FALL IS THE TIME TO PLANT NATIVES!
Native plants placed in your garden now will thrive and send down roots with the fall and winter rains (or the supplemental water if there is insufficient rain). Plants from local natural areas enhance the habitat value of your garden and attract a wider variety of birds and beneficial insects, including some of our lovely local butterflies.
As with other garden plants, the key to success is grouping the plantings by preferences for water regime, soil and exposure to sun. You can search out the needs of plants at calscape.org, a very flexible and informative website designed by the California Native Plant Society. Some of the most popular and easiest to grow natives are those that can be mixed in gardens with common low water use landscape plants. These are often the same plants that dwell along canyons and stream sides where water is held deep in the ground and there is some protection from the harshest dry summers. Some of these such as Toyon (Heteromeles arbutifolia), Sugarbush (Rhus ovata) and some of the sages have been used horticulturally for decades. Some Channel islands shrubs do well grouped here also, such as the Island Snapdragon (Gambelia speciosa) an attractive low growing mound of lush green color and cheery red tubular flowers or the Catalina Current (Ribes viburnifolium) one of the most civilized appearing natives. Many herbaceous flowering plants such as Lupine, Monkeyflower, the ground-hugging lavender Seaside Daisy, Coral Bells, Blue-eyed Grass, Peninsular Onion, the showy Clarkias and the ever favored California Poppy will combine well here. For both flowers and a mellow minty aroma, Monardella is a winning herbaceous plant.
To create a garden with real California flavor, go a little dryer. You will be rewarded with rich golds, rusts and grays and the aroma of the chaparral. Favored for flower color in dryer areas would be the California Bush Sunflower (Encelia californica) or low growing Epilobium, sometimes called California Fuschia because of its abundant red flowers. Many Buckwheat species add interest. The Giant Buckwheat has large flower umbels that are showy and curious. Smaller buckwheats add unique color such as the sulfur flowers of Conejo Buckwheat and rose to rust flowers of our local Buckwheat Eriogonum faciculatum.
For grey foliage from white gray to dark gray green, look to the Sages. There are several that form low mats such as Terra Seca and Pt. Sal. The local Purple Sage and its San Diegan cousin Cleveland Sage are known for their wonderful fragrance that will fill the garden, especially on spring and summer mornings and evenings.
The Manzanitas have twisted mahogany branches and often gray green or leaves tinged with reds or yellows, charming bunches of small urn shaped flowers and showy berries. These also come in low growing mat, or large or small shrub forms.
All plants need watering until the roots become established and natives are no exception. Since natives are adapted to a rainless summer, it works best to get some of those roots established during the rainy season. Plants that are used to moist canyons will do better with summer watering if it is applied outside the “drip line” but even plants for dryer areas will need a few supplemental waterings through the first summer or two. If you keep in mind what a good rain year is like in California and where the plant is naturally found, you will know what kind of watering the plant needs once established.
Many of these plants will be available at the California Native Plant Society Spring and Fall Plant Sales.
WHAT ON EARTH TO PLANT?
Governments and communities are grappling with the question of what to plant in this era of climate change. Many large tree planting efforts have been publicized from around the globe. Most of these efforts have been rooted in the ecological knowledge of the local area, with the understanding that random tree planting could cause more harm than good. The superior ability of meadows, grasslands, and other established habitats to sequester carbon has been widely publicized. In making local decisions on what to plant, it is useful to understand the complex of influences that drive appropriate solutions.
Plants, animals, and microorganisms have co-evolved for millions of years and their relationships are complex and specific. Many insects have a close relationship with a small number of plant species or genera that grow in a restricted geographical area. Many caterpillars associate only with plants from a specific genus or two or sometimes just a single species of plant. Studies show that locally native plants can harbor from 5 to 100 times the insect population of non-natives.
Most birds (96% of the terrestrial bird species in North America according to Dickenson 1999, per Tallamy) need a tremendous number of insects and spiders, preferably caterpillars, to support their baby birds. Even seed eating birds require softer food for their young. Without locally native plants (anywhere in the world) birds can only find inferior or insufficient food and populations suffer[i].
