimen or a ground cover for a vast commercial landscape.

The fountains of simple strap-shaped leaves produced by Agapanthus provide a wonderful contrast with other types of foliage even before the flowers open. Leave the hardier varieties alone in a sunny, sheltered spot in the garden and they will form bold clumps that will flower reliably year after year. They are equally suited to growing in pots on the terrace or patio, where not only will they look sensational, but also you can move them around for best effect. All make excellent, long-lived cut flowers. The decorative seed heads can be left to add interest to the border in autumn and winter and, as they dry, will scatter their seed. The seed heads also can be cut and dried for indoor decoration.

Wind, birds and insects pollinate agapanthus flowers. Seed is dispersed by the wind. Although the seed is usually prolifically produced, it may be heavily parasitized by a host of insects. Despite this the percentage of seed germination is usually high.

WHICH VARIETY TO PLANT

In South Africa and other temperate areas

Evergreen winter rainfall or all year rainfall species

• Cape agapanthus (A. africanus subsp. africanus) has spreading, deep blue open flowers on rounded umbels reaching 30cm across. This species is endemic to the fynbos region of the Western Cape. It does not grow well elsewhere.

• Fynbos agapanthus (A. africanus subsp. walshii) has longer semi‑tubular drooping flowers and shorter leaves. Also suited to the fynbos garden, it occurs naturally in the Grabouw district.

• Eastern Cape agapanthus (A. praecox) is the most popular and widespread species, ranging from the Western Cape to KwaZulu‑Natal with many local forms and cultivars. Its leaves reach 60cm and its umbels are borne on flower stalks 80 to 100cm tall. The blue (or rarely white) flowers are more than 5cm long. A. proecox subsp. orientalis is the most popular. ‘Mt Thomas’ has deep blue flowers.

• Knysna agapanthus (A. praecox subsp. minimus syn. A. comptonii) is smaller and lacking in the dense growth of the former. Its inflorescence may grow up to 60cm tall and the pale flowers reach 4,5cm long. It is confined to the eastern margin of the Western Cape and southern coastal region of the Eastern Cape. Recommended cultivars are ‘Adelaide’ and ‘Storms River’.

Winter deciduous, mainly summer rainfall species

• Highveld agapanthus (A. campanulatus) has 50cm tall, slightly grey‑green leaves. The umbels reach 20cm in diameter on stalks 70cm tall with pale to deep blue spreading flowers. It naturally occurs in grassland in the Drakensberg (KwaZulu‑Natal) and eastern Free State to near Johannesburg (Gauteng) in the north. Recommended cultivars include ‘Hardingsdale’ and ‘Albovitatus’ — the latter has white striped leaves.

• Drakensberg agapanthus (A. caulescens syn. A. nutans) has 60cm tall, glossy bright‑green leaves in clusters. The umbels reach 20cm in diameter, on stalks 60‑130cm tall with deep blue spreading flowers. It flowers from January to February and naturally occurs in grassland from the Drakensberg (KwaZulu‑Natal) and northwards to Mpumalanga (Drakensberg) and the Waterberg (Limpopo Province). A recommended cultivar is ‘Politique’,

• Kransberg agapanthus (A. coddii) has 45cm long leaves and umbels on stalks reaching 100cm. The deep blue spreading flowers con be 4cm long. It is restricted to south‑facing cliffs of the Krantzberg (Limpopo Province).

• Mpumalanga agapanthus (A. inapertus subsp. inapertus) has umbels on 180cm stalks with deep blue to violet (rarely white) spreading flowers. It occurs among grassland along the northern Drakensberg of Mpumalanga and Limpopo Province. The cultivar ‘White’ has white flowers.

• Graskop agapanthus (A. inapertus subsp. pendulus) differs by its smaller heads of drooping flowers. This beautiful and popular plant occurs in the Sabie/Graskop district of Mpumalanga. Recommended cultivars are ‘Wolkberg’, ‘Lydenburg’ and ‘Sky’. ‘Graskop’ has very dark violet‑blue flowers.

Popular cultivars or garden hybrids on the local market include Agapanthus praecox subsp. orientalis ‘Blue Velvet’, one of the most astounding dark blue flowering Agapanthus to be found; it is tall growing with huge flower heads of deep cornflower blue. Agapanthus ‘White Ice’ is a stocky, low‑growing selection with large flowers on very short, sturdy stems. A. praecox subsp. orientalis ‘Silver Star’ has variegated leaves and pale blue flowers. A. africanus ‘Double Diamond’ is very new on the local market and produces double white flowers on short stems. The list is endless, with a continuous stream of new Agapanthus making an appearance on the local garden scene. Whatever their name and claim to fame we can embrace them all and say they are proudly South African and worthy of a place in our hearts.

In the Northern Hemisphere

The first Agapanthus to arrive in England, from their native South Africa, were too tender to be grown outdoors. Fortunately, the Hon. Lewis Palmer, who fell in love with their impressive flowers, set about breeding new varieties that would be better suited to the English climate. Consequently there are now several hardier varieties that will withstand the winter weather. The main difference between the two types is that the tender (A. africanus) which originated from the milder coastal areas are evergreen while the hardier (A. campanulatus) coming from moister, mountain grassland, have slightly smaller flowers and die down in winter before re-emerging again the following spring. You can still obtain the more tender types, but you will need to protect these in winter by keeping them in a cool greenhouse or conservatory.

