From the Weather Channel, of all places, I recently learned that I've been growing the next great energy fad, completely unaware for the past 10 years of the potential gold I could be harvesting from my landscape. I'm referring, of course, to the recent spate of news reports which herald the enormous biomass production capacity of Arundo donax. Evidently, some biofuel investors in North Carolina have discovered that Arundo can produce up to 20 dry tons of foliage/acre, far ahead of its closest competitor, and they plan to join with Chemtex International to build a production plant for synthetic fuels made from the grass.
Gardeners who aren't into Latin may not recognize the name Arundo donax, but I assure you that all of you would recognize it by the common name, 'Giant Reed' grass. I've grown the variegated form of this grass for the past decade as a better-adapted substitute than pampas grass to camouflage our septic tank from view. In Kansas, it grows approximately 10 feet tall each year with absolutely no care or extra watering, and it maintains a decent appearance until late in the Fall. My feelings have run both hot and cold for Arundo as long as I've grown it. I admire the easy-care maintenance of the grass because it requires only cutting it back to the ground each spring; no extra water, no fertilizer, no shaping. It stands up to the strongest summer storms. On the other hand, even the variegated form is so uninspiring that I've never taken a picture of it. Ever. I can't even show you a picture of it as it appears right now because I've already cut it to the ground for the winter. It is planted on the far edge of my garden so it doesn't even appear in the background of garden pictures. The picture above, cropped and blown up, is from a wider view of my back garden and it at least gives you an idea of the clump of Arundo in my garden, separated from the rest of the garden by a good margin. This far away, you can't even see the variegation, just the tall, maize-like nature of the plant. Arundo just sits there each summer, a tall blob in my landscape, too stiff in the wind to provide any interest or motion to the garden, uninspiring in flower, and dull brown in winter. Who would think that it had any real value as a production plant?
The danger to the ecosystem, of course, is that Arundo donax has naturalized in 25 states and it is considered a noxious weed in California and Texas where millions of dollars have been spent trying to control it. Are you surprised that a plant that grows so large so easily might become a bully to some poor little Monarda? Some experts fear that Giant Reed could become the next kudsu, out-competing native flora in a apocalyptic expansion. My only contribution to the discussion is that my clump has not yet escaped the confines I've given it in my garden, nor have I seen it crop up in the native pasture. Seeds are supposed to be sterile, but it can spread from every node of a green plant if it gets broken off. I suspect the danger for spread would be far greater in areas where grazing animals trample it and help to spread it.
Some of you will want to try Giant Reed in your landscape, and if you do, I've got plenty of starts that are guaranteed to grow, so just come on by. I can't, however, provide you a decent picture of the plant until next fall, when I'll try to keep a mental note to specifically photograph the plant. Until then, take my word for it, it will never be the star of your garden although it may someday fill the gas tank of your car.