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TREES, PLEASE! Cal-Polytechnic University Urban Tree’s Website

By Robin Y Rivet, for Let's Talk Plants! October 2021.

October is prime tree planting time. Suppose you’d like an evergreen with fragrant, white flowers, adapted to Sunset Zone 23 or 24, and a height range between 30’-50’. How would you choose? The new UFEI website searched and found 47 filtered options.

What is “UFEI”? The acronym stands for ‘Urban Forest Ecosystem Institute’. It is an online resource for western urban trees that includes tree selection assistance, an urban tree identification key, a database of California’s Biggest Trees, an Urban Tree Inventory, and a separate section on Pacific Island species. The site is managed by Cal-Polytechnic State University/San Luis Obispo - which delivers solid academic rigor.

Tree selection alone is a very complex topic. People often assume they want a “small” tree or a “fruit” tree, but there’s so much more to consider. What factors should you investigate when choosing a species?

· In which Sunset Climate Zones are various species considered successful?

· What is the probable mature height and width?

· Are evergreen or deciduous species desirable?

· Do you seek a flower hue or unique fragrance?

· What about foliar variegation, fall colors, or other notable characteristics?

· Can the species tolerate coastal salt spray?

· How much water is needed for optimum growth?

· What soil type or pH are preferred?

· Are there edible fruit, nuts, or other parts to nibble?

· Do you want a California “native” tree?

· Are power line obstructions a consideration?

· How much debris is shed - and when?

· Some species are fast growing, others rather slow…

SelecTree allows you to select filters and hit “SEARCH”. You can also enter scientific or common names to access species information: like “Prunus” or “cherry”, and most have vivid photographs. At first, check 3-4 fields and see what turns up.

Curious to know what tree is growing in your neighborhood with some odd-looking seed pods? The Urban Tree Key now includes over 350 species - typically found in western regions. The dichotomous key is mostly pictorial, and you don’t need a degree in botany to utilize it.

If you’re inherently curious, or truly desire to be part of history, you can also check out the California Big Trees Registry to see their locations and sizes, and consider nominating a magnificent new specimen to be a California Big Tree champion. The largest documented Torrey Pine currently resides in Santa Barbara County, but San Diego County needs more eyes (and hearts) looking out for significant landmark trees here.

The Urban Tree Inventory is an awesome tool for research projects, or just inquisitive minds. It includes over 6.6 million specimens compiled from CA municipal datasets. These are predominantly public land tree inventories - obtained through private contractors. You can query by county, family, genus, species, DBH, and Zip. San Diego County alone cites 658 different species.

UFEI also has information on nursery tree stock, urban wood recycling, and grant opportunities. If you desire a species that isn’t listed for your Sunset Zone, check locally; as weather patterns are changing rapidly. Although UFEI has pretty good content, there’s always flaws. Crape Myrtles not listed as appropriate for our county, but hybrids thrive here in inland valley zones, where they’re well-suited for small parkway sites.

No matter. Please - plant a tree somewhere.


Member Robin Rivet is an ISA Certified Arborist – contact her:


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