Rush

91204Not to be confused with the Canadian rock band from the 1970s, this rush, Juncus patens, is native to riparian areas between western Washington and San Diego County. It is also known as the common rush because it is, obviously, the most common species of the genus on the West Coast. It is only occasionally planted intentionally, but more often sneaks into well irrigated landscapes.

Those planted intentionally are mostly cultivars with slightly bluish or grayish foliage, such as ‘Elk Blue’, ‘Occidental Blue’ and ‘Carmen’s Grey’. Those in the wild, or that sneak into landscapes from the wild, are dark green like avocado skin. The upright foliage is really very slender stems that look more like leaves than the vestigial leaves do. It forms dense clumps about one to three feet tall.

Although it is a riparian plant that survives soil saturation and inadequate drainage through winter, rush can survive as soil drains and dries somewhat through summer. It prefers somewhat regular watering in landscapes and home gardens. If cut back to the ground at the end of winter, and perhaps divided, fresh new growth regenerates through spring. Growth is sparse and floppy in shade.

Buckeye

P91109KCalifornia flora is remarkable. It all does what it must to live comfortably in every ecosystem, climate and geographical region here.

California horsechestnut or California buckeye, Aesculus californica, is one of the more unusual native species. It is so in tune with the climate that it makes other deciduous trees seem to be inexperienced. Of course, to those who are unfamiliar with it, it just looks dead right now.

In chaparral climates of California, some deciduous trees start to defoliate early, before the weather starts to get cool in autumn. California sycamores, for example, can start to defoliate late in summer if the weather gets too warm and dry for them to want to hold their foliage any later. Such defoliation is more the result of minimal humidity than the result of chill.

California horsechestnut takes this technique one step further, by shedding spring foliage even earlier in summer, then refoliating once the rain starts in autumn, and then defoliating again as the late autumn foliage succumbs to frost through winter. It is ‘twice-deciduous’. It is a weird process that should not work, but obviously does.

It seems like a tree that is defoliated most of the time would exhaust its resources and wear itself out. However, California horsechestnut somehow stores enough resources to produce weirdly big seeds. These in the picture above are the same that were featured in ‘Six on Saturday‘ last week, while they were still in their husks.

Squirrels might chew on a few of these seeds, but do not bother storing them. They are mostly ignored by wildlife, perhaps because of their objectionable flavor. So, without squirrels to bury them, they fall to the forest floor near the trees that produce them, where they are too bulky to sift through the detritus to reach the soil below.

It makes one wonder why they put so much of their limited resources into seeds that are too big to reach the soil, but unappealing to wildlife that might otherwise disperse and bury them.

They know what they are doing.

Once the rain starts, and the seed sense that the weather is damp, they germinate on the surface of the detritus on the forest floor, and extend their tap roots through the detritus to the soil below. The seeds are too bulky to reach the soil directly, but contain all that their primary tap roots need to survive without desiccation until they reach the damp soil.

 

Western Sword Fern

90911Within its natural range on the West Coast between the southern extremity of Alaska and the southern extremity of California, Western sword fern, Polystichum munitum, is the most common of the native ferns. A few disjunctive wild colonies live as far inland as the Black Hills of South Dakota. Yet, with few exceptions, Western sword fern is difficult to cultivate outside of the natural range.

A fern that is so resilient and undemanding seems like it should be more adaptable. Although foliage is fuller and richer green with regular watering and occasional fertilizing, established plants do not need much at all. They survive in the wild here, with naturally limited rainfall, and just go dormant if they get too dry. Symbiotic soil microbes might be their limiting factor in foreign regions.

The dark evergreen and pinnately compound fronds get about two or three feet long, but can get more than four feet long in damp and partly shady situations. They form thick mounds that mostly obscure lower old fronds that die after their first or second year. Since it is naturally an understory species, Western sword fern prefers somewhat rich soil, partial shade and shelter from dry wind.

Matilija Poppy

90703If California poppy had not been designated as the California state flower, Matilija poppy, Romneya coulteri, might have been. It was nominated, but was less popular at the time, partly because it was familiar only to those near its native range in Southern California. Some of us know it as ‘fried egg flower’, because the big and floppy white flowers with yellow centers look like fried eggs.

Matilija poppy is a big and bold perennial, with flowers that are bigger than any other native species. They can get more than six inches wide! These flowers stand on top of lanky stems that might get taller than six feet. The somewhat sparse and light grayish foliage has a uniquely bristly but also slightly rubbery texture. Individual leaves might be longer than six inches, with elongated lobes.

