Periwinkle

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Bloom is sporadic, but the delightful purplish blue color is worth it.

If the Latin name of dwarf periwinkle is Vinca minor, it is logical that large periwinkle should be Vinca major. Large periwinkle is more commonly known simply as periwinkle or common periwinkle, although it is not as common as dwarf periwinkle is, at least in landscapes. In some regions, it has naturalized as an invasive weed.

Some might accurately say that periwinkle is shabbier than the relatively neat and dense dwarf periwinkle. Others might say that it is just rustic or informal. The wiry stems stand less than a foot tall before they bend over from their own weight. Fallen stems can root where they touch the ground, and grow into new plants over winter.

The evergreen foliage is rich green, and a bit darker than the top of a billiard table. The simple paired leaves are about an inch and a half to two inches long. The slightly purplish blue flowers are about an inch and a half wide, with five petals each. Bloom is sporadic, but almost continuous, except for a lapse through winter.

Butterfly Bush

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Garden varieties are less likely to naturalize than the straight species is.

Many plants are so easy to grow that they become invasive weeds. Butterfly bush, Buddleja davidii, has done exactly that in some regions, and is only controlled here by the arid climate. Yet, once established, it does not need much water at all, and can survive on rainfall in some spots. They only want good sun exposure.

Mature plants can get more than 15-feet tall and half as broad, with long arching limbs. Most garden varieties stay smaller, and some do not get much more than six feet tall. The evergreen foliage is sage green, grayish green or chartreuse. The paired leaves are about the size and shape of willow or eucalyptus leaves.

Conical trusses of densely packed tiny flowers that bloom in mid-summer can be various shades of blue, purple, red and pink, as well as dusty white. Some new varieties bloom soft orange or yellowish orange. The more compact and colorful modern varieties are not as fragrant as old classics are.

Between A Rock And A Hard Place

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Where does this delightful columbine think it is?!

Columbine does not do well here. I do no know why. It does well enough in Colorado to be the Official State Flower there. Yet, the mildest of climates is Colorado are harsher than the climate here. It does not get too terribly warm in summer here. Humidity is minimal, but not as minimal as in much of Colorado. Nor does it exceed that of other regions where columbine does well.

We have certainly tried to grow columbine. It just does not work. Some of it succumbs to powdery mildew. Some succumbs to rust. The last batch just succumbed. Because it was expected, I did not bother to investigate. I got the impression that it was taken out by both powdery mildew and rust. Flowers that bloomed so delightfully when planted went to seed on their way out.

That should have been the end of it. I would not mind if someone tries again to grow columbine for next spring, even if it last for only a short while. I just do not expect to see it ever perform well here. None was planted this year. Even if someone had considered it, there was no need to add any prior to furlough, while cool season annuals for winter continued to bloom so happily.

What I certainly did not consider was the few seed that the last batch of columbine tossed almost a year ago. Apparently, at least one of those seed fell from the ledge where its parent plants lived briefly in now absent planter boxes, and into the edge of a small landscape below. It grew into an exemplary specimen of columbine, which is happily blooming as if it were in Colorado!

It is surrounded by a concrete retaining wall, a perpendicular granite wall and a big granite boulder!

 

Broom

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French broom seems to be indestructible.

Shortly after silver wattle finishes blooming up high, any of four species of broom begin blooming down low. Brooms and silver wattle often naturalize together. All bloom with the same delightfully brilliant yellow. The four brooms are French broom – Cytisus monspessulana, Scotch broom – Cytisus scoparius, Portuguese broom – Cytisus striatus and Spanish broom – Spartium junceum.

Sadly, none are desirable species. All are exotic weeds. They are only a topic for gardening because they are so aggressively invasive. Not only do they overwhelm and displace native species, but they also enhance soil nitrogen to promote the growth of other exotic weeds! They are unpalatable to deer, and are not bothered by insects or disease. Furthermore, brooms are combustible!

