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GOING WILD WITH NATIVES: Start Planning For CNPS Native Plant Sale With Some Keystone Plant Species

By Susan Lewitt, for Let’s Talk Plants! September 2024.



Start Planning for CNPS Native Plant Sale with Some Keystone Plant Species


Only one month to go to get some wonderful, drought tolerant, no fertilizer needed, pollinator attracting, biodiversity supporting, native plants for your landscaping! The bonus? Quite a few of these are keystone species!

“A keystone species is an organism that helps define an entire ecosystem. Without its keystone species, the ecosystem would be dramatically different or cease to exist altogether.” (- Role of Keystone Species in an Ecosystem, National Geographics Education https://education.nationalgeographic.org/resource/role-keystone-species-ecosystem/)

Keystone species exist all over our planet and one example is the Grey Wolf and the Beaver which were reintroduced to Yellowstone National Park allowing many other native species to return and flourish.


Many plants play the role of keystone species. This includes being a part of the places where we humans reside, especially as part of our landscaped yards. For a balanced landscape that reflects a natural ecosystem, keystone species are a must, and there is a wide selection.


How should you plan for adding these keystone species and other lovely natives to your landscaping palate? And where is the best place to start? On October 19, at the California Native Plant Society’s Annual Fall Native Plant Sale there will be many experts to help you with plant buying decisions. (Information to follow at the end of this article.)


Here are a few keystone species by genus and some of the insects that they host.



One keystone genus, the Oaks, Quercus spp., support 275 caterpillar species throughout their California range as an important keystone species and are critical to the natural health of the San Diego community. The Oaks that are indigenous to San Diego include two species of Coast Live Oaks, Quercus agrifolia and Quercus agrifolia var. agrifolia, Scrub Oak, Quercus berberidifolia, Muller Oak, Quercus cornelius-mulleri, Leather Oak, Quercus durata, Valley Oak, Quercus lobata, Desert Oak, Quercus palmeri, and Interior Live Oak, Quercus wislizeni var. frutescens, California Sister (Adelpha californica) is a visitor supported by these oaks.


Prunus species support 262 caterpillar species in California. In San Diego, there are several of this genus, including the Desert Range Almond, Prunus fasciculata, two species of Hollyleaf Cherry, Prunus ilicifolia, and Prunus ilicifolia ssp. Ilicifolia), Catalina Cherry, Prunus ilicifolia ssp. Lyonia, and Western Chokecherry, Prunus virginiana var. demissa. The Brown Elfin (Callophrys augustinus) relies on the Hollyleaf Cherry, Prunus ilicifolia, Manzanita and Ceanothus species. (https://insectic.com/butterfly-species-california/)



Cottonwoods, Populus species, support 230 caterpillar species in California. The Populus species found in San Diego are Fremont Cottonwood, Populus fremontii, Populus fremontii ssp., and Black Cottonwood, Populus trichocarpa. The Semirelict Underwing (Catocala semirelicta) has been seen visiting Cottonwoods.



Big leaf Maple, Acer macrophyllum, and others in the same genus, support 120 caterpillar species in California. In San Diego, you may be lucky enough to see a beautiful Western Tiger Swallowtail, Papilio rutulus, visiting the Big Leaf Maple.



The Rosa genus supports 99 caterpillar species in California. Species for San Diego that are usually found at local nurseries include the Baldhip Rose, Rosa gymnocarpa, and two Woods’ Rose Species, Rosa woodsia, and Rosa woodsii ssp. ultramonta. One of the insects that may be seen with these plants is the strikingly attractive Glover's Silkmoth (Hyalophora gloveri).



Lupinus is an abundant genus with 28 species in the San Diego area. The 128 species in California support 79 caterpillar species. A couple of the 28 that might be available at the sale and nearby nurseries are Silver Lupine, Lupinus albifrons, and Succulent Lupine, Lupinus succulentus. Lupines are usually available as seeds.


The Rubus genus includes the California Blackberry, Rubus ursinus, and supports 96 caterpillar species throughout California. The Blind-eyed Sphinx Moth, Paonias excaecata, depends on the California Blackberry.


