Pennisetum, a genus with about 80 species which originate from warm-temperate to tropical regions of Australia, Asia, Africa and Europe has been put to many uses in agriculture as well as civil, commercial and domestic landscaping.

Many would be familiar with P. clandestinum more commonly known as Kikuyu Grass. This rampant, tough grass is a great pasture grass and is also popular in public areas with high pedestrian and vehicle traffic. Unlike most Pennisetum it has vigorous rhizomes which can run deep in the soil and horizontally. These cause problems when grown adjacent to garden beds, requiring a committed maintenance programme to control. As a lawn it is hardy and quick to recover if it does get damaged.

As ornamental grasses the most popular are P. setaceum (African Fountain Grass) and P. villosum (Feather Top) – both introduced from Africa – and P alopecuroides (Swamp Foxtail) which is native to Australia from southern NSW to northern QLD. P. setaceum comes in a magnificent burgundy colour. Cultivars available are ‘Rubrum’ which grows to a height of about 1 metre and displays a soft weeping habit, and ‘Burgundy Giant’, a more erect grass to 2 metres high with rich glossy red blades.

The native Pennisetum is often used in revegetation projects and due to its hardiness is a popular roadside plant. A great deal of work has been done to develop cultivars of this plant resulting in a variety of colours and sizes in seed heads and a choice in plant heights and preferred growing conditions. Certainly it is a must for any gardener working on a grassland or low scrub style garden.

Most Pennisetum grasses require only a simple maintenance programme once established. Fertilize when first planting out and only subsequently if your soil is poor. Fertilizers high in available nitrogen will result in massive leaf growth at the cost of less flower heads. Prune the clump back close to ground level once a year to keep it looking fresh. Split the clump, replanting about one quarter, every 3-4 years. As propagation by rhizome is most effective, this would be a good time to gain a few extra plants. Heavy frosts are probably the only real threat to the plant with some varieties being more sensitive than others. Usually the plant will spring back once the frosts are over.

Both of the introduced species I have mentioned have shown themselves to have weed potential. Responsible gardening practices should be observed if you have these plants in your garden or are considering planting them. Remove and burn, bury or compost the seed heads before they dry out and naturally scatter and in no circumstances should you dump unwanted garden waste in the bush or along the roadside.