Pennisetum macrourum or African Feather Grass is a simply stunning plant, I bought two in September 2011 from Knoll Gardens to remind Hitesh and I of a memorable day out with Roger Grounds. He raised a knowing expert eyebrow at my purchase, but wisely left me to work out what the gesture meant for myself.
I was bewitched by the 6-8″ long cylindrical cat’s-tail-like flowers that are so soft and silky to the touch, opening a pale cream tinged with green, they age through to a pinky beige – they look great in flower arrangements whether freshly picked or in dried flower arrangements.
Even the cats seem to agree, these days it’s all too easy to be distracted by flowers, but back in 2011 the first clue that raised my eyebrows was the mat of roots encircling the bottom of the pot ….
Evidently, this was a grass that might need watching, if used with a little care, it could be a great addition to the garden. Gardening in a field, as I describe it, makes me look kindly on plants that can give the cooch grass and creeping buttercups a run for their money. Like many grasses, pennisetum looks stunning grown en mass which for me means it must be easy to propagate in order to afford the numbers required. Failing that, it looked as though this statuesque pennisetum would excel as pot specimens on the terrace. With roots like boot laces, it didn’t seem the sort of thing to add to a mixed planting of delicate treasures.
Four years later the pair planted in a sunny spot either side of the little bench are mature at a height of about 5 feet in flower. Admittedly the bench is swamped by a profusion of flowers. I plunge-planted the two 2 litre pots in 50 litre bottomless plastic containers to act as cuffs against wayward growth and they’ve behaved impeccably. (Cutting a vertical slit in the pot makes it much easier to wrangle plants out of the ground). Although the holes were back filled with John Innes number 3 plus lots of grit, the underlying soil in this part of the garden has pockets of sticky greenish-blue-grey clay, the sort that whiffs of something nasty.
The silvery foliage is a sheer delight. Reading about Pennisetum macrourum I came across queries regarding its hardiness, when I read in a seed catalogue that its cousin Pennisetum macrourum ‘Tail Feathers’ might be best ‘grown as annual’ the alarm bells sounded. I’ve had miserable experiences of loving and loosing too many related species, most memorably the tender but gorgeous burgundy leaved, red flowered Pennisetum setaceum ‘Rubrum’ as well its apparently half-hardy cultivar ‘Fireworks’.
Despite all my efforts to overwinter ‘Rubrum’ in the cosy greenhouse, it’s either died or looked sickly the following year. Lots of pennisetums are fully hardy in most parts of the UK, sadly this isn’t one of them, not at least in the damp Welsh borders, but if I bump into a good one I’m likely to swoop it up as an annual treat.
I’ve a growing collection of another borderline hardy one, Pennisetum villosum, which in my dreams and more southerly gardens drips with these beautifully fluffy cream flowers. It frustrates me for overwintering so well in the greenhouse that they have to be divided each year, but even between several large pots only produce a handful of flowers.
This year despite villosum enjoying the sunniest west wall against which to bask the late August display is hardly floriferous. I live in hope, after all, some species of pennisetum are especially late to flower and I can see lots of villoum’s emergent flower spikes – despite the overcast weather they are still bravely flowering. Late flowering in itself doesn’t make a plant ungarden-worthy, in fact, it may be an asset. The foliage of Pennisetum villosum is a pleasant mid-green but in cool grey climates it takes quite a long time to form these lax mounds. Even so, I haven’t the heart to folllow the advice of “When in doubt, throw it out!”. At this rate I’ll end up with a flowerless field full … and a polytunnel?
In comparison Pennisetum macrourum never looked like a pernickety plant, its strong fountain of strap-like silvery grey-green leaves looked and felt resilient enough to take its chances in the nursery for the winter. Given the cold, wet winter with temperatures down to -10 I was surprised to see both plants had made it through unscathed and still had lots of green leaves.
Perhaps it hadn’t read its care label, coming from South Africa where it’s known as the Veld Grass, it’s not meant to withstand less than -5. Maybe this is a bit conservative, especially for mature plants? All things considered, I was impressed and encouraged, who knows, maybe next year I’ll let it run free?
It raises eyebrows too, for all the right reasons.