ORNAMENTAL GRASSES NOW A STRIKING MAINSTAY
Twenty years ago, ornamental grasses were garden novelties used mainly by professional designers and plant aficionados, but that changed rather quickly as more became available, and today, they are mainstream wonders. Now, we see them everywhere — dressing up designer containers, planted along highway medians, meandering as drifts in larger landscapes and starring as focal points, even in small space gardens.
Ewan MacKenzie, one of the most passionate wholesale growers of ornamental grasses, owns Exemplar Horticulture Ltd. in Abbotsford. So he was an easy target for my questions about these landscape beauties.
Why should folks use grasses in today’s very multi-functional garden settings? “There are so many reasons,” he said, “from their different forms and textures to their hardiness and drought tolerance. They add something special to any garden and to keep them exciting, there are lots of new varieties.
“There is, in fact, a top 10 list of grass families that just never fail to impress. The carex family is, perhaps, the most sought after because they are great for small spaces and containers, and they come in such a diverse array of varieties. Carex ‘Evergold’ is widely used for its vibrant colour and year-round interest. The ‘Evercolor’ series provides a wide selection of interesting foliage.”
I mentioned to MacKenzie that my personal favourite is the hot lime C. ‘Everillo’ that thrives in the shade and is even more vibrant in partial sun. He agreed that it’s a good one but said there are so many other great choices in this family worthy of any garden. MacKenzie described other ornamental grasses that he most admires, and what follows is a summary of his comments and of the varieties he recommends.
Calamagrostis ‘Karl Foerster’ with its narrow and tight architectural form and interesting seed heads is winning much praise. C. ‘Overdam’ and C. ‘Eldorado’ have striking variegated foliage, making them not only beautiful but they also fulfil that similar architectural look.
Japanese forest grass, Hakonechloa, is enjoying huge popularity, especially for shady areas. Surprisingly, it does particularly well in dry shade, especially under trees where many other plants struggle. Its soft graceful foliage creates a lovely understudy for so many trees. The gold and variegated foliage varieties are particularly vibrant.
Pennisetums are beginning to flower now in many gardens, and because of their ‘bunny tail’ plumes that dance in the wind, they are really in demand.
The most popular of all pennisetums is ‘Purple Fountain’ grass which is an annual, lasting only one season. There are many other varieties that are very hardy and have exceptional flower heads. Pennisetum alopecuroides ‘Hameln’ is the older standard of excellent performance; P. ‘Moudry,’ as it matures, has stunning large burgundy plumes; and P. ‘Red Head’ has beautiful reddish plumes.
Panicum grasses, often known as switch grass, have also jumped to the forefront because of their interesting foliage. ‘Shenandoah’ has rich red-burgundy foliage in October, and ‘Cheyenne Sky,’ ‘Prairie Fire,’ ‘Blood Brother’ and ‘Little Red’ are quite striking as well.
So, what about the reds and blues? How are they faring ? MacKenzie’s response was “Red grasses, such as the Japanese blood grass or Imperata cylindrica, are always hot. Imperata generally does not flower in our climate, but I have seen it flowering more frequently in recent years with tan coloured flower heads that make a nice contrast to the red leaves.
“Blue fescues,” said MacKenzie, “are extremely popular not only for their blue colouring that contrasts so beautifully in the landscape but also for their great drought tolerance. ‘Beyond Blue’ is one of the bluest varieties, but ‘Pepindale’ and ‘Elijah Blue’ have always been great performers.”
What would be a really big grass to use as a statement feature? “Miscanthus are impactful landscape plants.” said MacKenzie. “Tall grasses afford lots of privacy, and the 10-foot high Miscanthus giganteus is in a class by itself when used as a foliage barrier, but it usually doesn’t flower because it needs a very long season.” ‘Harrison Yellow’ has interesting green and yellow foliage. ‘Zwager Elephant,’ with its broad, strap-like leaves and very large flower heads, is particularly nice as a backdrop.
Mid-sized miscanthus make great background plants, especially when the plumes are showing in late July through September and October. When I mentioned that I loved the beautiful dark foliage of M. ‘Ghana,’ MacKenzie recommended the unique M. ‘Ferner Osten’ with its dark flowers.
The smaller miscanthus like ‘Yaku Jima’ and ‘Little Kitten’ are nice accent plants for containers or in small spaces. ‘Morning Light’ is a little taller and looks quite elegant with its narrow variegated foliage.
I agree with MacKenzie that these are terrific miscanthus varieties, but I also love the richly variegated white and green foliage of M. ‘Cosmopolitan.’ It has vibrant, wide shiny leaves that look great from a distance.
MacKenzie shared another interesting bit of news about miscanthus. “We have been hoping for a hardy version of ‘Purple Fountain’ grass for years, and I think we have something that is very close in Miscanthus ‘Little Miss.’ It is probably the most compact miscanthus out there, with foliage growing to 24 inches tall and flowers rising 12 inches above the foliage. The real attraction, however, is that the foliage emerges green in spring, then quickly turns dark burgundy by midsummer, and it is hardy to zone 5.”
Is pampas grass still relevant in today’s gardens? MacKenzie said it is still popular, but it is sometimes considered an oldfashioned grass. Most varieties are tender (zone 7), but there are hardier ones, like Cortaderia ‘Patagonia,’ which is an early-flowering variety that plumes up in May or June. ‘Pumila’ is also quite hardy. MacKenzie cautions that they all need space because they do grow big. Pampas should be cut back at the end of March or early April, and because their leaves are sharp, MacKenzie recommends wearing gloves and a longsleeved shirt.
All herbaceous grasses can be cut back when they start looking unsightly after a storm or heavy wet snow, but don’t be in too big a hurry because many will bounce back.
Summer is a great time to introduce ornamental grasses to your garden or containers. All grasses need well-drained soil because most of them hate wet feet, and they should not be planted too deep as that could cause their demise. When you mulch grasses, do it lightly. Also, grasses are stronger without fertilization. For the best success with grasses, they should be divided every five years or so. At the end of winter, dig them out and with a serrated knife or pruning saw, cut them in big chunks that can be planted back in the landscape.
Ornamental grasses are a great source of cut flowers. For best results, when you pick the flowers, put them in water for a few hours, then arrange them in a vase without water.
MacKenzie suggested lighting our grasses at night by using LED spotlights at their base
— a brilliant idea I had never considered. He said that both the plumes and the foliage look spectacular.
So, where are grasses trending in the future? According to MacKenzie, “as watering becomes more of an issue, grasses will continue to play an important role in commercial and municipal landscapes.”
“Today, we see medians between roads planted with more and more grasses, especially the fescues, and for folks who would like to see more colour and impact in their gardens, grasses will continue to provide that. Often, they are very much the wow factor.”
I’d like to express a huge thank you to Ewan MacKenzie and his great staff at Exemplar Horticulture for growing and showcasing so many wonderful old standby grasses and the many new exciting head-turners being introduced today.
Brian Minter writes on gardening every Saturday in The Vancouver Sun.