As a native of dry chaparral regions, Matilija poppy is very resilient, and does not need watering once established. However, to survive long and dry summers, it starts to die back early, so should get cut to the ground later in summer or early in autumn before it becomes too unappealing. It then stays dormant through winter before regenerating in spring. Rhizomes can spread aggressively.

Coast Live Oak

90522The valley oak of the Sacramento Valley, San Joaquin Valley, and coastal valleys to the west, is the grandest oak of North America. Within the coastal half of that range, and extending down past San Diego, the coat live oak, Quercus agrifolia, is a nearly comparable second grandest. The biggest subjects may be as tall as seventy feet, and nearly as wide, with trunks wider than ten feet!

However, there is significant variability. Trees in forest situations do not get as big, and may stay lower than twenty five feet, with shrubby branch structure. While the biggest can get older than two centuries, smaller trees may not live half as long. The canopies of exposed solitary trees might reach the ground, while more social or sheltered trees are likely to shed lower growth with maturity.

Coast live oaks are typically pretty gnarly, and many have multiple flaring trunks. The dark evergreen leaves are only about an inch or two long, and half as wide, with bristly teeth on convex edges. The narrow inch long acorns can be messy. Roots are very sensitive to excavation and excessive irrigation. Sudden Oak Death Syndrome prevents new trees for getting planted in many regions.

The Other Rhodies

P90504KThere are countless species and cultivars of rhododendrons. Some have been in cultivation for centuries. Their big bold blooms are spectacular against a backdrop of their dark evergreen foliage. They prefer shelters spots, and some are happy to bloom in places that are too cool and too shaded for other flowers to bloom so well. They are so impressive that no one notices that they lack fragrance.

There is certainly a lot of variety among rhododendrons. Some are low mounding shrubs, while other can grow as small trees with open branch structure. Flowers can be white, pink, red, purple, blue or maybe even yellow or orange. Most flowers have some sort of pattern within the main color, but some are solid colors. Nonetheless, regardless of all the variety, we think that we can recognize a rhododendron when we see one.

Then there is Rhododendron occidentale, the Western azalea. The flowers are sort of recognizable as either big azalea flowers or lean rhododendron flowers, but are quite distinct from what we think of as familiar rhododendron flowers. The color range is very different too, with more white, marked with yellow, pink or orange. Even more surprising is that the bloom is quite sweetly fragrant!

Foliage is also very different from what is expected from a rhododendron. Not only is it deciduous, but if well exposed, it can actually develop soft yellow, orange or brownish red color in autumn. Individual leaves are rather narrow and papery.

We have only a few Rhododendron occidentale at work. They are not as tolerant of the partial shade from the redwoods as the more familiar rhododendrons are. However, they do happen to be blooming exceptionally well this year, while the bloom of the more familiar rhododendrons is less impressive than it has been in many years.

Santa Cruz Island Ironwood

60504A few years ago, it was known as Santa Catalina Island ironwood. However, the rare subspecies native to Santa Catalina Island lacks the distinctively angular foliar lobes of the Santa Cruz Island ironwood, Lyonothamnus floribundus ‘aspleniifolius’. The evergreen compound leaves are about five inches long and four inches wide with three or five narrow leaflets, and look like chicken feet.

Young trees can grow at an impressive rate, but rarely get to thirty feet tall, which is only half as tall as they get in the wild. Most stay rather narrow, and shorter than a two story house. They work nicely in groves, but not as symmetrical groupings. Each tree has a unique personality and form, and some stay smaller than others. The finely shredding bark fades from cinnamon brown to gray.

Six inch wide trusses of tiny white flowers bloom late in spring or early in summer. These circular trusses are flattened, similar to those of toyon but larger. They fade to brown and can hang among the foliage for years. Older trees bloom more than vigorous young trees do. Deteriorating older trees can be cut to the ground and allowed to regenerate with fresh new growth from their stumps.

The Overlooked Trillium

P90407Other species must be more interesting than what is native here. There are supposedly as many species of Trillium as there are of Yucca; forty-nine. All but ten are native to North America. The others are in eastern Asia. They are desirable and respected perennials to those who are familiar with them. White trillium is the official wildflower of Ohio, as well as the official floral emblem of Ontario. Ours would not likely qualify for such status.

The few around here appear only briefly about this time of year, and bloom with these small purplish burgundy flowers. They are only a few inches high, so are easy to miss. By the time they get noticed they are finished with their bloom. Their foliage lasts only until the weather starts to get warm in late spring or early summer. During their brief season, they somehow manage to store enough resources to repeat the process for many years.