It is best to enjoy their cheery bloom from a distance, where they grow wild where they really should not. The various species tend to dominate distinct regions, with some degree of mingling. Big specimens can get eight feet tall, but do not live long as they are replaced by herds of seedlings. French broom is the only evergreen species; but any can defoliate in response to hot dry weather.

Wild Strawberry?

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Wild strawberries are worth salvaging.

Under a bank of carpet roses that I am none too keen on, this grubby ground cover competes with more aggressive weeds. To me, it looks like common mock strawberry, Potentilla indica. I never gave it much though. It seemed to me that whoever had installed cheap and common carpet roses on that bank would have employed a comparably cheap and common ground cover.

The ground cover was more prolific in open spots that were too narrow for more of the roses, and from there, seemed to have migrated under the roses as a second layer of ground cover. It would not have been installed underneath intentionally. It did not occur to me that it may have grown from seed like so many other weeds there, or migrated in from the surrounding forest.

The white flowers did catch my attention though. I was not aware of a mock strawberry that bloomed with white flowers. I really was not concerned enough about it to investigate. This part of the landscape will be getting renovated soon anyway. The roses will be relocated to where they can not extend their thorny canes into an adjacent walkway. Agapanthus will replace them.

Now that I am seeing more of these odd strawberries, I am wondering if this low ground cover that I formerly had no regard for is actually the native wild strawberry, Fragaria californica. Not only should mock strawberry bloom with yellow flowers, but it should also produce more spherical berries. Now I will need to identify it before I either dispose of it, or merely relocate it.

I prefer to not salvage exotic species that exhibit potential to naturalize from landscaped areas into surrounding forests. If this ground cover is wild strawberry, it migrated from surrounding forests into a particular casually landscaped area.

Unidentified Cyclamen

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What species is this naturalized Cyclamen? hederifoliumcoum – feral persicum – or something else?

Could this be Cyclamen hederifolium? Perhaps it is some sort of Cyclamen coum, or possibly feral Cyclamen persicum. I really do not know. Common florists’ cyclamen is the only cyclamen that I have any experience with. I grew it as a perennial when I was in high school, but never saw any feral colonies growing from self sown seed. I have never met the other species before.

Several colonies of this naturalized species of Cyclamen grow wild in the garden of a colleague. No one knows how they got there. I noticed them while procuring specimens of what might be other species that I have been wanting to grow, even though I am not certain of their identities either. I suspect that one could be Sorbus americana, and that another could be Rhus glabra.

I have been wanting to try growing Cyclamen hederifolium or Cyclamen coum since I saw it in pictures of home gardens in other regions. It looks something like common florists’ cyclamen that I enjoyed growing so many years ago, but more natural and relaxed. As much as I like florists’ cyclamen, the brightly colored flowers look a bit too synthetic for naturalistic landscapes.

Even though interesting species of Cyclamen have been available online and from mail order catalogs for at least the past several years, I have been hesitant to try any. I just do not know if they would be happy in forested landscapes where I want to grow them. Not many perennials perform well with so much overwhelming and mildly toxic debris from redwoods and live oaks.

Now I can see that they perform well enough here to naturalize, even under big and messy coast live oaks. In fact, I am now concerned that they have potential to become invasively naturalized in surrounding forests.

Field Of . . . ?

P91228KThis . . . was a ball field. It might eventually be one again. The old backstop at the upper left corner of the picture is almost completely obscured under a thicket of blackberry brambles and a fallen boxelder. It would need to be replaced. So would the decommissioned irrigation system, all the bases, the basepath, the turf . . . and everything else that goes into a functional ball field.

The turf had naturalized and overwhelmed the basepath long before last year. I collected wild mustard, radish and turnip greens from around the perimeter last spring and summer. By the time they were finishing, the blackberries were ready. I got stinging nettle from the bank of Zayante Creek in the background of this picture. Dock is already regenerating off to the far right.

