Native Plants

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Tuesday - November 10, 2009

From: San Rafael, CA
Region: California
Topic: Trees
Title: The perfect tree for San Rafael CA
Answered by: Barbara Medford

QUESTION:

Want to plant a tree that is slow growing and has shallow root system that won't lift the concrete, that does not shed, and is green throughout the year.

ANSWER:

Boy, so do we. If you ever find one, will you please share the information with us, because we get a lot of questions like this. We call them "designer plants," where the gardener specifies their requirements and places the order, like having a suit tailored. Unfortunately, Nature is not that civilized. Plants, even those that are evergreen, will shed things. They bloom to make seed so they can reproduce. The blooms fall off, the fruit (which contains the seeds) falls, and leaves die continually, falling off to be replaced by fresh ones. Slow growing is a little easier to come up with, and most trees have root systems of which the majority is in the upper 12" of the soil. That doesn't mean they won't lift concrete, interfere with foundations and discourage growth of other plants beneath them. You must always plan for that tree to get bigger, no matter how slowly, and trying to plant a tree in a confined space or too close to sidewalks and driveways is just to ask for trouble down the line.

All that being said, we will try to recommend some evergreen trees for the San Rafael area. The evergreen part eliminated a lot of lovely trees. The ones we found native to Northern Califonia seem to be mostly firs and pines, which will drop cones and needles, but at least the cones make good Christmas decorations, and the needles smell good. We tried to find a magnolia, one of our favorite evergreen trees, that would grow in California, but no luck. The magnolia requires an acidic soil, and most of western America has pretty alkaline soils. Sorry. Follow each link to the page on that particular plant to find their projected ultimate size, whether they grow quickly or slowly, and what conditions and soils they require.

Evergreen trees for Marin County, CA:

Abies concolor (white fir)

Pinus contorta (lodgepole pine)

Pseudotsuga menziesii (Douglas-fir)

Tsuga mertensiana (mountain hemlock)

Cercocarpus montanus var. glaber (birchleaf mountain mahogany)

Quercus agrifolia (California live oak)