Smaller varieties are ideal for the front of the border, where you will get the full benefit of both the flowers and foliage. ‘Lilliput’, as the name suggests is one of the smallest hardy varieties at 45cm, with rounded umbels of deep blue flowers, and ‘Royal Blue’ (60cm) has dramatic dark blue flowers, which are set off to perfection by their bright green leaves. For soft blue flowers choose either ‘Pinocchio’ (60cm), which will eventually form a dense clump, or ‘Peter Pan’ (40cm), the flowers of which are so pale they are almost a grey-blue. ‘Glen Avon’(50cm), on the other hand, offers huge globes of trumpet-shaped, bright blue flowers with dark stripes on each petal. While the new ‘Back in Black’ (65cm) and ‘Black Pantha’(40cm) are very much on the inky, blue-black end of the colour spectrum.

For the middle of the border you should select one of the ‘Headbourne Hybrids’ (80cm), named after the garden where they were first raised by the Hon. Lewis Palmer. They come in a wide range of blue – and yes even white – flowers which are gently pendulous. Another wise choice is the ‘Bressingham Hybrid’ (75cm) which is worth growing for its tough, robust growth and deep blue flowers.

For the back of the border ‘Blue Giant’ is one of the tallest coming in at an impressive 1.2m. The flowers are pure opulence! They are open trumpets forming a large globe, which is supported on a sturdy spike. Agapanthus inapertus subsp. Intermedius is taller still at 1.5m with impressive blooms that form large, pendulous cluster of mid-blue bells. ‘Blue Globe’ is slightly shorter at 1m, but what it lacks in height it makes up for with its even bigger flowers. Finally, A. campanulatus is a vigorous plant, reaching 1m, which produces soft blue flowers held above narrow grey-green leaves.

GROWING

Agapanthus is easy to grow and it does well even in the poorest of soils, but it must receive some water in summer. To perform at its best, give it rich, well-drained soil with ample compost (decayed organic matter) and plenty of water in spring and summer. As with most plants they benefit most from regular (weekly) deep drenching as opposed to frequent superficial waterings. It prefers full sun, and some cultivars will flower in semi-shade.

All the evergreen Agapanthus are best lifted and divided every four years or so to ensure flowering.

In northern countries with cold climates the tender varieties will need moving to a frost-free conservatory or greenhouse before the weather turns cold, where they will need to be over-wintered The hardier types can be left outside all year with just a generous mulch of chipped bark for protection.

PROPAGATION

Once you have developed a love for these wonderful plants you are going to want a lot more! Propagation is by seed or division. Because agapanthus plants hybridize freely with each other, and are all in flower at the same time, you can be sure that there will be hybrids from seed harvested in gardens where a variety of species are grown. To get pure seed of any Agapanthus species it would have to be habitat collected or pollinated under strictly controlled conditions. Even then, there is always a degree of variation in the offspring. If you are after a particular cultivar, division is still the most reliable way of making sure that the material being propagated will be exactly true to type.

Seed can be sown fresh, in late summer to early autumn, but in cold climates it can be kept refrigerated (not frozen) and sown in spring. It must be kept in the refrigerator or it will perish. Seed should be sown in deep (10 cm) trays, in a mixture of equal parts river sand and fine compost, and kept semi-shaded and moist. Seed germinates readily within six to eight weeks. The seed should be sown thinly as the seedlings will stay in the tray for their first year. Seedlings should be potted up into individual containers during their second year and can be planted into the garden or permanent pots in their third year. Flowering can be expected from their third or fourth year.

Clumps are best lifted and divided just after the end of their flowering period in late summer to early autumn. Unlike the deciduous species, which should be left alone for up to 6 years and often don’t flower the first year after being divided, the evergreens are best lifted every four years and usually flower best in their first season after dividing. You need your health and strength to lift and divide large agapanthus clumps — what works well is to place two garden forks back to back in the centre of the clump and prise them apart. Or the clump can be chopped up with a spade. Reduce the length of the foliage by one half and reduce the roots by two-thirds. Replant immediately and water thoroughly.

PESTS AND DISEASES

Agapanthus is generally pest- and disease-free. Foliage may be attacked by red spider mites, thrips, and mealy bug but need only be sprayed if infestation is severe. Agapanthus are famous for harbouring snails, although the snails do not seem to cause any damage to the plants themselves. The best way to combat them is to remove them by hand or to keep ducks. Botrytis, visible as brownish lesions, may attack the flowers preventing them from opening. There is no cure, it can only be prevented by spraying before and after the buds break open. The foliage may be attacked by the fungus Macrophoma agapanthii causing die-back of the leaves, and in severe cases can be combatted with a fungicide like mancozeb or captab as a full cover spray.

CONTAINER GARDENING

Agapanthus in containers should be potted up using a loam-based compost, and planted with their crowns approximately 5cm below the surface of the compost. Water them freely when they are actively growing, but less so in winter when they are dormant. Apply a balanced liquid fertiliser from the beginning of spring until they start to flower. If you can, resist the urge to cut back the dying foliage until it has gone quite crispy, so that most of the goodness goes back into the rhizome to produce a good flowering display the following year.