Plant of the month – Pennisetum orientale
Some plants call out to be touched and fluffy pennisetum grasses are certainly one of the most tactile. There is something quite special about Fountain grasses with their fluffy often almost caterpillar like cylindrical rounded heads of flower, that are so enthusiastically produced over the summer months. They are known as fountain or foxtail grasses, for their graceful arching form and brush-like inflorescences. Pennisetums are among the most eye-catching of the ornamental grasses that have become fashionable in recent years.
Pennisetums are quite a large family but coming from much warmer parts of the world than the UK and because of this we can grow a small proportion here, as most are considered generally too tender for our climate. They can be a little fussy and many may have tried a variety or two only to lose them after their first winter. Pennisetums love, without exception, full sun and reasonably well drained soils. While Pennisetums will grow in any average garden soil, they are very intolerant of winter wet, so if you have sunny open places, and it doesn’t tend to matter how dry, then the fountain grasses are likely to be happy.
Low growing, compact and incredibly floriferous, Pennisetum orientale is a clump forming perennial grass and one of the most striking hardy “oriental fountain grasses”. Blooming over an exceptionally long season, its fluffy spikes rise high above the foliage, gracefully arching upward or outward, and cascading down the deep grey green foliage. Resembling bottle brushes, the flower spikes consist of soft, pinkish spikelets that are formed in long, narrow panicles, about 4.5 inches long. They sway in the breeze and literally glow when lit from behind in the early morning or layer afternoon sun. Over time the pink panicles mature to a light brown and the foliage turns straw coloured which all continues to keep the plant looking great well into the winter.
It is a versatile plant than can be used as a specimen or in groups en masse. Due to its size, I often use it at the front of the border where it can provide texture, colour and contrast. It is also great used as a cut flower too. It has also been give the RHS prestigious AGM award. Their habit of sulking until early May makes them ideal for under-planting with spring bulbs – the emerging leaves will hide the dying foliage of daffodils and species tulips.
As they come to life and their flowers start to emerge, they can be shunted into the spotlight and arranged among other mid-summer star performers such salvias, penstemon and astrantia. As they just keep flowering well into late summer, they can also be combined with late summer perennials like aster, rudbeckia and dahlia too. In early autumn, they can be placed where the low-angled sun can shine right through them and light up the panicles like fibre-optics. Having said that, my all-time favourite combo has to be a simple planting of pennisetum orientale and Gaura lindheimerii – delicate, impressive and altogether awesome. Don’t be afraid of these little beauties, give them everything they love and they will reward you with one of the most eye catching and impressive displays your garden has ever seen.