November 7, 2014
Dot Zanotti Ingels
The average number of severe weather events that occur in a year is proven to be affected by climate change. Climate change has become a controversial and political issue in the United States and elsewhere. Is it part of a natural warming cycle that would be happening anyway? Or is it anthropogenic (human-induced)?
I think we can all agree that our weather at home seems increasingly unpredictable. Some people will argue that these swings are also cyclical and all will be well, but the consensus among scientists knowledgeable in the subject is that increased carbon dioxide levels in the atmosphere are to blame.
We certainly know that we are in a prolonged drought in California. We are increasingly seeing the implications of this drought in our state agriculture, in our open space native plants, grasses and trees, and in our home gardens.
NO REST FOR PLANTS
According to Sustainable Gardening, some plants and trees are not thriving because the winter cooling period is not long enough for them to get the rest they need for optimal production in the warm season.
Longer warm periods can mean more generations of pests each year. The life cycles of insects, including the beneficial ones, may become out of sync with their prey. The already threatened honeybees can be out of sync with the plants they feed on.
Our amazingly resilient native plants are threatened by changes in temperature, rainfall and pests. The stresses they experience reduce their abilities to survive and reproduce. Recent studies have found that our ancient and young redwoods are not drawing water as easily as they do in years with normal amounts of precipitation and abundant fog.
Hotter summers can cause heat stress even to warm-season crops like tomatoes, especially since we are skimping on their water.
According to the National Wildlife Federation, birds are altering their ranges to cope with warming climates. Many bird species have already shifted their ranges north or up mountain slopes. Some local birds may find new species in their neighborhood competing for resources. You may see some new feathered friends in your yard.
Pollination can be affected by early springs if the pollinators are not yet out and about the garden. Unstable spring weather can lead to early blooms and subsequent frost damage.
Some agencies such as the National Oceanic and Atmospheric Administration are updating hardiness zone maps to reflect the new normal in certain areas.
WHAT TO CONSIDER
What does this potential climate change mean for Marin gardens? It is, of course, impossible to say what Mother Nature has in store for us in the years to come. But for right now you might want to:
Tour your garden frequently with a careful eye to notice what is happening. Check on the health of landscape plants and edibles including fruit trees. This has been an especially hard year for some fruit trees such as those infected with blight. Experiment with more diversity in your garden. A garden with a variety of species can look attractive even if some are struggling and provide insects and birds with culinary choices.
Continue the trend of shedding water-thirsty landscape specimens for succulents or perennials from Mediterranean climates that thrive without summer rain. If you are planting long-lived species like trees, consider which species thrive in a warmer, drier climate.
Compost, compost, compost. Adding organic matter makes soil healthier, allows it to hold moisture better and helps to insulate plant roots from temperature extremes. High-quality compost added to the garden allows the soil to absorb carbon dioxide and store it in the ground.
Think sustainability! Plant a food garden. It is fresh and as organic as you want it to be. If you do not have the space or interest in growing your own food, frequent one of our many local farmers markets. You can source more than just fruits and veggies there. Local ranches sell their meats, cheeses, ice creams and more.
Our gardens and local farmers are our first line of defense in times of erratic climate. The future is uncertain, but together we can encourage the health and sustainability of our gardens.