Interview with Phil Van Soelen and Sherrie Althouse-CalFlora Nursery
Phil and Sherrie opened Cal Flora in 1981 as a native plant nursery, emphasizing natives, and species and genetic diversity. Awards include 2002 Annual Award from the California Horticultural Society for contributions to California horticulture, and the 1988 Xeriscape Award of Excellence from the Sonoma County Water Agency. Both are past presidents of the Sonoma County Chapter of the California Native Plant Society.
MG: Most gardeners find new types of plants irresistible. And every year, nurseries and catalogs offer a dizzying array of new hybrids plus plants from other regions. Given this trend, I’m curious why you chose to open a nursery devoted to California natives.
Sherrie: Just for the record - we don’t grow strictly natives. We do have some non-natives. I like to try new plants as much as the next person, but I always come back to the natives because they move me the most deeply.
When I moved to California, after growing up in Pennsylvania, I was amazed to learn that most California natives go all summer without water. And I realized I still had lots to learn when I tried to grow a vegetable garden in the middle of a Redwood forest. The garden was a huge failure. Luckily, we had some native plants on the property. I couldn’t help but look around, and see that they were doing fine!
At the same time I was taking a class at the JC about plant adaptations. And I started thinking about all the techniques that natives have evolved to deal with a lack of water: leathery leaves, grey fuzz, summer dormancy, to name a few. As a result, I developed an appreciation for natives’ endless abilities to adapt to a long, dry period. I think that natives are beautiful, but I also deeply admire them.
Phil: My motivation for starting the nursery came from a love of being around natives in the wild. If I didn’t see them in that context, I wouldn’t have the same connection with them. Like many people, I have developed a personal relationship with nature. I’m constantly looking at vignettes and tableaus in nature and thinking – wow - that’s beautiful and so subtle. At the same time, natives fit in with this climate and environment. I find that I want to be surrounded with that kind of beauty.
MG: We hear so much about the importance of diversity. I’m wondering - why consider planting more of whatever already grows here.
Phil: Intuitively, it seems that the more plants we introduce, the more diverse our environment will be. The real diversity lies in the broad palette of native plants, which have evolved to find a niche in this environment. And the more plants that are introduced from other areas, the more the pre-existing balance is affected. With that shift, native plants lose their niches, and consequently, the less diverse our environment becomes.
For example, when feral cat populations are introduced to island habitats, the animal diversity decreases because cats frequently eliminate whole species of native animals which haven’t co-evolved with them. The same thing occurs in our native environment. Many of the vigorous plants that we introduce as ornamentals can adapt to our environment. They become a form of pollution, which is not short-lived, and which undermines diversity. Instead of a rich variety of native plants covering our hillsides, we end up with big swaths of just a few plants such as Eucalyptus and Scotch Broom, both introduced.
Sherrie: The importance of diversity can be seen in the collapse of the European honey bee population. There is good reason to be concerned about that loss. Fortunately, we’ve already got many useful native pollinators. As a result, there’s a growing trend to plant hedgerows around farms because they attract beneficial insects and pollinators.
California has incredible plant diversity compared to other parts of the world, yet we’re losing it so fast. Maybe it wasn’t such a big issue 50 years ago, but now the native places are dwindling. Now we have narrow corridors rather than a vast wilderness. Diversity is something we want to encourage, while we still can.
Lastly, there is so much we don’t understand. We’re losing species right and left, and we don’t even know what we’ve got yet, not to mention the inter-relationships.
MG: Before we talk any further, could you define the term “California native”?
Phil: There are different criteria, but the scientific view is that a California native is a plant that grew here, up until the time Columbus arrived in the Americas. It excludes any plants introduced later on from Europe, Asia or other parts of the world.
MG: And what is an escaped exotic?
Phil: An exotic is a plant that comes from another environment. An escaped exotic is a non-native plant that has gone wild. It is the equivalent of a feral cat. This type of plant affects the environment by becoming established in the native ecosystem.
MG: Getting back to our discussion about diversity, does less plant diversity affect wildlife? If so, how?
Sherrie: As a result of evolution, native fauna (insects and animals) have developed intricate, interdependent relationships that depend on native species. And non-native plants cannot offer what the native fauna needs to survive.
Phil: Perhaps our perspective about insects needs to change. Non-natives used to be encouraged because they were relatively pest-free. But not all insects are the enemy; many insects are beneficial to native plants. Likewise, native plants provide food for the insects. For example, Aristolochia californica (Dutchman’s Pipe) is the larval food for a native butterfly. For butterfly lovers, the caterpillar munching on a native plant isn’t a pest; it is something to value.
MG: Well, a Petunia has all the structures - such as a stamen and pistil - seen in a native Penstemon. So, why is a native Penstemon so important to our native wildlife?
