By David Layland, U. C. Master Gardener of Napa County
Climate change, also called global warming, has been in the news lately because of the devastating wildfires in Northern and Southern California. Climate change refers to the rise in average surface temperatures and is due primarily to the use of fossil fuels which releases carbon dioxide and other greenhouse gases into the air.
The gases trap heat within the atmosphere, which can have a range of effects on the environment including rising sea levels, severe weather events, and droughts that render landscapes more susceptible to wildfires.
There are two ways to mitigate the environmental damage done by fossil fuels. The most common way is to reduce the use of fossil fuels—by driving a hybrid or electric car, for example, or using solar or wind power. The second way, carbon sequestration, involves pulling carbon out of the air and storing it in the ground.
I don't drive a hybrid or electric car but I do have solar power. It provides 90 percent of my electricity at home so I've done something toward lowering emissions.
Carbon sequestration is new to me. In researching what I could do to help pull carbon out of the air, I discovered that I'm already using several carbon-sequestration practices in my garden. To some extent, these practices are what organic gardeners have been doing for a long time.
Make compost: One of the primary differences between organic and conventional gardening can be boiled down to a simple change in perspective: Instead of worrying about feeding the plants, we should worry first about feeding the soil. Take care of the soil and the plants will take care of themselves.
By composting all of our food scraps and garden waste, we aren't just providing valuable nutrients for plants. We are providing food for a huge ecosystem of bacteria, fungi and insects, all of which help to absorb carbon from the environment and keep it locked up in the soil. You can add cardboard and other paper-based waste to your compost, too. High-fiber composting works, and it's another way to lock up some CO2.
Don't dig: Many old-school gardeners may scoff at the idea of no-dig gardening, but there are good reasons to abandon the rototiller and dig only when necessary. No-dig gardening could have a significant impact on preserving soil carbon.
By slowing down the rate of decomposition in the soil, you help increase soil carbon and save yourself some labor. More than 15 years ago I purchased a rototiller because I thought I “needed” one for my garden and vineyard. I used it for a few years, until I realized I didn't need it. It sat under a tarp for a few more years until I found a new home for it.
That was an expensive lesson. Not using a gas-powered rototiller also means you are not using fossil fuels and are not spewing pollutants into the atmosphere. And you're not killing the hard-working earthworms that are improving your soil health.
When you refrain from tilling, you avoid exposing the soil to excess oxygen and sunlight. You can achieve the same thing by mulching, but an even better way is to plant cover crops, or so-called green manures, which can later be hoed in or mowed down. Doing so will add carbon to the soil while helping the root system keep soil in place. Cover crops also provide a habitat for soil life when you don't have edible crops.
Lose the lawn: This recommendation was easy for me. Before my wife and I moved to Napa, we had a lawn that was more than an acre and, of course, we had a riding lawnmower. After four years of mowing this lawn I never wanted to have another one.
The standard lawn requires a considerable amount of costly maintenance, water and chemicals if you want that green carpet to look perfect. There are many environmentally-friendly alternatives to a lawn. In Napa, I opted for decomposed granite. There's no maintenance and the permeable surface allows water to reach the soil. I added a few drought-tolerant plants for color and trees to shade the house. And I'm saving fossil fuels by not using a gas-powered lawnmower.
Grow lots of stuff (except a lawn): To store the maximum carbon, always keep the soil surface covered with growing things such as trees, turf, vegetables, flowers and cover crops. The more variety, the better. Grow plants with deep, extensive root systems and coarse, woody roots; shallow, fine roots decompose too easily. If I had it to do over again, I might not use as much decomposed granite as I did. At the time, I was focused on lawn alternatives, not on carbon sequestration.
So there you have some tools for carbon sequestration at home. Now go out there and do your part to fight climate change.
Workshop: U. C. Master Gardeners of Napa County will host a workshop on “Rose Pruning” on Saturday, January 13, from 10 a.m. to noon, at University of California Cooperative Extension, 1710 Soscol Avenue, Napa. Why do we prune roses? Is winter the only time to do it? What will happen if we don't? Should hybrid teas be pruned differently from floribundas? Join the Master Gardener Rose Team at this popular forum where resident experts will answer your questions about basic rose pruning fundamentals with research-based information. Topics include rose types, how and when to prune, what tools to use and how to care for them, safety and sanitation. No doubt each Master Gardener will have some suggestions for new plantings, too. Online registration (credit card only);Mail-in/Walk-in registration(check only or drop off cash payment).
Master Gardeners are volunteers who help the University of California reach the gardening public with home gardening information. U. C. Master Gardeners of Napa County ( http://ucanr.edu/ucmgnapa/) are available to answer gardening questions in person or by phone, Monday, Wednesday and Friday, 9 a.m. to Noon, at the U. C. Cooperative Extension office, 1710 Soscol Avenue, Suite 4, Napa, 707-253-4143, or from outside City of Napa toll-free at 877-279-3065. Or e-mail your garden questions by following the guidelines on our web site. Click on Napa, then on Have Garden Questions? Find us on Facebook under UC Master Gardeners of Napa County.