There are naturalized wildflowers here too. I got pictures of perennial pea, purpletop vervain, Saint John’s wort, four o’clock, calla, narcissus, teasel, common thistle and California poppy, all within the perimeter of this ball field. Native trees include Douglas fir, California bay, California buckeye, bigleaf maple, white alder, cottonwood, coast live oak, canyon live oak and redwood.

The ball field looks like the moon now only because a construction company used it as a parking lot for trucks and machinery. We dumped excess soil removed from landscapes on the infield, where it was evenly dispersed by the machinery before it left. A low mound of road debris remains just past the foul line in the background. Firewood gets stocked out of view to the far left.

Restoring this meadow to a ball field would be like starting from scratch. The only salvageable asset is the flat space. Even though turf would be the most substantial feature of a finished ball field, a restoration project will involve more engineering and construction than horticulture.

California Pepper Tree

00101It has been naturalized in Southern California long enough to seem to be native. California pepper, Schinus molle, is actually endemic to Peru and adjacent arid regions of South America as far south as Central Argentina. Furthermore, although its small pink fruits with hard black seeds are sometimes used for culinary purposes, it is actually not related to black pepper, and is mildly toxic.

California pepper is as at home here as the name implies. Established and naturalized trees can survive on annual rainfall. They are better foliated if watered a few times through summer, and do not mind average landscape irrigation if their soil does not stay too damp. When they are not dropping a few leaves, they are dropping floral frass or dried berries, so their mess is considerable.

Old trees can eventually get forty feet wide, and almost as tall. Young trees grow rather aggressively. Growth slows with maturity. The distended and irregularly structured trunks and main limbs are picturesquely gnarly, with handsomely flaky tan bark. Foliage and outer stems are delightfully pendulous. The pinnately compound leaves are finely textured, and about three to six inches in length.

Four O’ Clock

40910Not only does it start to bloom late in summer, but as the name implies, four o’clock, Mirabilis jalapa, blooms late in the afternoon to attract nocturnal moths for pollination overnight. By morning, the white, yellow, variable pink or rarely pastel orange flowers are closed, and their yummy fragrance is gone. Individual flowers often display irregular stripes or blotches of alternate colors, and can be divided into zones that are shaped like slices out of a pizza. Plants get nearly three feet high, but then die to the ground with the first frost. They regenerate from big tuberous roots as winter ends, and can seed profusely.

Cortaderia jubata

P90908It is known by a few different common names, including ‘Andean pampas grass’, ‘purple pampas grass’, and simply ‘pampas grass’. ‘Andean pampas grass’ sounds almost like an oxymoron, since the Andes Mountains are in a separate region to the west of the pampas region of Uruguay and eastern Argentina. ‘Purple pampas grass’ is even sillier, since it is devoid of any purple.

I know it simply as ‘papas grass’. That is just how I learned it. The problem with this common name is that it is the same common name of Cortaderia selloana and its cultivars, which is a distinct species that is, on rare occasion, planted intentionally in landscapes. Cortaderia jubata is one of the most aggressively invasive of exotic species on the West Coast, so is not planted.P90908+

Cortaderia selloana is safe to plant because it is ‘supposedly’ sterile, so can not naturalize. Technically though, it is not really sterile, but merely exclusively female, without male flower parts for pollination. It reproduces by apomixis, which is a fancy way of saying that it produces viable seed without pollination. No one has bothered to explain why that makes it any less invasive.

Cortaderia jubata reproduces by apomixis too, but makes much more of problem with it. It is very prolific with its unpollinated seed! To make matters worse, it will hybridize freely with Cortaderia selloana if it gets the chance. How does that even work?! Pollen is needed for that sort of hanky panky! Nonetheless, the hybrids are almost as aggressive as Cortadera jubata is!P90908++

I just don’t trust any of them. Cortaderia selloana cultivars can work well in large landscapes in urban areas, where they can not escape into the wild. For rural or suburban landscapes that are near wildlands, there are plenty of other less invasive options.P90908+++