Fountain Grass Magic
Neil Lucas

I am sure that most of you will understand what I mean when I say I have been getting interested in the genus Pennisetum for some time now. You will know how it happens, gradually a group of plants gets your interest, you then discover (almost inevitably), that there are many more than you first thought. Then finally the magic is woven and you become entranced with your particular subject.
This is how it was for me with Pennisetum, a grass of warmer regions with the very appropriate common name of Fountain Grass. Of course being something of a plantaholic this is not the first – and hopefully will not be the last – time I fall under the spell of a group of plants. When I moved to Knoll I became very interested in grasses as a group of plants both for the nursery as a sales crop but especially for their use in the garden. There are so many different grasses but the ‘fountains’ with their wonderful gracefully arching bottlebrush like heads of flower always took pride of place for me. From my trips to the USA I was able to see how they were used; planted informally and frequently ‘en masse’ and so began the slow process of importing the ones I liked, which of course was most of them. I think our collection of Pennisetum is now probably the most extensive in the UK and I was especially delighted when it was accorded National Plant Collection status in November 2002 by the NCCPG. Being a warm season grass, that is one that comes from a warmer part of the world and so not too keen to start growing here until late in the spring, we cannot exhibit most of our collection until usually about Hampton Court Show time in early July. However one very noticeable exception is the purple fountain grass Pennisetum setaceum ‘Rubrum’, a West African species which literally flowers all year round if given winter protection. All parts of this ‘fountain’ are purple, including the flowers, which are elegant and sinuously reddish purple produced in continual profusion. A perfect summer specimen.

Pennisetum have an amazing flower structure, the inflorescence is botanically a false spike, the spikelets surrounded by a ring of slender bristles combine to give the ‘foxtail’. Morning dew or frost in autumn seems to enlarge the flower size even further. The deciduous grasses are best cut back in the spring, ideally just as the new shoots are coming through. Evergreens just need a tidy up.

Other varieties worth a try are:

Pennisetum ‘Fairy Tails’ Superb new fountain grass having strongly upright habit and masses of delightful light pink flowers fading to tan and beige produced over a very long season from mid-summer onwards. Sunny well drained spot. Height 90 cm – 1.2 m.
Pennisetum alopecuroides ‘Hameln’ One of the best for general garden use. Good partnered with Verbena bonariensis. Superb compact form with dark green wiry foliage and many fuzzy catkin-like flowers turning a golden autumn colour. One of the most reliable flowerers for the UK climate. Sunny spot. Height 80 cm – 1.1 m. Deciduous.

Pennisetum orientale ‘Karley Rose’ Extraordinary cultivar forming mounds of shiny arching leaves and deep rose pink spikes during summer. Looked fantastic in the border that we supplied plants for at Wisley. Sunny well-drained spot. Height 90 cm – 1.2 m. Deciduous.

Pennisetum macrourum Gradually spreading mounds of green foliage with many distinct arching stems topped with rounded off white flowerheads during summer. Wonderful. Sunny well-drained spot. Height 1.4 – 1.7 m. Deciduous.

Pennisetum ‘Paul’s Giant’ Particularly distinctive form selected in the USA for its large relatively tall spikes of typical fluffy flowers with good yellow orange autumn foliage. Sunny well drained spot. Height 1.2 – 1.5 m. Deciduous.

Pennisetum thunbergii ‘Red Buttons’ Bright red button like flowers on dainty narrow stems appearing to float above mounds of green foliage. Flowers fading to beige with age. A real stunner! Sun, well drained soil. Height 80 cm – 1 m. Deciduous.

Pennisetum setaceum Stunning, gently arching long fluffy reddish pink plumes on tidy mounds of narrow green foliage from midsummer onwards. Sunny well drained soil. Not reliably hardy in the UK but can become a significant weed species in some areas. Height 70 cm – 1m. Deciduous.

Pennisetum villosum Beautiful plant with clumps of light green foliage and masses of the largest and fluffiest caterpillar like spikes colouring buff white. Dramatic in full flower when planted in a pot or ‘en masse’. Sunny spot with good drainage. Height 50 cm – 80 cm. Deciduous.

First published in the Half Hardy Group Newsletter Spring/Summer 2009
and subsequently in Cornucopia Issue 25
© Copyright for this article: Neil Lucas

This article was taken from a copy of Cornucopia that was published in 2010. You could be reading these articles as they are published to a national audience, by subscribing to Cornucopia.