By Daniel McLoughlin, U. C. Master Gardener of Napa County
Most Napa Valley gardeners have long embraced the idea that planting native species is the way to go. These locally evolved species tend to be more acclimated to our long, dry summers and less thirsty as a result.
But there is growing evidence that native plants do far more than just save water. A study by scientists at the University of Delaware and the Smithsonian Migratory Bird Center, recently published in the journal Biological Conservation, underscores another way that native plants can support local ecosystems in urban and suburban settings.
The study was conducted over a four-year span. The observation team identified where breeding birds foraged for food in the yards of 203 homes in the Washington, D.C., metropolitan area. They documented which plants provided the most bird food, such as insects and caterpillars.
Among the findings were that native plants provided more caterpillars than non-native plants, that the birds preferred foraging in native plants and were more likely to breed in sites with native plants.
While these findings may be limited to the specific parameters of this study, the idea that the natural world is deeply interconnected comes as no surprise. We now understand that most insect species evolved over time with a specific plant species or group of plants.The insects adapted to the chemical defenses of its host plants.
Often these adaptations are very precise. Caterpillars, an important food source for birds, tend to be picky about what they eat. For instance, the Monarch butterfly larva must have milkweed (Asclepias fascicularis) to survive. Most insects and animals avoid milkweed because of the toxins and latex it secretes, but the Monarch has adapted to it. In fact, the Monarch will only lay its eggs on milkweed. Without milkweed along its migratory path, the Monarch cannot reproduce and the creatures that feed on Monarch caterpillars must look elsewhere for a meal.
Last year, the Audubon Society launched the Plants for Birds program, which encourages and provides resources for people to support birds by planting native species (http://www.audubon.org/plantsforbirds). The site also provides a database by zip code that helps to identify local native plants and the types of birds they tend to attract (https://www.audubon.org/native-plants).
According to the Audubon Society, the human-dominated landscape “no longer supports functioning ecosystems, and the remaining isolated natural areas are not large enough to support wildlife.” This situation is the result not just of urbanization and expanded agricultural production, but also of our desire for manicured lawns and exotic ornamental plants. Research by the entomologist Doug Tallamy has shown that native oak trees support over 500 species of caterpillars, whereas the gingko, the commonly planted and beautiful landscape tree from Asia, hosts only five species of caterpillars.
ReScape California, also known as the Bay-Friendly Landscaping & Gardening Coalition, is a resource for those who want to learn more about incorporating biodiversity into their landscape. Among its guiding principles are water and energy conservation, improving the “soil food web” and reducing the landscaping impact on landfill.
In this organization's view, maintaining a Bay-friendly landscape means recognizing that “biodiversity is crucial to the health of natural ecosystems and that by using native plants and increasing the diversity of plant palettes, our built landscape can provide food, water and shelter for birds, butterflies, beneficial insects and other creatures.”
According to U.S. Census data, there were nearly 66,000 people living in Napa County in 1960. By 2010 the county's population had more than doubled. That increase mirrored the growth of the Bay Area as a whole, which almost doubled in population in those five decades. Our ancestors needed space to live, just as we do, and so will those who come after us.
I fuss over my lilacs because they demand it and because I love them, but the fact is, they contribute almost nothing to everything else that lives in my yard, or might want to live here. Nothing ever eats them. The same goes for the Australian tea tree, even though it's never thirsty.
I'm not going to pull these plants out, not yet anyway, but the next time I have the chance, I'm going to think about the birds and the bees and the caterpillars. After all, I'm not the only one who lives here.
Workshop: U. C. Master Gardeners of Napa County will host a workshop on “Rose Pruning” on Saturday, January 13, from 10 a.m. to noon, at University of California Cooperative Extension, 1710 Soscol Avenue, Napa. Why do we prune roses? Is winter the only time to do it? What will happen if we don't? Should hybrid teas be pruned differently from floribundas? Join the Master Gardener Rose Team at this popular forum where resident experts will answer your questions about basic rose pruning fundamentals with research-based information. Topics include rose types, how and when to prune, what tools to use and how to care for them, safety and sanitation. No doubt each Master Gardener will have some suggestions for new plantings, too. Online registration (credit card only);Mail-in/Walk-in registration(check only or drop off cash payment).
Master Gardeners are volunteers who help the University of California reach the gardening public with home gardening information. U. C. Master Gardeners of Napa County ( http://ucanr.edu/ucmgnapa/) are available to answer gardening questions in person or by phone, Monday, Wednesday and Friday, 9 a.m. to Noon, at the U. C. Cooperative Extension office, 1710 Soscol Avenue, Suite 4, Napa, 707-253-4143, or from outside City of Napa toll-free at 877-279-3065. Or e-mail your garden questions by following the guidelines on our web site. Click on Napa, then on Have Garden Questions? Find us on Facebook under UC Master Gardeners of Napa County.