Phil: While native plants are often very beautiful, they are sometimes more subtle than the plants available at a local garden center. They’ve evolved to appeal to their native pollinators, not necessarily to the human shopper. A flower that is big and showy and appealing to a human may not be at all attractive to a native bee or butterfly. As humans, many of us respond to large flowers and bright colors, while the native pollinator may be responding to a plentiful nectar source with a convenient perch or other structure which allow them to be comfortable while feeding.
Many native plants that attract lots of native insects have clusters of tiny individual flowers. The lovely giant buckwheat, Saint Catherine’s Lace, is an excellent example of this type of inflorescence.
MG: There’s been a lot of buzz in recently published books about plant communities. Could you comment about that concept?
Phil: The concept of plant communities is used to understand where native plants originate. Plant communities provide a clue about what conditions a plant may need. However, naming those communities can be arbitrary, depending on how detailed your criteria is. Nature has lots of combinations that don’t always fit into the little categories that humans devise. For example, you can divide Sonoma County into 2 basic areas – dry interior and cooler moist coastal region. On the other hand, you could say that we have 15 or 20 plant communities here, or more.
Sherrie: Identifying plant communities can be used to understand the association of plants that occur in specific ecosystems. The point is to evaluate your garden location and influences – its soil, other plants, wind, rainfall, etc.
Your chance of success will certainly be greater if you work with your existing conditions. For example, if you live in a Redwood forest, you’re going to be more successful if you’re using woodland plants. You can draw from woodland plants from all over the world, but the most successful will definitely be California Native Redwood understory plants.
It is useful to observe plant communities and use that when planning your garden. On the other hand, I don’t think that you need to figure out what used to grow in your environment, and then feel limited to growing only those plants.
MG: It sounds like the old principle of putting the right plant in the right place, also applies to natives.
Sherrie: Definitely! I’ve noticed that when Phil places water-loving plants, he always checks the terrain carefully. Invariably, he finds a spot at the base of a hill, or a place where the water collects, and that’s where he puts the water loving plants. Use those same principles of plant communities when you evaluate conditions in your yard.
The notion of understanding a plant community can also be very handy when dealing with microenvironments. For example, an artificial mound can mimic chaparral conditions. If you’ve got lean soil and a south facing slope and you don’t water it much, maybe chaparral plants are just what you need, even though there never was any chaparral for miles around.
Phil: Natives really have the upper hand in the extreme environments of a Redwood forest or the coast bluffs because they’ve co-evolved with those environments. The coast bluffs have blasting winds and sandy soils. And, in Redwood forests, darkness prevails, with fibrous roots grabbing all the water and nutrients, while debris is raining down. The non-natives are not very happy with either those conditions. Instead, the plants that have spent thousands of years evolving under those conditions will be most successful.
Sherrie: If you’re in a coastal bluff or a Redwood forest, or any intact plant community – even in the middle of Oak woodland - it may be hard to garden. The easiest way is take a tip from nature and follow that.
MG: We hear a lot about our area having a Mediterranean climate. How does that relate to California natives?
Sherri: A Mediterranean climate characteristically has wet winters and long, dry summers. In most locations, the warm season is also the wet season. Here, our rainfall pattern is the opposite.
Phil: Mediterranean plants are found in a very small amount of the world’s land mass - only 1-2%.
MG: Are there microclimates within that restricted environment?
Sherrie: Even within the Mediterranean climate, there is incredible diversity. Sonoma County has plants that have adapted to lots of factors – exposure, wind, elevation, moisture, and soil types. For example, we even have riparian areas, where there is year round water. That’s where the flora (plants) looks like the East Coast.
MG: Those riparian areas are pretty limited.
Sherrie: Yes, and they are disappearing!
MG: I understand that riparian areas are more vulnerable to escaped exotics.
Phil: They are. Plus, those waterways are invariably linked together. When something escapes in the upland, the seeds can travel all the way to the mouth of the water.
In contrast, hot dry sites tend to be pockmarked here and so they are less vulnerable to escaped exotics.
MG: Are there specific ways that you recommend incorporating California natives into our home gardens?
Sherrie: I think it is important to place plants with similar requirements together. If you have a sunny dry area, use plants that thrive under those conditions.
Phil: The same conditions in which lavender and Rosemary thrive, would also be suitable for Ceanothus, Manzanita and sages. Those natives do not like heavily watered or fertilized sites. They need environments that have excellent drainage, less water and good sun exposure.
MG: Do California natives require specific conditions?
Phil: Definitely! Sometimes people assume that they can plant California natives and then just walk away. Well, natives are well-adapted to a certain set of requirements that existed in pre-Columbian times. Now we have new factors, such as escaped exotics, plus changes made to the land through grading and compacting.
