The next time you wash your car at your suburban homestead, do it in the yard. Park your car in the front yard like a redneck and help conserve water that would normally run down your driveway, into a storm sewer, and on to the ocean. Instead, your spent, soapy water goes back into the ground at a place where it’s needed–your lawn. The grass (and surrounding trees) will benefit from the water and a little soap is actually good for the grass and soil. Just ask Jerry Baker.
I recently attended a lecture by James Urban based on his book, Up By Roots. Mr. Urban is a landscape architect who has devoted the better part of his career to understanding trees in the urban environment. In his lecture, Mr Urban described his understanding of soils based on research and years of field observation. His premise is that not nearly enough attention is paid to soils in preparing a site and maintaining it for plant growth, especially for urban trees.
In his lecture and book, he talks extensively about the positive role of compost in developing and maintaining good soils for plant growth. Adding good compost to any soil introduces biological processes which help improve the quality of the soil. In hot, humid climates, like Jacksonville, Florida where I live, compost basically evaporates at a surprisingly fast rate. Therefore, in these climates compost must be added more frequently. Yet, a surprisingly small percentage by volume is desired within the soil itself, ideally about 2-4 percent in healthy soils. New compost is added at the surface to established plants, perhaps 2-3 inches deep. The biotic activity works downward from there. He questions the need for commercial fertilizers and suggests compost is almost always a more appropriate method for establishing and maintaining plant health.
Mr. Urban’s well-documented findings support my argument for maintaining a suburban compost system and expand the list of benefits it can provide.
Three Compost Bins
As a Jacksonville, Florida landscape architect, I admire Louis Sullivan’s maxim, “form follows function.” And while I believe the design process is really one of balancing the two, not relegating one behind the other, my construction method for a suburban composting system is heavy on the function, light on the form.
Given its role and location at the rear corner of my lot, I haven’t put a lot of effort into its aesthtic treatment. In fact, my focus was on a design that was as simple as I could make it and using the cheapest possible materials, but with durability in mind.
4×4 posts anchor the corners and are not treated. I don’t care if I have to replace them in 10 years; I’d rather not have the wood preservatives in pressure-treated wood leach into the compost. The slats are standard cypress or cedar fence slats, the cheapest I could find, often culls. I used 2x4s nailed to the existing wood fence (which serves as the back) as needed to attach the slats to where a post wasn’t convenient. I spaced the slats out about 1.5 inches (the width of a 2×4) and carried them up about six feet, though I’ve yet to get a pile that high. Five feet would probably work fine. Caps on top of the 4x4s would dress the bins up and help extend their life. The fronts are left open for access, but I used 2x2s nailed to the 4x4s to create slots for slats that can be inserted as needed to enclose the front. All of this in constructed with a handsaw (albeit a Japanese Ryobi, which is the bomb), a hammer, some leftover nails, and a level to keep the posts vertical and the slats horizontal (for stability and aesthetics). Perforated PVC pipe sections laid under the pile help speed the process by allowing oxygen to get under the pile. That’s on my list of things to do.
This system can serve most suburban houses, along with multifamily complexes and commercial and office sites.
Empty bin
First bin with new material
Bin with finished compost
My composting system is simple but effective. It is a three-bin system which allows for enough separate space for rotation and storage. Each bin is about four feet wide and five feet deep. All of them are about 5 feet tall. So the total area is about twelve feet by five feet.
Usually, I keep two bins active and reserve the third for finished compost, ready to use when I want. Once one bin is filled with fresh material, I will begin filling the second. As I fill the second, I add some material from the first to cover, an important step in keeping critters away. This also helps rotate the piles and adds partially composted material to the new, speeding up the process. Eventually, one bin is advanced enough to let sit and finish. By that time, I’ve usually used up the completed compost which frees up a new bin to keep the process going.
The finished pile may need to be flipped once or twice to make sure it is thoroughly and evenly composted. It will depend on what you want the finished product to be. I’m not bothered by a coarse mixture, but many will take the extra step of screening the finished compost through construction fabric to get a really fine compost and return the coarse material to an active bin.
My next post will feature some photos of my compost bins and describe how I built them using a simple method and cheap materials.
I don’t know why everyone who owns or manages a property doesn’t have a composting system. Composting is a major component in creating a sustainable landscape, and it’s easy. Recycling plastic and glass has gained momentum over the years and we now wear jackets made of old Coke bottles. The same process (and rationale) applies to organic materials.
Pretty much anything that was once living can be composted. Probably the most important for the suburbanite like me is yard waste. The City of Jacksonville (Florida) does have separate pick-up for yard waste that is composted in some manner, which is laudable. However, a sustainable practice involves creating a circular system where inputs and outputs balance as near the source as possible. When leaves fall in a forest, they aren’t raked up and deposited miles away, they fall near the tree it came from where they create a natural mulch that protects and feeds the roots as they decay. That’s a sustainable process.
In addition to yard waste like grass clippings and leaves, kitchen waste can easily be added to the compost. Kitchen waste, like leftover green beans, mouldy bread, and used paper napkins, accounts for a large percentage of our garbage. Putting into the compost system keeps it out of the landfill and adds a lot of nutritive value to the compost itself.
With a good system, it’s easier than taking out the garbage. The sustainable benefit comes when the compost has matured and is then spread over existing plants, used for potting soil, or used to nurture a vegetable garden. In the latter case, the vegetables once eaten, complete the circle.
To share my own approach as a landscape architect, my next post will describe my design for a suburban composting system that can be adapted to a wide variety of situations.
Mulch is probably the single best material you can use in creating a more sustainable landscape.
I use mulch as a placeholder. I have a design for my yard that cuts the amount of turf by half, reducing the maintenance requirements and making the lawn look better at the same time. As a cheap way to prepare the enlarged beds and establish the look I want, I lay a 4-6″ layer of mulch directly over the grass and use a weedeater to cut and maintain a new bedline. I use Roundup to spot spray the grass that survives and pokes through the mulch. By the time I’m typically ready to plant, most if not all of the grass is dead and possibly decayed, adding valuable organic matter to the soil.
I hate buying mulch and scavenge what I can instead. I am blessed and cursed with pine trees in my yard, so I get plenty of pine needles that I periodically rake up and use. Also, there is a storm drain in front of my house that collects a lot of leaves and detritus that I use as mulch, courtesy of my upstream neighbors.
Mulch keeps down weeds, preserves soil moisture, adds organic material to the soil as it decomposes, protects plant roots, and creates a neat appearance when uniformly applied. I prefer natural mulches in natural colors and truly hate red and other dyed mulch.
Sustainability has become a common word in the green movement vocabulary. But what does it mean, really?
As a landscape architect, I have studied sustainability in theory and applied its principles in projects over the years, hoping that my designs will help counter the adverse effects of our consumptive human behavior. Too often, I’ve not seen the results. Either the project didn’t get built, or its sustainable attributes just weren’t obvious.
I thought it important to engage on a personal level with what sustainability means as a landscape architect and as an average suburban homeowner. Walking the Walk is about exploring simple things that make a positive difference to me individually and that if done collectively, would make a very big difference globally.
