Summers are the time when we think about vegetables and gardens -- and all the expensive fertilizers homeowners use to make sure they grow big and bug-free.

Residential gardens and lawns are a mixed blessing. On one hand, having greenery in the heart of a city in summer keeps ambient temperatures lower. In a well-treed city, it might be 10 to 15 degrees Fahrenheit cooler under the leaf cover than it is in an open field or a traffic artery.

Growing things require nutrients, and that's easily provided by composting household food scraps and plant material. Today there are millions of North Americans composting materials that would have gone to land fills a few years ago.

But there are dangers for society as a whole in that "idyllic" lawn and garden: fertilizers, herbicides and pesticides are not, in the total picture, good to Mother Nature. Especially when you consider the scope of the problem.

Use of these chemicals is split between farmers and people outside of the agricultural industries -- including homeowners. A 1983 study found that an average suburban household in Illinois used 8.1 pounds of pesticides per acre, compared to 2.1 pounds per acre for neighboring farmers.

Think about the number of plastic bottles or tin cans of chemicals sitting in the garage, waiting for a particular bug or disease to crop up. The average household will have anywhere from three to 15 different containers, some full, some empty.

The chemicals were used to "control" bugs or weeds, or to make tomatoes bigger and redder.

They're spread with a vengeance over that 10' x 20' plot of garden, in far higher concentrations than any farmland.

Now, think about the infrastructure that's needed to produce all those chemicals -- the mines for raw materials, the huge plants and their energy-gobbling machines, the trucks and trains that move products to market. Consider the resources needed, just so the homeowner doesn't have to worry about wilted radishes.

Strangely enough, the greater the use of chemicals to control weeds or insects, the more they change and adapt. It's not unusual to drive down a country road, spot a field of billowing barley, and ponder why there are six tall weeds in the middle of an otherwise pure stand of grain.

The "weeds," the undesirable plants, have adapted to the chemical onslaught farmers have thrown at them. If that happens when chemical use is sensible, what happens when an unthinking homeowner pours gallons of weed killer on a plant?

Chances are it'll adapt and mutate, and become even harder to kill.

Which suggests that perhaps there's value in going back to the "old ways," when weeds were dug out by hand, where grass clippings around garden plants stopped undesirable growth and reduced insect infestations, and where real attention was paid to the plants.

Compost is natural fertilizer and its value should never be ignored. It's produced by natural things, like trees and grass, which provide their own benefits: compost is a beneficial by-products.

Consider investing in a compost bin. if you're hesitant about the initial cost, figure out how much you paid for all those chemicals in the garage. It'll be a lot more than the cost of a compost bin.

And your vegetables will taste better for it!