CARING FOR SPARMANNIA africana
African hemp
Sparrmannia africana is a vigorous evergreen shrub which, if left unchecked and unpruned, can grow 15-20ft tall in the greenhouse or conservatory. It is a native to open woodland in South Africa and Madagascar and, as such, will not tolerate any cold or frost. It is therefore a summer pot grown patio plant at best and must be brought back into a frost free or heated glasshouse in the winter.
African hemp is a member of the lime family and its leaves resemble those of a lime tree but with a covering of soft hairs. This makes the leaves prone to becoming dusty indoors where they are difficult to wipe clean. Another reason for putting the plants outside in the summer.
Sparrmannia can produce the odd cluster of flowers at more or less any time of the year once they are about 3ft tall but, more normally, in late winter or early spring. The flowers appear in large clusters of white flowers at the end of branches. Each flower has a centre of yellow stamens and the flowers are very fragrant. Sparrmannia africana has single white flowers and S. Africana ‘Flore Pleno’ has impressive double white flowers.
These are greedy plants which need a standard liquid fertiliser every fortnight or so in the growing season. They will stand full sun in the greenhouse but will need good ventilation to go with it. Red spider mite and whitefly do find the leaves particularly attractive so, again, it is advised to put the plants outside in summer to reduce the problem.
Clearly this plant is going to get too big for most greenhouses before long. It will need regular potting on to avoid leaf drop at the bottom of the plant and the leaves having a yellowish (or starved) hue. It will also need a regular chopping back in late summer after flowering has finished (combined with repotting) to ensure that it has time to reshoot and flower again in early spring.
Propagation by taking softwood cuttings in early summer is straightforward but we have also found this plant easy to grow from ripe seed sown immediately.
