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Why November is a great month to plant a tree in SLO County

Trees offer health benefits to both humans and the planet, and in the Mediterranean climate of the Central Coast, November is a perfect time to plant.
Trees offer health benefits to both humans and the planet, and in the Mediterranean climate of the Central Coast, November is a perfect time to plant.

California celebrates Arbor Day with tree plantings each spring, but as the days grow shorter amid the crunch of fallen leaves underfoot, November offers a better alternative.

Tree experts say it’s not only a good time to plant a tree, it might be the best time.

The Central Coast’s Mediterranean climate offers hot summers and cool, wet winters. Trees that were planted in spring face a dry summer from which some won’t survive. In the southern part of the state, for example, because of something known as infant mortality, the average life of a tree in Los Angeles is seven years, despite the fact that some species can live hundreds of years.

If you want your seedling to have a better shot at surviving that first summer — let alone growing into a mature source of shade, inspiration and beauty — a better idea is to plant it now, at the start of the (hopefully) rainy season.

Fall rains give young trees an edge and help them better take root. They still will need care, nurturing and water — 10-20 gallons a week — when spring transitions to summer and temperatures rise.

An investment in the future

Today, after four years of drought, even mature trees are suffering. Tree roots grow about three feet below ground (they need air as well as water). As lawns were left to die, trees that relied on the regular turf irrigation become stressed and, in some cases, died — collateral drought damage.

But letting trees die is a huge mistake. They are a long-term investment and provide a range of benefits to the entire community.

Trees do so many different things, it’s rather amazing. They clean the air. They cool the air. They clean water before it goes into the drains.

Cindy Blain, executive director of California ReLeaf

The most beautiful neighborhoods in every city are marked by impressive and wonderful treescapes, and that is no accident. People like to be around trees, shop more in downtowns that have green canopies, and are willing to spend money and effort on trees because they make living spaces beautiful, welcoming and more comfortable.

“Trees do so many different things, it’s rather amazing,” said Cindy Blain, executive director of California ReLeaf, a nonprofit organization that works to enhance the state’s urban and community forests. “They clean the air. They cool the air. They clean water before it goes into the drains.”

In addition, trees provide health benefits to people. Studies indicate that they help reduce blood pressure and stress levels.

“Trees provide such a complex symphony of health benefits that it is sometimes hard to isolate the various ways they make us healthier,” she added. “All this is in addition to providing the oxygen necessary for life on this planet — which we take for granted with every breath.”

Growing for the future

Planting a tree in November is paying it forward — for you and those around you.

While we all need to be mindful of our water usage, even in a drought, it’s still important to plant new trees while protecting the mature trees that make up our urban forests.

Lawns can come and go. You can roll out green turf in a few weeks, water it and it will thrive. Trees do not come and go; they are long-term investments that will out-live the people who planted them and be cherished by future generations.

Matt Ritter is a botany professor at Cal Poly and author of “A Californian’s Guide to the Trees among Us.”

Tree tips

The Urban Tree Foundation, funded by Cal Fire, offers detailed instructions on planting, soil modifications, irrigating a tree and tree protection at www.urbantree.org/index.shtml.

How to choose and plant a tree

Decide on a tree

Fruit tree or shade? Evergreen or deciduous? The Urban Forest Ecosystems Institute at Cal Poly has an interactive website to help. Select from a database of 2,000 trees. Review characteristics — from color of bark and blooms, to style of leaves and diseases a species is susceptible to — with links to nurseries that sell the tree. For information, go to https://selectree.calpoly.edu/

The planting process

From “The Tree Care Primer”:

▪  Dig a hole three to five times the diameter of the container, and deep enough to accommodate the roots.

▪  Remove container; separate and spread out the roots in the hole. Make sure the base of the trunk (trunk flare) lies above ground-level. (It’s better to plant a little too high than too low and bury the trunk flare.)

▪  Refill the hole with the same soil that came out of it. (No need to add amendments, since the tree needs to adapt to the soil in its root zone.)

▪  Repack the soil lightly.

▪  Slowly water the tree, thoroughly drenching the soil around the tree to a few feet from the root ball.

▪  Finish by spreading two to four inches of mulch around the root zone, making sure to keep mulch away from the base of the trunk.

▪  Water the tree with about 20 gallons of water per week throughout the first three to four summer dry seasons.