Online Plant Purchases Have Certain Risks

Many seeds can be found online.

So many plants that were difficult to obtain years ago are now much more available online. The internet does more than give everyone access to nurseries and seed suppliers that sell online. It also makes it possible to communicate with others who might want to share plants and seeds from their own gardens. The advantages are obvious, but there are innate problems with so many plants being too available.

Before humans started to relocate plants all over the world, plants were much more confined to certain regions. Once relocated to new regions, some plants naturalized and became problematic for the plants that were already there. Exotic (non-native) plants often had the advantage because pests that troubled them back home had not come with them.

For example, pampas grass had been confined to the Pampas region of South America. It was imported to California and Oregon because its fluffy flowers and graceful texture are so appealing. The problem now is that it naturalized, and continues to proliferate and crowd out native plants in coastal ecosystems, without natural pathogens to slow it down. The availability of so many more plants from so many more regions seriously increases the potential for the importation of invasive exotic plants, as well as plant diseases and even insects!

Another potential problem is that common names of plants can be very different in different regions. Now, this can be an advantage when seeds from a common yucca in Lubbock, Texas might actually be from the very uncommon plains yucca (Yucca campestris, which I recently purchases on Ebay!). The problem is that the yucca known as ‘Adam’s needle’ in Georgia may be a completely different species from what is known as such in Pennsylvania, Oklahoma or anywhere else. A plant described as a ‘mimosa’ could be a silk tree, a jacaranda tree, or any of several different acacia trees!


Weeding Earlier Rather Than Later

Rain makes weeds grow like weeds.

Weeding is not much fun. Some of us might enjoy the relaxing monotony of productive weeding. Realistically though, most of us would prefer to do something else in the garden. There is certainly plenty of other chores that need to be done now, after earlier rain, and before the weather gets significantly warmer. However, such weather is why it is important to start weeding earlier than later.

By definition, weeds are weeds, because they are unwanted. They get to be unwanted by dominating space and exploiting resources more aggressively than wanted plants. Some innately grow faster and more aggressively than most other plants. Some are innately prolific with seed. Some employ multiple tactics to gain unfair advantages. Weeding is how we help our gardens compete.

Weeds grow throughout the year. Most slow down through the dry warmth of summer, and many die off then. However, there are always some weeds growing somewhere. When they die off, it is only after they have dispersed seed for their next generation. Some generate a few generation annually. Some are perennial weeds, or even shrubs, vines and trees, which survive for many years.

Weeding is more of a concern now because the majority of weeds grow so much more aggressively after the earliest rain of winter. Warming weather later in winter accelerates their proliferation. This is the time of year that weeds start to crowd desirable plants. If weeding is delayed for too long, weeds eventually bloom and toss seed. Some weeds extend stolons to disperse vegetatively.

The good news is that the same rain that promotes the proliferation of weeds also facilitates weeding. Weeds are easier to pull while the soil is still damp than they will be as the soil dries later in spring and summer. Also, while weeds are still fresh and turgid, they are less likely to leave roots or stolons behind in the soil. They are more difficult to pull intact as they begin to deteriorate later.

Furthermore, weeding should be done before weeds bloom and disperse seed for subsequent generations. Some are sneaky and quick.

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+++

Wild Turkey

P90224This is a relatively new development. The first few arrived here only two years ago. By last year, a few more arrived to make a significant herd that split into two smaller herds. Now these two smaller herds are quite significant. If they continue to proliferate as they have been, they will become more of a problem. They are already shredding flowers and colorful berries that are within their reach, and digging up flexible irrigation hoses.
They are not really wild turkeys, since they are not native here. They are actually feral turkeys that escaped into the wild and naturalized. They may have moved in from surrounding areas, or they may have escaped locally. Turkeys have been roaming parts of Scott’s Valley and my neighborhood in the Los Gatos Hills for a few years. Much larger herds roam other regions, particularly the Diablo Ranges east of the San Francisco Bay Area.
My former neighbor knew how to select the good ones. They all look the same to me. When they showed up on the road at my home, I could just chase them to the neighbor’s home, where he would take what we wanted. They were so stupid that he probably could have grabbed the good ones rather than shoot them. It is amazing that they could survive in the wild so stupidly.
I suppose that it was good that they survived to keep the meat fresh. However, I am now concerned about how these exotic and prolific birds might affect the ecosystem. Are they taking food from other wildlife? Are they dispersing seeds of the fruits they eat differently from other birds who eat them and fly away to other areas? Are they providing too much food for predators, and allowing them to proliferate more than they should naturally?P90224+


P80915K.JPGJust about everything in this picture is icky! This species of pampas grass, Cortaderia jubata, is one of the most aggressive and noxious of the invasive exotic specie that have naturalized here. It seems to be incarcerated behind the weathered cyclone fence with barbed wire on top. The big water tank is is a harshly stark background. The tired old Douglas firs and ponderosa pines to the left and right seem to be unhappy here. The small coast live oak that is at least trying to make a more cheerful appearance is only oppressed by the surroundings. Only the clear blue sky above lacks the ick factor.

