Also, garden fruits and vegetables can generally be left on the vine until the gardener is ready to eat them. This greatly decreases the energy needed to preserve produce (in refrigerated trucks, cooled grocery stores displays, and in the consumer's refrigerator).
Produce available in stores is bred to be transported and shelf stable - not to be tasty. This produce is often picked before ripe, transported "green" and ripened with a gas treatment. This means that is is frequently less palatable than home grown produce. Thus, people are much more likely to discard bland store bought produce than they are to discard better tasting produce they took the effort to grow themselves. As the song says - "there are only two things that money can't buy - and that's true love and homegrown tomatoes".
So, growing your own produce can decrease the greenhouse gases the come from refrigerating and transporting that produce - carbon dioxide, nitrous oxide, and ozone. What about methane? Methane isn't a pollutant released during typical food transport - it is actually the key component of natural gas and a fuel source. Methane is produced by the average person's garbage when organic matter is discarded into a landfill. In that landfill, there is insufficient oxygen for aerobic digestion so the organic matter undergoes a process of anaerobic digestion. This anaerobic digestion produces methane - which is thought to be a much more potent greenhouse gas than carbon dioxide. This methane is sometimes captured and used for energy, but frequently it leaks into the atmosphere.
How can methane production from household garbage be prevented? Composting can decrease methane production dramatically. A huge amount of household waste can be composted, from leaves and grass clippings, to coffee grounds and filters, to banana peels, melon rinds, eggshells, and even paper plates. What shouldn't be composted is animal products other than eggshells, (meat, cheese, etc), oil, or pet droppings (this last is vitally important).
Composting is something that happens naturally, and if you put the compostable materials listed above in a heap you would eventually find it turned into rich soil. However, you can dramatically speed the process up by turning your compost pile or buying (or making) a compost tumbler.
People have very little incentive to compost unless they have a garden in which to use their newly produced soil, so gardening and composting are great complements to one another.
Isn't gardening hard work, with tilling, watering under the hot sun, for hardly any produce? Not anymore! Two great advances have made gardening enjoyable, easy, and extremely productive in almost every climate. Raised bed gardening (popularized as "Square Foot Gardening" by the brilliant Mel Bartholomew) has eliminated the need to slowly improve and yearly till the soil. This was only half of the battle however - as watering the raised bed garden still took significant time. Then an even more brilliant device called the Groasis Waterboxx PlantCocoon (or Waterboxx) was used in raised bed gardens. This device, the Waterboxx, collects and holds dew and rainwater and slowly releases it to the roots of a growing plant.
|A Waterboxx growing Roma and cherry tomatoes. Although the Roma tomato was destroyed in a storm, the cherry tomato plant went on to produce over 1500 tomatoes in one growing season - all without ANY watering after transplanting outside with the Waterboxx.|