Ornamental Grasses - Their Place In A Dry Climate Garden

By Jonathan Ya'akobi

The use of grasses and grass-like plants in garden design is well established throughout the world. As they can solve a variety of design issues they are to be found in many different types of garden. While not specific then to dry climate gardens, ornamental grasses nonetheless provide the dry climate gardener with a number of exciting design options. These can be summed up as follows.

*Whether very low growing or billowing to 2 meters in height, they provide a sense of movement in the garden and a very definite vertical accent.

*By virtue of their feathery growth habit, a very clear texture is created in the garden composition, allowing ornamental grasses to function amongst broad-leaved plants as an emphasis element, or as a transitional element between fine textured plants, and courser textured ones. When placed amongst fine textured ornamentals which are not grass like, a subtle variation on the theme of delicate texture is created. In this way, two principles of good design are addressed - namely unity on the one hand (feathery texture) and variety (grasses and broadleaved plants) on the other.

*In dry climate regions where water is at a premium a few grasses can be dispersed in a bed of ornamental pebbles or wood chippings. With the addition of some stepping stones, such a configuration could replace a thirsty lawn and be aesthetically pleasing at the same time.

*They associate excellently with narrow leaved plants of outstanding sculptural value such as Yucca, Nolina, Dracaena, Phormium and Dietes. Therefore grasses of varying heights and shades can be massed to form the basis of a composition, playing a supporting role to a few special plants which function as emphasis elements. As the mass of grasses share a common leaf shape with the sculptural plants, the criteria of both unity and variety are again satisfied.

As previously mentioned, different species of decorative grasses vary greatly in terms of size and color. Here are a number of examples.

*The Pampas grass, Cortaderia selloana is suitable for large scale situations only. The real beauty is in the massive plumes that billow spectacularly from the foliage. The leaves of Pampas grass are serrated along their entire length, making the plant potentially dangerous. It should never be planted close to paths and entrances. A safe alternative to the Pampas grass could be the giant sedge, Cyperus papyrus

*Fountain Grass, Pennisetum setaceum grows to almost 2 meters, and also sports beautiful flower plumes. The main drawback is its tendency to disperse seed profusely, thereby becoming a noxious weed in certain circumstances. The purple leaved variety of the same species, 'Rubrum', does not seed itself and its foliage color is magnificent providing the plant is not over-used. It needs to be cut to the ground a couple of time a year and sometimes degenerates after a few years, but can nevertheless make a stunning contribution to the design. P.s.'Rubrum' covers about a meter in width, and therefore tends to smother neighboring flowers in an herbaceous border.

*Of similar size and habit is the Silver grass, Miscanthus sinensis. A number of varieties of the species have been developed, the most famous being the elegant M.s. 'Gracilimus'.

*There are a large number of low growing grass-like plants to choose from which are suitable in a herbaceous flower border, and indeed "hold" the bed for the period of time when annuals have to be replaced, or perennials cut down and rejuvenated. Examples are Liriope, Ophiopogon, the ever dependable Festuca, and various species of the sedge, Carex. Care should be taken though in choosing species that do not spread vegetatively and become a weedy pest. Some 5 years ago I added the cute and delicate Bulbous Oat Grass, Arrhenatherum elatius bulbosum to a flower bed, only for it to totally take over the border. It looked very nice, but my customer had enjoyed her flower color and so we had to spray the grasses to eliminate them before replanting the border. You have been warned!

About the author - Jonathan Ya'akobi. I've been gardening in a professional capacity since 1984. I am the former head gardener of the Jerusalem Botanical Garden, but now concentrate on building gardens for private home owners. I also teach horticulture to students on training courses. I'd love to share my knowledge and experience with you. So you're welcome to visit me on http://www.dryclimategardening.com

Article Source: http://EzineArticles.com/?expert=Jonathan_Ya'akobi

What is the Greenhouse Effect and the Importance of Methane to Climate Change

By Steve Evans

The greenhouse effect, also called the "greenhouse phenomenon" or "global warming", has recently been receiving a great deal of scientific and popular attention. The term refers to a cause-and-effect relationship in which "heat blanketing" of the earth, due to trace gas increases in the atmosphere, is expected to result in global warming.

By global warming we mean an increase in the average temperature of the planet. Actually global warming is rather a confusing term because global warming does not mean that everywhere will be hotter all of the time, it just means that on average the globe will be warmer.

Now we just mentioned that “heat blanketing” is taking place, and that this is due to trace gases in our atmosphere. There are a number of so called ‘trace’ gases, which simply means gases that are present in the atmosphere at low levels, such that there is only a trace present (a small amount in proportion to the other gases). So it is these trace gases that are producing an effect which is like wrapping the world in a blanket. Just like any blanket, it has a net effect which holds the heat in.

These trace gases are increasing as the result of human activities. Scientists know this. It is easily measured historically by analyzing things like pack ice which was deposited in layers which layers can be readily dated and go back hundreds of thousands of years.

Carbon dioxide (chemically shown as CO2, which is simply a chemist’s shorthand way of telling us that it is a molecule made up from two Oxygen (O) molecules to each Carbon (C) molecule), is a trace gas.

The principal gases in approximate order of importance, are carbon dioxide, methane, the chlorofluorocarbons (considered collectively) and nitrous oxide.

Carbon dioxide is the trace gas scientists believe is contributing most to the "heat blanketing" and currently receives the most attention.

However, Carbon Dioxide is not the only trace gas which is implicated in climate change and methane is another which some have estimated to be over a third as much as that of carbon dioxide.

Gas from natural sources, cows and other ruminants, and natural sources where natural decomposition by fermentation produces methane, all contribute to the blanketing which is the cause of the greenhouse effect.

However, human activity is also responsible for a lot of methane gas production and Municipal Solid Waste Landfills have in turn been recognized to be a source of methane which is contributing to the atmospheric buildup.

However, the magnitude of the landfill methane contribution and the overall significance of landfill methane to the greenhouse effect have been uncertain, and the subject of some debate.
But, as time goes on the evidence becomes stronger, and the fact of climate change is now accepted by the vast majority of scientists working in this field.

So, it appears that methane (using US waste generation data and remembering that the methane from United States landfills is a very large quantity) makes an important net contribution to the greenhouse phenomenon.

Landfill produces a lot of landfill gas which is largely methane. Measures to reduce landfill methane emissions are thought to be among the most economical steps which could be taken to address a component of this problem.

So now you know more about this subject, and we hope you appreciate the danger posed by uncontrolled climate change. We have explained, and hopefully ‘demystified’ some of these details – so now you can visit our web sites armed with enough knowledge to help you to find out more...

Steve Evans is a regular contributor of environment related articles. There are more essential details about climate change and the importance of methane at The Landfill Gas Web Site See also our New Blog about renewable power sources which do not cause global warming: Renewable Energy News