Spear Flower/Ardisia Japonica ‘Marginata’
The common name of this evergreen plant appears to arise from the shape of the anthers, which are spear-pointed. This Ardisia is one of the less-common species grown as houseplants and is altogether a much more, compact plant. The pretty leaf variegation of this cultivar is some compensation for the small and rather intermittent white flowers, which are nicely scented. The small red fruits which follow are often long-lasting and add extra interest. From Japan and China, Ardisia japonica has glossy, serrated-edged leaves which often develop bacterial nodules along the leaf margins: these should be left in place and not picked off. For the best effect, the foliage of the Spear Flower should be kept clean and sponged regularly with clean water.
Provide the Spear Flower with a minimum Winter temperature of 12°C (54°F); in Summer, prevent very hot conditions from stressing this plant by keeping the growing environment well-ventilated. This is particularly important when the plant is in flower.
Full sun to half shade is preferred, although Ardisia japonica ‘Marginata’ should be screened from bright light in Summer.
Aim to keep themoist throughout the growing season: water thoroughly with tepid water and then water again once the very top of the compost begins to dry out. In Winter, only water when top 1cm (l/2in) of the compost is dry.
This plant likes a daily misting at all times, except when in flower and when temperatures fall below 15°C (60°F).
Feed Ardisia japonica ‘Marginata’ every fortnight during the growing period: use a general-purpose plant food.
Pot-on this plant in late Spring, using a good-quality compost: leggy plants should be pruned hard to 10cm (4in) in February, repotted and grown on. If the plant bleeds profusely, allow the cuts to heal before repotting. Thin out any weak or crossing growths.
Hand pollination, with the aid of a tiny brush, may help the fruit to set. This is not a long-lasting genus: after 2-3 years, if the plant’s growth is poor – even after subjecting it to harsh pruning – the plant should be discarded.
Scale and Mealy Bugs will cause the plant to deteriorate: eradicate these sap-sucking pests by using a systemic insecticide or by dissolving them with methylated spirit applied with a cotton bud.
Cultural problems include fruit-drop as a result of excessively high temperatures, and fruit shrivelling from lack of humidity.