Ornamental Grasses

Gary Westlake


This time of year, I think of ornamental grasses because it's just about time to cut them down. We leave the dead stalks up throughout the winter, partly to feed the birds and partly because they look great. The dead grasses also catch the snow that protects your plants through the winter. Even though there might be a foot or two of snow, you still know there is a garden there because the grasses.

If you don't cut out the dead foliage and flower stalks now, the new growth will start growing through it and it will become just about impossible to do without sacrificing the new growth. We just grab big handfuls and chew through it with pruners but I have heard of those who tie a large clump together and go at it with a chain saw.

Ornamental grasses are a wonderful addition to your garden, if you have not tried them before. The best ones to use are the ones that form clumps, growing slowly out from the centre. You may have to wait a few years before they show you what they can really do for you but it is well worth the wait. They add a texture to the garden that you cannot get with any other group of plants and they add movement. The slightest breeze will send the thin blades of grass and flower stalks dancing.

There are some grasses that are not as well behaved because they spread beyond the original clump and wander causing all kinds of trouble for you. Ribbon grass is one of the worst of these garden thugs. Ribbon grass has its place in difficult areas where it can be contained but if you use it, be careful it does not move out into natural environments. Other 'assertive' grasses are Blue Lymegrass and Cordgrass.

There are two kinds of ornamental grasses. Some start growing when it is still cold in the spring but others wait until it warms up and are at their best later in the summer.

One of my favourite cool season grasses is Blue Oatgrass. It is a strong clean looking grass that does not get too tall and has great looking flowers that stand well above the folliage. There are two ways to look after it. You can carefully pull out the dead leaves in the spring or you can just shear it off and live with it that way for a few weeks until it grows back. Blue Fescues have a similar but softer look.

There are several warm season grasses that are great to use as well. Try Feather Reed Grass, 'Karl Foerster'. The flowers stand straight up 3 to 5 feet high. Also there are several varieties of Miscanthus that form grand displays in late August with large plumes 3 to 6 ft above the foliage. There is even one with bands of yellow across the leaves. There is a variety that is enormous (Miscanthus sinensis 'Giganteus') reaching 12-15 feet tall.

Most grasses prefer full sun but Northern Sea Oats will take a bit of shade. It has flat green seed heads that turn a rusty tan and last all winter. Also, Purple Moor Grass will take light shade. The variety 'Skyracer' sends up flower stalks 5-8 feet high well above the folliage.

Switchgrass (try the variety 'Heavy Metal') is a vigourous grass with upright and open clumps of delicate flowers that form a haze-like appearance above the foliage.

One of our favourites is actually an annual fountain grass (Pennisetum setaceum 'Rubrum'). It has wonderful red foliage with green at the centre. We plant it in the garden each year and dig it up in the fall. We split the clump into 2 or 3 and stuff it into large pots. We let it go relatively dormant inside until early spring when we start bringing it back to life with more water and higher light levels.

This year try some of these ornamental grasses. Get as big a pot as you can afford and they will come along sooner. You will not regret it. In fact, you may find that you are looking for more space to put grasses that so easy to grow.