From a native’s perspective, the typical suburban garden is over-watered and over-fertilized, and it has badly compacted soil. Native plants play by different rules! For example, native seeds have adapted to germinate in cold, wet conditions and won’t germinate under warm, greenhouse conditions.
Sherrie: Even professional landscapers, who like to use natives, have difficulty accepting the idea of watering deeply and occasionally, compared to regular irrigation. On the other extreme, they often consign natives to sites with poor, compacted soil and then provide no maintenance. Then, people assume that natives can only look dry and unmaintained.
When native plants don’t thrive in a garden, there is nothing wrong with the plants. Instead, the difficulty lies with management skills (i.e. the gardener!)
With a little TLC and water, natives can be very attractive. At the same time, we need to learn to look beyond our culturally-biased idea, which equates only lush, super-green and irrigated landscape with beauty.
MG: And, managing our water supply is certainly one motivation for incorporating more native plants.
Phil: I agree. As a culture, we come from a tradition using heavy irrigation and fertilizing. Our water bills reflect the habit of relying on irrigation systems, instead of planting at the appropriate time of the year. Our culture is at odds with the needs of the planet! If we really understood and were well-adapted to the climate, gardening with natives would be the easiest thing in the world.
It is possible to garden without using copious amounts of water. The properly placed native can go six months without irrigation. That doesn’t mean that all natives are drought-tolerant. If a riparian plant is properly placed in a naturally moist area, or a drought plant is placed in a naturally dry area, there is no reason why those plants can’t go for six months without irrigation. They do it all the time in nature. With the right plant in the right place, you don’t need to irrigate.
But a little bit of irrigation will make natives a little bit lusher and a lot happier in most cases. They bloom more freely, look perkier. While exotics struggle with a small amount of water, natives look their best.
Sherrie: I like the look of nature at this time of year (the fall). It may take an adjustment of our perspective.
Phil: Judith Larner talks about learning to love brown. I’m from Washington and it took me a while to get used to the Mediterranean climate and appreciate it. It is really hard for people, who love emerald green, to suddenly learn to love brown. There’s a wide range of colors between emerald green and brown, most of which can be found in native plants.
MG: Have you seen CA natives used effectively in formal gardens? Or, are they more appropriate for casual gardens?
Phil: The Mediterranean cultures created their formal gardens out of native Mediterranean plants. California plants can be used in the same way - that includes rigid geometry, clipping and bi-lateral symmetry.
But, most people fall in love with natives when they’re seen in a natural setting. Those people usually end up with gardens having naturalistic themes.
MG: Let’s talk about cultural requirements. Do you generally recommend amending the soil before planting CA natives?
Phil: Frequently, there is no need to amend the soil. Many natives don’t need that extra fertility. In fact, nitrogen stimulates the escaped exotic weeds, such as the annual grasses.
However, often the soil is compacted and needs to be loosened up. Get rid of the surface weeds. Don’t amend unless there is some specific need. For example, woodland plants are the most likely to benefit from a little extra fertility. But many of the natives are adapted to our native soils.
When I plant, I dig in a little broken down mulch, but I don’t use conventional amendments or compost, unless the plant needs moisture or likes heavy soil. If anything, I sometimes use phosphate rock dust to add Phosphorus or Potassium.
Sherrie: If people want to invest in their soil, then we recommend mulch. Common garden tolerant Manzanitas like ‘Emerald Carpet’ and ‘Howard McMinn’ benefit from bark mulch. It prevents dirt, which can cause stem and leaf diseases, from splashing up onto the foliage.
However, there are certain chaparral species of Manzanitas, that don’t benefit from bark. These plants have evolved in lean, well drained soils. Mulching these species, with clean, crushed granite or other rock mulches, often works best.
In general, I feed my garden by using a wood chip mulch, which will break down over time, slowly. Most amendments cause plants to grow in a big jolt. Their excessive growth makes them susceptible to insects and disease.
The idea is to be in sync with our environment - both with the water we use and the materials we put on the landscape. Use nature as a guide. In nature, leaves fall. They start breaking down and add soil fertility over time. Slow long term growth is, by far, most beneficial.
Of course, there are sites where you’re left with totally dead soil or it is compacted like crazy. Natives can’t be expected to grow under those situations without some help.
MG: When is the best time to plant California natives?
Phil: As soon as the days get shorter, the weather gets cooler and the light intensity is reduced – even before the rains start – is the ideal time. I dig a hole, fill it with water and let it drain – sometimes twice. While the plant is still in the pot, I’ll plunge it into a bucket of water so there is plenty of moisture. At this time of year, it is easy to keep up the moisture level until the rains come.
