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Blue Elderberry tree once provided needed shade in Garden of Dreams,
CSU Dominguez Hills |
The
past few years have been sobering for anyone concerned with our planet’s future. In
Southern California, the effects of four years drought can be seen in nearly every
garden and wild place. Record-breaking
heat and winds have also plagued us, compounding the effects of the drought. Climate change is happening right now – and
we’d best be planning for more to come.
In
2014, we gave a talk on Climate Change and the Southern California Garden. We
discussed the climate models, their predictions for Southern California and the
implications for local gardens. Two
conclusions are clear: 1) overall temperatures – and the number of high heat
days (> 95° F; 35° C) – will increase in S. California over the next
century; 2) the frequency of extreme precipitation years (both drought and greater than normal precipitation)
are also likely to increase. For more predictions see our 2014 talk: http://www.slideshare.net/cvadheim/climate-change-2014.
Our
gardens must provide more shade in the
future. Hardscape features like
patios, arbors and awnings are one way to create shade. But ‘living shade’ – that provided by trees,
shrubs and strategically placed vines – has additional benefits. Plants cool the surrounding areas by
evaporative cooling; that’s why the shade under trees feels cooler than the shade
under a patio roof. Plants also release
oxygen, clean the air of contaminants and provide habitat for numerous
creatures. If chosen carefully, shade
trees and shrubs provide colorful flowers, edible fruits and a green oasis in
summer.
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| Toyon (Heteromeles arbulifolia) - pruned as tree |
Ideally,
shade-producing plants are long-lived – 50 or more years is ideal. That means that shade trees planted now must be tough enough to thrive in the
climate of 50 years and more in the future.
We’re betting strongly on California natives, including some trees and
shrubs that already grow in the Los Angeles Basin. Locally
native survivors are appropriate for our soils and provide key habitat for
local creatures. So we should use the local natives when appropriate.
But the choice of trees that can survive and thrive into the future is anything but straight forward. To learn more - and for a list of suggested trees and shrubs - see: http://mother-natures-backyard.blogspot.com/2015/09/sustainable-gardening-trees-for.html