This particular species is supposedly known as ‘giant wakerobin’, or Trillium chloropetalum. It is so diminutive, that I can not help but wonder about those that are not ‘giant’. Others that I see around here have more rusty red or ruddy brown flowers that stay closed most of the time. Western trillium, Trillium ovatum, lives here too; and I may have seen its foliage without distinguishing it from giant wakerobin, but I have never seen it bloom.

The trilliums that are native here live in partial shade out in forests, but away from more aggressive plants. They do not transplant easily, and do not like refined gardens.

Other trilliums in other regions bloom with bigger flowers in white, pink, red, purple, pale yellow or green. They must be more impressive than ours, and should at least be more adaptable to home gardens and landscapes.

Toyon

90123Botanists took a while to contrive an identity for toyon, which is also known as Christmas berry and California holly. It was classified as a species of Crataegus, two different specie of Photinia and two other specie of Heteromeles before it was finally identified as Heteromeles arbutifolia. Meanwhile, the town named after it changed its name only once from Hollywoodland to Hollywood.

Toyon is native to the coastal chaparral regions of California and Baja California, as well as British Columbia, so it can be quite happy with minimal watering or none at all in home gardens. Too much water is likely to rot roots. Fire blight unfortunately seems to be more of a problem in refined landscapes than it is in the wild. Toyon can be pruned up as a small tree, but must not be shorn.

Where it competes with other trees, toyon can get more than twenty feet tall. Those that are well exposed are typically less than twelve feet tall, with nicely well rounded canopies. The evergreen leaves are somewhat serrate and narrow. Fluffy trusses of small white flowers bloom early in summer. Big hanging clusters of bright berries ripen in autumn and linger until birds eat them in winter.

Rhus diversiloba / Toxicodendron diversilobum

P81209This would be a good topic for one of my rants on Wednesday, except that it is too silly for that.

Many years ago, before I started writing my gardening column for our local newspapers, my colleague Brent and I used to exchange funny newspaper gardening articles. Some were obviously not written for local climates. Some were just very inaccurate. Back then, it was done by mail, so the articles were added to anything that we happened to be sending to each other at the time. If I sent him some seeds, I would add an article or a few from the San Jose Mercury News. If he sent my cuttings, he would add an article or a few from the Los Angeles Times. They eventually became the inspiration for my gardening column, when Brent and others told me that rather than making fun of the inaccuracies of the articles, I should provide accurate articles.

One of the silliest that Brent sent to me was an otherwise well written article about star jasmine. Most of the information about it was accurate, until it got to describing the colors of the exclusively white bloom. The article explained that star jasmine bloomed in vivid shades or blue, purple, red, orange and yellow; just about every color except for white!

Well, I topped that with an article about protecting Japanese maples from theft, which sounded crazy even before reading the article. There were three recommendations. The first was to surround the subject Japanese maple with razor wire. Ah, the ambiance! The second recommendation was to dig a hole about as big as a trash can and fill it with concrete with a curved piece of rebar to make an enclosed loop on top, and then chain the subject Japanese maple to it. How about we just do without a Japanese maple in the front yard in a neighborhood where we expect it to get stolen. The third recommendation was to plant poison oak around the subject Japanese maple. Yes, good old fashioned poison oak, Rhus diversiloba, which is also known by the more descriptive Latin name of Toxicodendron diversilobum, and commonly available at . . . . some nursery . . . . somewhere. . . . You know, one of those . . . . garden centers . . . . or something.

Silly? Yes! What is sillier is that poison oak really IS available from certain nurseries that sell native specie! What is even SILLIER than that incredible degree of SILLINESS is that one of the so-called landscape companies that I worked for in about 2006 actually procured some for habitat restoration outside of, but adjacent to a newly landscaped area on the banks of where the Guadalupe River flows through San Jose. Poison oak and other native vegetation needed to be eradicated for the installation of the new poison oak and associated irrigation system, because nothing is more natural than supplemental irrigation! Then, the ‘gardeners’ had to conduct regularly scheduled weed abatement so that poison oak growing from seed tossed by the pre-existing poison oak did not grow up and compete with the new poison oak in the new ‘natural’ ‘landscape’. We certainly would not want poison oak taking over the poison oak.

Okay, this is not Wednesday, so I will finish this rant.

Poison oak happens to provide some of the best orange and red autumn foliar color in our region where almost all of such color is simple yellow. Where it is out of the way and not bothering anyone, it is sometimes left to climb high into trees, where it colors almost as well as flowering pear. Yes, it is pretty, but I will not be planting any of it.P81209+