MG: I’ve often heard people state that California natives are deerproof.
Sherrie: A lot of people think that. Deer evolved with the native flora so they do eat it. Luckily, there are natives which they don’t eat. But in general, there are lots they love.
MG: What plants do you recommend to people who need their gardens to be deerproof?
Sherrie: There is a core group of plants that we can recommend. Fortunately, deer don’t like grasses and aromatic plants. Iris are good, too. The list changes over time. Because we sell to the entire Bay area, we get mixed reports. What deer eat in one area, they leave alone in another. Their tastes change as food sources dry up, too.
People devise different strategies to deal with California natives that deer eat, like Fremontodendron (Flannel Bush) and Ceanothus, by planting deerproof plants around their base. Or, they protect them with fencing until they get above the browsing height. Sprays work, too, although you have to re-apply them periodically.
We still advise people that even deer resistant plants should be protected after being purchased from a nursery. Aromatic oils, that discourage deer, are not yet concentrated in a young plant.
And deer are curious creatures. I frequently have heard from customers that deer will pull a plant out of the ground, taste it, and then drop it because they don’t like it!
MG: I live in a rural area with many deer. After some heartbreaking losses, I’ve discovered that I lose fewer plants to deer if I plant after we’ve had a few solid rains. Until then, the deer are very hungry and thirsty. Once there is enough fresh foliage and grass, the deer are less interested in my young plants. If I don’t wait, I’m simply feeding the deer!
Phil: Deer can smell water very well. If the ground is dry and you’ve just planted a well watered plant, they’ll home right in on it. Sometimes they’ll eat a plant for the water it provides. If you wait to plant when everything is lusher and wetter, a new plant won’t stand out as much.
MG: I’m hearing more and more use of the term “garden-worthy natives” which is applied to natives that work well in conventional garden settings.
Phil: Sometimes a species - desirable in all other respects - doesn’t grow or thrive. Through trial and error, Horticulturalists will find individuals of that species that are more amenable to cultivation. As a result, we’ll probably see an expanding number of such “tame” native cultivars available over time.
Sherrie: There is an interesting trend developing about eating regional food. To me, native plants fit into that perspective. I look to the landscape to get a sense of place. I prefer the look that spells where I am, in contrast to the homogenous look of the suburbs, which look the same throughout the country.
California natives have a subtle, quiet beauty. Consider a Manzanita, with its picturesque, maroon bark and it’s tough, leather leaves and urn-shaped flowers. Most of us have come from other climates and we bring our idea of beauty with us. But we are in California now, where water is a precious resource. And instead of looking it as a shortcoming and trying re-create where we came from, we can re-shape our thinking and embrace our climate.
We can have gorgeous gardens with California natives and Mediterranean plants. We have so much to work with. It is not a limitation.
Phil: Pacific Horticulture is fine example of a magazine which provides gardens which are appropriate for this area. If we are constantly bombarded with the lush, green look of the East Coast and England, and then told it is beautiful, it is plant porn in a way. It is easy to lose sight of what we have here.
It is time to have more magazines that portray beautiful Mediterranean gardens.
MG: Are there any closing comments you’d like to make?
Sherrie: I find gardening with natives fascinating because there are endless relationships between the plants, animals and insects. I’ll never understand it all. It is a story that continues to be revealed if I’m willing to look and am sharp enough to figure it out.
There are a wide variety of natives from many different environments. So many natives are very straightforward and easy to grow. If given the right conditions - and their requirements are few - natives are easy to grow.
Phil: Natives are so well adapted to our area. We have a cold snap, and what does well in our gardens? The natives often do. The frou-frou plants suffer from temperature extremes and drought, yet the natives are chugging along because they’ve had years to adapt to this environment.
We are inspired when we see what nature does with natives. For us, they offer a never ending enjoyment when gardening with them. How could they not? They’re gorgeous; they’re never boring. I can’t help it. Over time, I find myself falling more and more in love with natives.
- Seed Hunt
- Larners Seeds
- Buckeye Nursery, Petaluma
- Cal Flora (California Flora Nursery), Fulton
- Hummingbird Nursery, Sebastopol
- Mostly Natives, Tomales
- North Coast Native Nursery, Petaluma
- Plants and Landscapes for Summer-Dry Climates of the San Francisco Bay Region by East Bay Municipal Utility District
- California Native Plants for the Garden by Carol Bornstein, David Fross & Bart O’Brien
- Designing California Native Gardens by Glenn Keator & Alrie Middlebrook
- Native Treasures by M. Nevin Smith
How to help CA natives flourish
Join CA Native Plant Society
Don’t plant invasive exotics
Let a little of your property grow wild by planting and getting to know some natives in your garden.
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