Many native plants have developed intricate relationships with soil microorganisms. It has been shown that carbon sequestration is actually accomplished more by the soil microorganisms than the plants, themselves. Many microorganisms are also specific to certain plants and a healthy and diverse intact native area is one of the best carbon sequestration sinks on the planet. Forests, shrub lands, and meadows all have value in their native locations. The restoration and conservation of all types of natural areas should be a priority in the fight against climate change.
Scientists, including those with the California Native Plant Society, are studying the effects of climate change with a target of identifying refugia that might be available to plants being forced out of their traditional habitat.
Refugia are areas where plants may be able to migrate, along with a good component of their associated species. Geographic proximity facilitates this community migration which might be allowed to happen if we can preserve the opportunity in a knowledgeable, integrated way. We can ensure that plant species and/or communities will be able to migrate as environmental conditions change if we plan for a connected network of reserves and/or refugia.
Most natives have considerably diverse genetics and when faced with changes in weather, it can be assumed that a certain percentage will likely be able to adapt, at least to certain point. At this point, the future of our ecology and the climate is, of course, uncertain, but it is of value to preserve what is possible of the complex and dynamic multidimensional tapestry of nature. Although novel conservation measures might be appropriate if conditions become more extreme, allowing nature to take its own course has a high likelihood of being more successful and preferable under current conditions. Such decisions are best made with the best science available.
The idea that non-natives should be considered instead of natives in natural or sensitive interface landscapes lacks ecological validity. Non-natives would lack the insect and other animal species they were associated with in their native habitat, as well as important microorganisms, and would likely not integrate with the species in their new location in a robust way. The idea that invasive exotics, specifically, have general value is not only without merit but carries the danger that these plants would swamp natives already stressed by the attempt to adjust to the climatic changes.
The term ‘invasive’ has a meaning in ecological studies. Planting a non-invasive, non-native plant in an urban/nature interface area, while not environmentally ideal, may not be of great concern but planting an invasive is. An invasive will propagate itself and spread into the natural habitat, competing for resources with natives, resulting in a number of negative impacts. Without their natural predators (insects, birds, and other animals) they are at an advantage over natives and may spread over large areas, eliminating the availability of space in areas that had been occupied by native plants. In doing so, they deprive the associated plants and animals of the habitat they require. Insects and therefore birds, do not have food, and the food chain falls apart. There is sometimes not even nesting or shelter support, as we see with Arundo in our local streams. Some invasive species, such as annual grasses, increase the risk of wildfires; some guzzle large quantities of water. Invasive plants will also spread to the urban and rural landscape and agricultural areas. Weed control is difficult and expensive. In a quality natural area, the proliferation of exotic species is a real loss and with a stressed area, it can lead to greater degradation. There is no substitute for co-evolved integrity. Natures ability to self-heal may be amazing but if some threads of the tapestry are missing or weakened, the possibilities are limited. Degraded natural areas may be more prone to repeated burning, and chaparral may convert to non-native grassland that is then deemed less suitable for preservation, resulting in an unplanned total loss of complex ecological value of intact natural areas. Invasive exotic plant species are the second greatest threat to biodiversity, second only to development and other human caused habitat destruction
Some have hailed the so called ‘successes’ of invasive plants, claiming they are ‘better adapted’, but what is success for one species is not success for an ecological system. If the invasive non-native supports, for example, an appealing species of bird, it is still not a measure of success for the ecological system. Each situation needs to be studied before taking action and great caution should be exercised in introducing non-natives because, as we have seen, eradication of the species, once introduced, is usually exceedingly difficult.
Still others call for sympathy with ‘immigrant’ plant species. It is important to realize that humans evolved as a nomadic species, spreading throughout the globe and adapting to every climate, habitat and available food. They hunted and brought to extinction many large mammals throughout the world. (Chapter 4, Sapiens : A Brief History of Humankind by Yuval Noah Harari ) They domesticated plants and animals (including bees) and brought them along (and a few pests followed as well). Most domesticated species were kept under control but a few have been invasive and some were accidentally brought along with little awareness of their impact . . . and why should early man be concerned when the world was so large and undeveloped? Man did not evolve with roots in the ground, did not develop symbiotic relationships with specific local soil organisms nor complex relationships with local insects, at least not to the degree that plants did. To confuse the plight of humans currently fleeing their homelands with the value of plants that have been distributed by careless humans like litter, is a grave error in logic.
