Grasses and flax

Grass acts in the border

Stipa gigantea and Carex
Stipa gigantea and Carex, December 2014

I’ve grown to love grasses. Like many children of the 70s, I hate pampas grass stuck in the middle of a lawn – they remind me of flares, vinyl car seats on a hot day and Spangles.

With the influence of designer Piet Oudolf’s prairie planting, grasses became THE plants to have during the last decade. Trouble was, you needed a prairie-sized garden to get the full impact.

Like all good things, there’s a middle way. You can easily introduce the odd tall grass, like Stipa gigantea for vertical interest and movement.

I find the small evergreen grasses (40-60cm) most useful in winter. They give shape, structure, and colour on the grimmest of days.

Blue fescue grass
Blue fescue grass

My two favourites are blue fescue grass (Festuca glauca) and a variegated sedge (Carex oshimensis Evergold).

There’s a group of Carex Frosted Curls (I think), which are silvery green and really catch the breeze.

An oddity is the corkscrew rush (Juncus effusus Spiralis), which produces medium green stems that curl in a spiral pattern. It grows best in full to partial sunlight and moist, nutrient-rich soils. However, I tired of this and brutally gave it the chop.

Variegated ribbon grass
Variegated ribbon grass

Another useful variety, taller at about 1m, is variegated ribbon grass (Phalaris arundinacea Picta) – however, it spreads quickly and can be invasive. It will thrive in just about every garden situation.

Miscanthus sinensis Zebrinus, or the zebra grass, takes its name from the horizontal cream bands on the leaves. Striking, silky, finger-like flowers bloom in late summer and stay on during winter. It grows to about 1.25m.

Tall at 2m, Miscanthus sinensis Kleine Fontäne has narrow, silvery leaves with a white stripe down the centre. It flowers right into autumn when its new, reddish-brown, tassel-like flowers are a foil for the faded, silvery older ones. Excellent for winter presence. Mine is struggling in the front garden, but it is made of large gravel 18″ deep – wouldn’t you?


Get your oats – Stipa gigantea

Stipa gigantea on a soggy August day
Stipa gigantea on a soggy August day

Nothing rude here, I’m talking about Stipa gigantea (giant golden oats), one of the largest feather grasses.

I’ve got a couple, one in the border, with a bit of added grit for drainage, while a small division is establishing itself in a planting pocket at the side of the gravel drive.

They flower from June to August and the panicles hang on well into winter.

They are hardy to at least -15°C. Once growing well, you just need to cut back the foliage during the winter to tidy it up before the new flush of growth appears – well, that’s the theory.

I haven’t read anywhere that Stipa gigantea leaves are addictive to cats. They are to George anyway.

When the big one was young, as fast as it grew, he nibbled them off.


Flax for the support

Phormium contrasting with Berberis
Phormium contrasting with Berberis

I’ll never complain about New Zealand flax (Phormium) again (see venomous article below).

It upset me because it’s crowding out the weeping cherry tree, but its flower spikes are superb – 8ft or so high, lots of them, with exotic, dark-red blooms which look a bit like small bunches of pink bananas.

Bees and other pollinators love it – it’s always covered in them. The best thing about these flower spikes is that they’re on tough, woody stems, which I leave on all winter for a bit of structure.

Unlike the fibrous leaves which are a nightmare to cut (resort to a pruning saw), the flower stems will snap off at the base in spring, leaving you with a strong structure which is great for making bean poles, or growing climbers up.

Flower buds of Phormium
Odd flower buds of Phormium resemble pink bananas

Meanwhile, written in 2013…

“Never smile at a crocodile…” Never fight with a Phormium, more like.

This stalwart of architectural planting, with its 6ft, exotic strap-like leaves, and Triffid-like 8ft flower stems, is a horror to keep under control.

Even if you don’t garden, you’ll recognise huge groups of them in council planting schemes, in the middle of dual carriageway roundabouts. They’re stunning statement plants but have suffered from overuse.

Of course, everyone who bought one when they were “new” and “fashionable” now has this massive clump of sword-like leaves to contend with.

While I didn’t want to dig mine out (a near-impossible task, according to people on Twitter), a trim was in order.

New Zealand flax (no relation to the European kind) has been used for thousands of years by Maoris for cloth, rope and baskets because of its incredibly strong fibres and that’s what makes it so damn hard to cut back!

Phormium flower stems
Me and my runner bean poles, made from Phormium flower stems

A sharp pruning saw just goes through the pulp of the leaf, leaving the fibres nearly intact. The best solution with living leaves is to cut them with anvil secateurs.

The raw, cut-back stumps are very unsightly, so I’ve solved this by growing a variegated ivy around its base.

You can pull dead leaves out from the crown, but beware – some of them come away easily, some don’t. It puts a massive strain on your lower back, which is why my flax is neatly trimmed three-quarters of the way around until my lower back went.

Still, I can probably make a support girdle with those useful fibres…