Bear with me this morning. I promise I'll get to the global warming part, it just will take a few paragraphs of setup first.

One sunny Spring day about 15 years ago, I got tired of looking at the weed-choked, trash-strewn vacant lot across the street from my first-floor apartment. It was a blight on the neighborhood, and though most of the adults complained about it, no one did anything about it. That morning, I decided that I wasn't living across the street from that any longer, so I grabbed a roll of trash bags and a pair of gardening gloves and went out to pick up the trash and trim back the weeds. I couldn't have imagined what happened next if I had been trying to write a primer on grass roots activism.

It was the kids and their curiosity and their boredom. It started with "Whatcha doin' in the lot?" and as I explained and found myself talking about growing flowers instead of trash, it turned into "Can I help? I'm strong, see? I can pick up trash!" By 9 a.m., there were at least ten kids - every one of them under 15 - dragging trash to the front of the lot, filling bags with all the detritus of years of neglect and excitedly calling for me to "come see what I found!! Look! Can we plant this one??" They discovered irises and hydrangea, violets and antique roses - the remains of an old garden gone wild. By noon, the neighborhood adults were wandering by and warning me that I was working for nothing, that the neighborhood teens would tear up any garden I planted.

By 2 p.m., a photographer and reporter for the local paper were interviewing the kids and snapping shots of them muscling "boulders" to the front of the lot to build a border. Somewhere in the course of the afternoon, adults started wandering over - the old curmudgeon up the street showed up with a weed whacker and tersely asked, "Where do you want me to clear?" The old Greek lady with the beautiful garden two blocks away trundled up with a little red wagon full of hostas and started to instruct two of the younger kids in how to plant them. By 7, we had a promise from the city DPW that they'd bring a truck by Monday morning to pick up the pile of trash, and three blooming flower beds shimmering in the twilight.

The teenagers didn't tear up the garden because their little brothers and sisters had made it. And as the flowers and vegetables grew, other gardens started popping up. They weren't much - one or two flats of marigolds next to a cement stoop, a single rose bush planted next to a chain link fence, a couple of plotted plants on a front porch - but before the end of the summer, nearly every house in the neighborhood sported some kind of garden. And I had a new motto - changing the world one garden at a time.

It's already June here in New England, and my garden isn't in yet. It's been a rainy Spring with the usual ups and downs in the temperature, which has made it difficult to find the time to do the things I want to do out in the yard. Add in the wedding planning - my daughter is getting married later this month and I'm making her dress and the wedding favors (of course I wrote about how to make blooming wedding favors), so more of my time is taken up - not that I begrudge a moment of that. Still - it means that my garden is unplanted and a bit overrun with leggy weeds. Which led me this morning to wandering through my favorite garden catalog and wondering which of the flowers and vegetables would be most at home in my front and side yards. And that led me further to wondering if there was a way to figure out which plants would be most beneficial for the environment - i.e. - which would help fight global warming and reduce my carbon footprint the most.

 We hear a lot about how trees help fight global warming by absorbing carbon dioxide in the air and storing it. Trees are natural air purifiers - but each and every bit of living green that you plant makes a difference. Some plants, however, make more of a difference than others. Unfortunately, it's not as simple as making a list of "The Ten Best Plants for a Garden to Fight Global Warming" because it depends greatly on where you're gardening. A simple rule of thumb to follow, though - the less watering and care a plant needs in order to grow in your garden, the better the chance that it will have a higher positive effect on your carbon footprint.

Here are some other things to consider when you plan and plant your garden to make it even more eco-friendly and reduce your carbon footprint.

1. Choose native plants as ornamentals. They'll be more likely to thrive without extra water, fertilizer or special care.
2. Plant vegetables and fruit. Every bit of food that you grow instead of buying reduces the energy burned in getting it to you.
3. Put in a rain barrel or water butt to collect rain water. Use that for watering your plants as much as possible.
4. Compost. It will reduce the amount of trash that your household generates and provide natural, free fertilizer for your plants.
5. Avoid plants that need a lot of watering. If you must have a lawn, plant grass that isn't thirsty.
6. Put in a water feature. Even a bird bath will add moisture to the air and attract insects and birds to your garden.
7. If you decide to add garden ornaments, choose ornaments made of recycled materials. Don't forget "social recycling" for big ticket items like patio furniture. Check out Craigslist and Freecycle.org for items that other people no longer want.
8. Check with your local university or extension service to find out about the best plants and practices to use in your area.
9. Use natural methods of controlling pests and weeds. For instance, plant chives, garlic or onion sets beneath rose bushes. They'll benefit from the shade and naturally repel the beetles and aphids that seem to love roses so much.
10. Learn about square foot gardening to help you pack as much use out of your soil as you can.

Deb Powers writes about coffee and Fair Trade at Coffee Break Today and about feminist and social issues at Not My Mother's Blog.