Friday, November 26, 2010

Grasses With More Than Just Passing Interest

This is the time of year where the contribution of ornamental grasses becomes not only more evident, but also more appreciated. Above is the 'Morning Light' Japanese silver grass (Miscanthus sinensis 'Morning Light') in mid-summer, offering texture and a nice anchoring point near this bench at the Chicago Botanic Garden. This is one of my favorite, taller grasses with very fine texture (narrow leaf blades). Whenever I've talked about ornamental grasses, I mention that although many have superior winter interest and while that may be their primary trait/contribution, they should also be good garden neighbors for other plantings and certainly have an interest during the growing season as well. I've been going thru many of my digital photos taken this year and am coming across lots of grasses that I saw in my travels. I've included only a few in this posting as this is the "tip of the iceberg" for what is available to the home gardener. Below is a strongly variegated Japanese silver grass (Miscanthus sinensis) called 'Cosmopolitan' seen at the New York Botanic Garden.
It is important to remember that ornamental grasses run the gamut in appearance, height and certainly cultural requirements. When we select a grass (or any plant for that matter) we have an expectation of that plant. Perhaps we want something with colorful leaves, scented flowers, wildlife value, food production, etc. Again, we have an expectation. However, remember that it is a "two way street" and that plant has an expectation of you. In regards to grasses, that grass expects proper soil, watering, placement in a preferred solar exposure, division, fertilizer?, etc. Knowing your grass in advance in terms of what it will do for you is fine, but also know what you need to do for that grass. Grasses might be termed low-maintenance by they are never no maintenance (what plant truly is?). Division of larger grasses is warranted after 3-5 years or may be indicated by a "donut-like" appearance in spring with a dead center and vigorous growth on the outer ring. Consider the inputs involved with the division process. Below is the golden wood rush (Luzula sylvatica 'Solar Flair'). This grass (actually a grass relative) provides a nice beacon of gold in a shady spot. We have this at RBG and I saw it on many of my trips. This tough perennial is drought tolerant and will adapt to a wide range of soils. It definitely needs some shade as it can get "crispy" with too much sun. Developments of new varieties of ornamental grasses continues in earnest. In many cases, new varieties are located when a chance seedling shows an interesting characteristic and is trialed to make sure this feature is "stable" and worthy of consideration as a new variety. Many of our native grasses have been used for decades over in Europe as landscape plants prior to them becoming more popular Stateside. A good example would be our native switchgrass (Panicum virgatum). Many varieties were developed decades ago (primarily in Germany) for having reddish foliage that becomes increasingly more red (and ornamental in fall). Many of these varieties were also shorter in stature as well, being in the 3-5' range as opposed to the 6-8' range like some of the bigger varieties. Below we have the 'Ruby Ribbons' (Panicum virgatum) switchgrass which is a new variety from Dr. Mark Brand of the University of Connecticut that has one of the old-fashioned red leaved parents and continues the tradition of being colorful and having shorter stature (3' or so). This looks to be a neat variety for sure.
Our gardens, while being able to include a wide range of perennial grasses, can also benefit from partially hardy or annual grasses for all the same reasons we select other varieties. Annual grasses may offer an interesting color or form and have extreme merit even for their short season of interest. We plant probably 1,000 annual grasses each year around RBG. They are in annual beds, containers, perennial borders, etc. Consider again the merits and needs of each variety. The grass directly below is pink muhly grass (Muhlenbergia capillaris) which I noticed at the New York Botanic Garden. This is the first time I saw it in bloom with those wispy pink inflorescences and was very impressed. I've seen its picture in catalogs and always assumed the pictures photo-enhanced. However, the hazy pink was extremely ornamental and although native to North America, has a zone 6 hardiness ranking. Darn it. The bottom photo is a maroon sugar cane (Saccharum officinale 'Pele's Smoke') that is bold, ornamental and that maroon is a wonderful foil for neighboring plants with yellow or white. I'll do a future posting on other annual grasses of merit. Do visually scout the landscape (yours included) this winter to see the value of grasses in the winter "scene" and note those areas that would benefit from including that interest in the future. Ornamental grasses are one of those "untapped resources" that hopefully will become more utilized by gardeners in the future.

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