Ornamental grasses are spectacular in the garden during any season of the year, but they show their full glory in the fall. Whether the two metre tall plumes of Saccharum ravannae with its silvery-tan seedheads are seen waving in the breeze or it is the yellowy-brown effects of the upright Caramagrostis seed heads that attract attention, ornamental grasses are on full display right now.
One of the best types of ornamental grasses to create a dramatic, group or accent display is Miscanthus sinensis. This beautiful ornamental grass is called Japanese silver or maiden grass. Of all the Miscanthus available, (of which there are plenty) one of the very best cultivars for a specimen planting is called Gracillimus. The plants form a well-defined, rounded clump that will grow outward at a manageable pace each year. Miscanthus are not invasive and can easily be divided if the clump gets too large. Gracillimus is a cultivar that has narrow green leaves that gracefully cascade from the upright stems. The plant has an attractive vase shape and grows to 1.5 metres in size. In the garden three clumps could be used effectively as a focal point against a fence. In the fall, upright, reddish-tan flowers appear. They look like sparklers or magic wands shimmering in the sun. The slightest breeze moves the blooms causing them to come to life. These flowers will soon turn into a beige seed head that is excellent if it is left standing through the winter. The fountain effect of the tan leaves and seed head against the snow is very picturesque during the winter.
Miscanthus is very easy to grow. Once established, generally the only time that they need attention is in the spring. This is when a quick pruning close to the ground is required. Using hedge shears, remove the over-wintering stems and seed heads before the new growth begins to appear. Many newer cultivars have made their ways to garden centres lately. Some are not as hardy as Gracillimus, others are shorter or taller, have different blooms or foliage and still others may have better fall colour. Gracillimus is still one of the favourites. Others that are worth investigating are Silberfeder (silver feather grass hardy to zone four), Grosse Fontane (large, silver fountain grass to two metres tall), Undine (a compact form for smaller gardens), Morning Light (has a narrow band of white down the leaves producing a shimmering effect), Malepartus (red flowered fountain grass with better hardiness), Sarabande (fine textured, silver foliage on a compact plant), Variegatus (variegated, green and white striped leaves) and Zebrinus (zebra grass with bright green leaves having golden horizontal banding).
Miscanthus are all warm season grasses that do most of their growing during the summer months. They tolerate heat and humidity extremely well. Blooming times vary from early fall to late fall among the cultivars.
The feather reed grass is also a favourite in the garden. In particular, Calamagrostis acutiflora Karl Foerster an excellent accent plant for the garden. This ornamental grass is becoming one of the most favoured of all the grasses (and for good reason). Karl Foerster was the winner of the Perennial Plant Association’s perennial of the year in 2001. It is very attractive in the garden and makes a great vertical living screen reaching 1.5 metres. It is one of the most versatile and like Miscanthus it has very little maintenance demands. Karl Foerster is a cool season grass so much of its growth is in the spring. The early start allows the flowers to appear early in the summer (unlike the late fall blooming time of some Miscanthus). The flowers begin with a white colour then fade to rose and finally transform to narrow golden-tan seed heads. Karl Foerster is forlorn just by himself. Use several plants to make a bigger impact using it as a strong vertical statement. Position this plant so that the late day sun can shine through the plant and make the seed heads glow. The deep green foliage is also attractive when it turns to tan at the beginning of the winter. One session of pruning and the maintenance is mostly finished for the year. Karl Foerster is reliably hardy to zone four.
A new and very exciting introduction is Overdam variegated reed grass. This relative of Karl Foerster has boldly striped green and white leaves which contrast well with the gold flowers and seed heads that follow in mid-summer. This ornamental grass surprisingly does well in heavy clay soils (of which Niagara has plenty). Overdam is a true four-season plant with exciting features all year long. In the summer, tall vertical flower stalks reach to one metre and produce feathery, pinkish-green flowers. As these flowers progress they turn a golden colour which fades to an attractive tan colour.
Stipa is an unusual grass that has had plenty of fame this past summer. Stipa tenuissima was used as the mane and tail for one of the three-dimensional plant sculptures at Mosaiculture Niagara. This Mexican feather grass was ideal as the life-sized pony’s hair because it has a fine airy texture perfect for this purpose. Stipa is a warm season grass that readily withstands drought. Masses of this grass tumbling down a hillside have the effect of rolling waves. Stipa needs excellent drainage during the winter to successfully live from year to year.
Another popular four-season grass is Panicum virgatum (red switch grass). This native tall-grass prairie plant has been bred to produce several excellent cultivars for the garden. One of the newest is called Heavy Metal. This has bright blue foliage through the summer with highlights of yellow and red in the fall. The seed heads are very fine in texture and have just a hint of beautiful burgundy colour. This grass is a warm season grass that is very drought tolerant and shows excellent hardiness too (zone three). Heavy Metal is also tolerant of moist soil conditions and can be very useful as a vertical accent in the garden. The flowers reach 1.2 metres in height.
Ornamental grasses are not the invasive, spreading thugs of the garden anymore. There are plenty that are graceful, clump forming and attractive the entire year round. One session of pruning these grasses to the ground in early spring is all that is required each year. Ornamental grasses are now coming to the forefront of the garden where they can show their true nature and provide exceptional displays of pink, silver, green and tan in the fall. Their winter effect is breathtaking as a beautiful stark contrast of tan foliage and seed heads against the white snow. Consider all the benefits that ornamental grasses give to the garden during each season.
Reprinted on the ICanGarden.com site with permission from Rob Witherspoon at Guelph Turfgrass Institute.
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