Description History & Interesting Facts:

Cape Weed is an evergreen flowering plant in the family Verbenaceae, and is native to the area from northern South America, to southern United States, and grows primarily in the subtropical biome, where it occurs in wetlands, wet prairies and near rivers, at altitudes of 0 to 400m. It also quickly establishes itself in disturbed areas with moist soil, around ponds, paddy fields, and ditches.

This little plant became a popular garden ornamental and today it can be found growing in many subtropical and tropical areas of the world, where it has naturalised in many places, including South Africa, where much like cosmos, it is considered naturalised, and is often mistakenly thought to be indigenous. Here, and in many other countries where it has naturalised, it is still grown as an ornamental groundcover in gardens, where, because of its extremely vigorous nature, it is known to invade lawns, and has escaped garden cultivation and occurs as a weed in moist, disturbed areas.

The Invasive Weeds Council of Australia has identified Phyla nodiflora as a serious weed danger and has advised gardeners to only grow it if they are sure they can control it. For this reason I also caution South Africans to be careful where they plant it, and please not to use this plant if you live close to green belts or other wild areas, and especially in moist areas near dams and rivers.

This widely spreading evergreen perennial herb generally grows around 5 to 10cm tall, but mature, unclipped specimens are known to reach greater heights, and the plant can produce stems up to 90cm long, becoming woody at the base as it matures. The green leaves are ovate with serrated margins, and the clusters of small white to pink flowers with their purple bases are showy, and can bloom all summer long. The fruits that follow are capsules that break up into ‘nutlets’ which are small, indehiscent, dry fruits. In its native habitat it is a butterfly food plant and is pollinated by insects, butterflies and moths.

The genus name "Phyla" is Greek for clan or tribe, in reference to how species in this genus often have many flowers that occur in tight clusters. The species epithet "nodiflora" is Latin for a term that means that flowers emerge from nodes. The common name "Matchweed" comes from the fact that the floral stalk and inflorescence together resemble a match.

Uses:

Traditionally the leaves of this plant were fed to cattle.

Medicinally, the leaves and immature stalks are used to make infusions that are administered to children with indigestion or women that have recently delivered a baby. A paste produced from the plant is also applied to boils and ulcers, and it is also used to treat lithiasis, the presence of stones that can originate in any part of the urinary tract. The plant is also used to treat common colds, and freshly pressed juice from the leaves is used on gums to stop bleeding.

In the Garden:

The Cape weed is very tough and because it can take heavy foot-traffic, it’s often grown as a lawn substitute, or planted between pavers and stepping stones. It makes an excellent groundcover that can withstand both drought and flooding, and is often used next to water features. It’s also lovely cascading over pots and hanging baskets.  Because it is easy to grow in waterlogged soils it can be useful in draining sites.

However, care must be taken to restrain its growth, because due to its fast growth rate, it can overtake lawns or gardens. As a lawn substitute or between pavers it will need to be clipped regularly to keep it low and to prevent rampant growth.

Cultivation/Propagation:

Although this plant thrives in the subtropics where it is evergreen, it is fully hardy in cold and frosty regions, where it will die down completely in winter and shoot again in spring. It’s a great coastal plant and can tolerate salt spray, but it does not do well in saline soils.

Cape weed loves to grow in full sun but will also take some shade. Although it loves moist, well drained, sandy or open soils, it is able to grow in poorly drained clay or nutrient poor soils, and once mature, can take short periods of drought.

It tolerates being mown about twice a year, and may be fertilised in spring with a complete fertiliser.

Besides keeping it under control, this plant does not require much attention to thrive - as with many successful weeds, it will grow just about anywhere. 

Problems, Pests & Diseases:

None of note.

Warning:

Phyla nodiflora is not listed as toxic to humans and pets but we always advise parents to supervise small children in the garden and to discourage pets from chewing on plants.