Manzanita supports 68 caterpillar species. Thirteen of these Manzanita species may be found throughout San Diego. A couple found at nurseries and the CNPS plant sale are Big Berry Manzanita, Arctostaphylos glauca, Pointleaf Manzanita, Arctostaphylos pungens. Manzanitas flower in clusters and support pollinators such as the Emerald Moth (Nemoria glaucomarginaria).

 


A genus that supports many species is Salix with 328 caterpillar species and 15 bees relying on it in California. Two species found in San Diego are the Arroyo Willow, Salix lasiolepis, Goodding's Black Willow, Salix gooddingii. Weidemeyer's Admiral (Limenitis weidemeyerii) might visit these trees that are abundant throughout California, but they require more water than most natives. They would be ideal for a moist area in your garden. 



The Ericameria genus has 7 indigenous species to San Diego and not only supports 25 butterfly species throughout California, but also 45 bee species. In San Diego there are Cliff Goldenbush, Ericameria cuneata, Rubber Rabbitbrush, Ericameria nauseosa, Palmer's Goldenbush, Ericameria palmeri, Pinebush, Ericameria pinifolia. These are possible host plants for the Northern Checkerspot (Chlosyne palla).


The Encelia genus supports 5 butterfly species, and 29 bee species. Bush Sunflower, Encelia californica, Brittlebush, Encelia farinosa, are some of the plants found in San Diego. The genus Helianthus is relied on by 58 butterfly species and 47 bee species. In San Diego you may find Sunflower, Helianthus annuus, Slender Sunflower, Helianthus gracilentus. The Grindelia genus is host to 19 butterfly species and 38 bee species and in San Diego they rely on the Great Valley Gumweed, Grindelia camporum. The Bordered Patch (Nymphalidae, Chlosyne lacinia) is one possible visitor.


The Phacelia includes 17 local species and supports 23 caterpillar species, plus 32 native bee species. The plants typically found in the San Diego area includes Desertbells, Phacelia campanularia, Caterpillar Phacelia, Phacelia cicutaria, Wild Heliotrope, Phacelia distans, Parry's Phacelia, Phacelia parryi, Branching Phacelia, Phacelia ramosissima, and Lacy Phacelia, Phacelia tanacetifolia. Imagine these beautiful pink, purple and lavender flowers in your garden.



Parry's Phacelia (upper left & middle) shows off its attractive purple flowers. I wonder if Caterpillar Phacelia (upper right & lower left) fools any birds? Wild Heliotrope (lower middle) has a lavender hue and Lacy Phacelia (lower right) is visited by a bumble bee. (Upper left & right, lower left & middle photos courtesy of Calscape, upper middle by Keir Morse, lower right photo by Rasbok [Calscape]).

 

There are many more keystone native plant species in San Diego and you will find a good many of them at the October CNPS Fall Native Plant Sale. These plants and associated moths, butterflies and bees give you just a small glimpse of the complexity of the biodiversity that we call San Diego. There is much more to our ecosystem, from the soil microbiome to the many species that rely on these plants and animals as part of the local ecology.

To help ensure that San Diego continues to be a biodiversity hot spot, come stock up at the October 19, 2024 CNPS Native Plant Sale.


This year’s location will be SIKES ADOBE HISTORIC FARMSTEAD, 12655 Sunset Drive, in Escondido, California 92025.


The hours are from 9 am to 3 pm and there will be a wide variety of native plants, seeds and bulbs available, booths featuring our partnering groups, sustainable goods and much more.

Experts will be glad to assist you with native plant advice and CNPS members will get a discount. For more information, including a list of available native plants and volunteer opportunities please visit https://www.cnpssd.org/fall-plant-sale-2024. The October article of Going Wild with Natives will have more plant sale information.


References and resources:

“Role of Keystone Species in an Ecosystem”, National Geographic Educationhttps://education.nationalgeographic.org/resource/role-keystone-species-ecosystem/


“Mediterranean California - Ecoregion 11, Keystone Native Plants”, Garden for Wildlife by National Wildlife Federation, https://www.nwf.org/-/media/Documents/PDFs/Garden-for-Wildlife/Keystone-Plants/NWF-GFW-keystone-plant-list-ecoregion-11-mediterranean-california.pdf


 

Susan Lewitt is a member of the California Native Plant Society (CNPS), participating in their Native Gardening Committee, and their Conservation Committee.


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