'Sky' and 'Lydenburg' are two of the most floriferous and attractive forms of agapanthus to grace the summer garden. Both were thought to be forms of Agapanthus inapertus subsp. hollandii, but recent studies show that 'Lydenburg' may be a hybrid. Like all other forms of A. inapertus they are deciduous and prefer full sun.

Description
Agapanthus inapertus subsp. hollandii has six to eight strap-shaped leaves per plant, produced on a distinct stem. The plants are deciduous with the leaves disappearing entirely in winter. The tuberous rhizomes gradually spread, forming substantial clumps. The flower stalks are held erect at the bud stage and become droopy as the flowers open. The flowers are tubular and this subspecies has distinctly flared, narrower perianth segments which are shorter than the length of the perianth tube.

The form 'Sky` has pale, sky-blue flowerheads borne on erect, tall stalks. Flowers occur from January to March and follow after those of the evergreen species, A. praecox in the garden.. The attractive greyish upright leaves, coupled with the elegant bearing of the inflorescence, make this a very suitable plant for the border. Although it prefers full sun, it will also flourish where it receives late afternoon shade, and the pale flowers are particularly attractive in the gentle light.

'Sky' was originally collected in the Lydenburg district and has grown at Kirstenbosch for many years (Graham Duncan pers.comm.).

Agapanthus 'Lydenburg' has strikingly beautiful, deep blue flowers which are long lasting and make this one of the most attractive of all the deciduous agapanthus forms cultivated at Kirstenbosch. New research (Zonneveld & Duncan 2003) suggests that it is not a form of A.inapertus subsp hollandii, but a hybrid between this subspecies and another of the A.inapertus subspecies. The flowers are complemented by fresh green leaves, which like those of 'Sky', are neat and not too large.

Distribution
Apapanthus inapertus subsp. hollandii occurs in Mpumalanga. This is the summer rainfall region of South Africa and plants are found growing naturally in the Lydenburg , Graskop and Pilgrim's Rest areas, on well-drained soils in open grassland. These areas are at fairly high altitudes and receive plentiful summer rain. Summers are hot; 28-30°C and winters cold and frosty. Both 'Lydenburg' and 'Sky' respond well to cultivation and do not rot in winter rainfall regions, provided they have good drainage.

Name
Agapanthus inapertus is one of ten (new research suggests this might be reduced to six) species of Agapanthus found in South Africa. They include the well known A. praecox, A. caulescens, A. coddii, A. africanus and A. campanulatus. A. inapertus is one of the lesser known species, yet its five subspecies include some most attractive garden plants, including the inky blue A. inapertus subsp. pendulus 'Graskop'.

The subspecies hollandii was first discovered in 1929 by F. H. Holland, hence the specific name.

Ecology
The pendulous species of agapanthus are pollinated by sunbirds as well as insects. The seed once released is wind dispersed.

Uses and cultural aspects
The local people boil parts of agapanthus and add it to bathwater to improve a person's luck.

Growing Agapanthus 'Sky' and 'Lydenburg'

Both `Sky` and 'Lydenburg' are well suited to mass display or smaller groups in a mixed border. They are also ideal as container subjects . Being deciduous they can be interplanted with such plants as Chasmanthe floribunda var. `duckittii`which is winter growing and dormant in the summer. Lobelia anceps, treated as an annual, flowers in summer, producing light blue flowers and is ideal in a mixed border with Agapanthus `Sky`.

Both these agapanthus require a well-drained, fertile soil . They need to be cut back at the end of the growing season, removing all of the dried leaves and flower spikes. A generous layer of mature compost can be scattered over the surface of the dormant agapanthus. Agapanthus are water wise and do not require excessive watering. Once a week is quite adequate. Approximately every eight years, Agapanthus `Sky` and 'Lydenburg' need to be lifted after flowering and each clump divided Each division should have at least two growing points. For propagation purposes one growing point is sufficient. Dividing stimulates flowering and within two growing seasons the plants will be back to their best, producing an abundance of flowers.

The other method of propagation is from seed. Unfortunately agapanthus plants cross pollinate readily and consequently one is never sure of what the seed will produce. Seed needs to be sown soon after it is collected, or stored in the fridge (not freezer) until spring. Seed should be sown in deep trays in semi-shade and kept moist. Fresh seed should germinate in 6-8 weeks. Seedlings should be thinned, but not transplanted from their seed trays until the following year. Plants grown from seed will take about four years to flower.

Generally agapanthus are not bothered with pests, but the leaves and flower buds can be affected by red spider mite, mealybugs, thrips and gall midge fly. Apply a full cover spray with a contact insecticide as soon as pests are observed and repeat every two weeks until the infestation has been eliminated.

References

• Duncan, G.D. 1998. Grow agapanthus. Kirstenbosch Gardening Series. National Botanical Institute, Cape Town.
• Leighton, F.M. 1965. The genus Agapanthus L'Héritier. Journal of South African Botany, Suppl. vol. 4.
• Zonneveld, B.J.M. & Duncan, G.D. 2003. Taxonomic implications of genome size and pollen colour and vitality for species of Agapanthus L'Héritier (Agapanthaceae). Plant Systematics & Evolution 2141:1 15-123.