Humans use a wide array of plants horticulturally, which are widely appreciated for their beauty and interest, or agricultural and consumption value, but one should not be under the illusion that these provide the same ecological benefits as appropriately placed local natives.
Without a doubt, domesticated plants and animals (including bees) are useful to us but even domestic agriculture is more sustainable when natural habitats are nearby, which provide vital ecosystem services such as pollinator diversity. When one sees cultivated plants plagued by insects, it is good to remember that 98% of insect species are beneficial. If a full complex of species is not present, opportunistic pest species are more successful. A native landscape may easily have 100 times the insect life, and it is balanced, so there is less evidence of insect damage to plants, generally. Domesticated plants are useful to us for food, products, and beauty. If grown in a healthy way, they likely support some soil mycorrhizae that sequester carbon and carry out other biotic functions that are environmentally valuable (certainly non-native plants are more valuable than the gravel or cement sometimes used in urban and rural landscapes).
Native plants and ornamental or agricultural plants actually work very well together. There are about 1,600 species of native bees in California and they are generally much more efficient pollinators than honey bees (though they do not produce honey) (http://news.cornell.edu/stories/2011/10/native-bees-are-better-pollinators-honeybees) and they need their specific native plant hosts to prosper. A native Mason bee in an apple orchard is 150 times more effective than a honey bee and will improve the honey bees’ effectiveness by encouraging the honey bees to move around the orchard instead of their tendency to just follow the rows.
Natives in agricultural hedgerows and in residential and commercial gardens are of significant benefit in that they attract beneficial insects that help pollinate and consume pest insects as well as provide an extension of habitat for native birds, butterflies and other small animals.
But what about fire? Our local native plants have evolved with fire. Some have mechanisms that either keep them from burning, or provide for rapid regrowth. Some have seeds that wait in the soil for germination to be activated by fire. The speedy recovery of native plants from fire quickly reestablishes habitat, providing food and shelter to local wildlife.
This is one of the reasons natives are desirable in fire prone areas. As with non-natives, native species can be explosively flammable, but this is rare. All plants burn, however, so the Santa Barbara County Fire Department and the Los Angeles County Fire Department both have lists of plants that are recommended for high fire risk areas and both lists contain natives (though this is an area that is not well researched and there are differing opinions). Bert Wilson of Las Pilitas Nursery did some interesting leaf burn tests. The results can be found here: https://www.laspilitas.com/classes/fire_burn_times.html?fbclid=IwAR3d66_SuzI5qwZw2AutKKDoXiESoIme3k8gPwCZIlPfqtzI9KeFdoXagLc&utm_source=pocket_mylist
Growth habit is more important than whether or not a plant is native when it comes to fire safety. Low growing plants paired with trees (particularly oaks) that are pruned to avoid a ‘fire ladder’ or ‘fuel ladder’ is key, along with removing deadwood.
Plants are the basis of the ecosystem (or at least, the one factor we can, as humans, most easily control or protect). California is one of the most botanically diverse areas of the world. As we are presented with the sixth mass extinction of species on earth, it behooves us to protect the rich diversity we are fortunate to share from this land and remember that keeping these systems intact is one of our most efficient and effective ways to sequester atmospheric carbon. We have the opportunity to be stewards of the rich natural treasure, a complex living tapestry, which has evolved over millions of years. May we protect and pass this on to future generations.
Patt McDaniel is a business owner, horticulturalist, artist, and nature writer and 35 year active volunteer with the California Native Plant Society, currently the Horticulture Chair of the Channel Islands Chapter and Ventura County resident since 1956.
[i] (Doug Tallamy, entomologist https://canr.udel.edu/faculty/tallamy-doug/ has published studies, and the book: Bringing Nature Home )