What is not visible in the picture is that there is no other flora in the area. Most of the area is covered with a thick layer of gravel to prevent vegetation from getting established close to the water tank. Weeds that manage to grow get cut down regularly. Only the pampas grass survives the ravages of the weed eater. It has been allowed to stay only because it has not yet been perceived to be a problem. It will probably be removed eventually as well. It would have been much easier to remove before it got so big. Now that it is blooming, it is likely to sow seed for more of the same.

Whomever gets the grim task of removing the pampas grass must contend with the nasty ‘razor grass’ foliage. The very sharp and very finely serrated edges of each leaf cause the worst sort of paper cuts! Even if handled very carefully, the long strap leaves have a way of getting everywhere. Someone tugging the base of the foliage with gloves and long sleeves can lose an ear to just one of the many long leaves that whip around so aimlessly.

However, someone who is unfamiliar with the serious nastiness of pampas grass might see this picture very differently. The firs, pines and oaks are not so bad. The water tank is a neutral background to the subject matter. The weathered cyclone fence with barbed wire on top, . . . well, let’s just say, . . . it’s ‘abstract’. Anyway, to someone who does not know better, the fluffy floral plumes of pampas grass that toss so many seed that have the potential to grow into an indefinite supply of the same nastiness are actually quite pretty.P89015K+.JPG

Scarlet Pimpernel

P80826It is pretty but pervasive. Actually, I do not really find scarlet pimpernel to be all that appealing, but this is how someone who reads my gardening column in the Santa Ynes Valley News describes it. Embarrassingly, she requested that I discuss scarlet pimpernel while it was more of a problem back on June 7, but I only recently read the message. By now, it is already dying back for autumn, and is completely deteriorated in dry and hot exposed areas. It will be back next spring, and will bloom with tiny peachy orange flowers so that it can throw tiny but ridiculously abundant seed by summer before anyone notices. Flowers can be other colors in other regions. The sprawling stems can spread more than a foot wide, and can get up to about ten inches high if sprawling over other weeds. The tiny and soft leaves are arranged in opposing pairs. Scarlet pimpernel may not seem like much of a threat now that it is deteriorating, but new seedlings will be profuse early next spring, and can compete with seedlings of more desirable plants.
Control of scarlet pimpernel is not easy. If application of herbicide is an option, it does not stick to the foliage of scarlet pimpernel very well, even with a wetting agent. Hoeing eliminated larger plants, but does not kill the seed that the larger plants have already tossed. Scarlet pimpernel starts throwing seed so early that it must be pulled as soon as it appears in very early spring. Like I said, it is not easy. The small plants are not even easy to see. The process must be repeated at least weekly for a while, just because some seedlings will emerge after the first batch is gone.
Fortunately, scarlet pimpernel is not very vigorous. If it comes up through mulch, only a few plants will survive, and they will be easy to pull. They do not compete with other more vigorous plants well either. Many simple ground covers will simply shade it out, although it can mingle with and ruin some of the finely textured ground covers like baby tears and thyme.
I am sorry that I do not have any more information about scarlet pimpernel than is commonly known. I am speaking primarily from experience, and my experience has not been as bad as with other more aggressive weeds. Scarlet pimpernel always seems to be around, but is not so much of a problem that I am too worried about annihilating it completely.P80826+

The Good Weed

P80616KOnce in a while, a stray seed of a plant that would normally be considered to be an invasive exotic species happens to grow in a spot where it happens to fit. Those of us who regularly pull up unwanted feral seedlings, are typically skeptical. We probably pull up many such seedlings merely because we do not trust them, or because we do not want them broadcasting their seeds elsewhere in the neighborhood. In our region, Acacia dealbata, blue gum eucalyptus, black locust, pampas grass, broom, poke berry and Himalayan blackberry get no consideration; and their seedlings should be removed as promptly as they are discovered. English ivy does not get much more consideration, but every once in a while, it happens to wander into a situation where it is allowed to stay.

Catalpa is one that we are not quite sure about. It is an exotic species that happens to disperse unwanted seed at times, but is not invasive enough to warrant prompt removal of all seedlings. Many seedlings appeared in the area several years ago, and most were removed because of where they were. However, if any other seedlings have appeared since then, they have been discreet enough to remain unnoticed. It was as if there was a very specific mating season. Catalpa had not been invasive prior to that, and has not been invasive since.

Two of the feral catalpa seedlings appeared on the edge of the parking lot at the Felton Presbyterian Church. One became disfigured and distressed, and finally died before being removed. The other just happened to be in the middle of a parkstrip, and in a location where a good sized shade tree had room to grow. Because no one could find a good reason for removal, it stayed. After only a few years, it is now a good sized and very well structured shade tree that blooms nicely this time of year. It may not last long, since catalpas are short lived, but for now, it is a nice component to the landscape. This weed gets a happy ending.


Six on Saturday: Blackwood Acacia


Blackwood acacia, Acacia melanoxylon, happens to be one of my least favorite trees, but it does happen to be rather interesting. Mature trees have no leaves. Really. I don’t mean that they defoliate through winter and refoliate in spring. Only juvenile growth has bipinnately compound leaves. As growth matures, leaves are smaller, and are outfitted with distinctively winged petioles. As growth progresses, the winged petioles, known as ‘phyllodes’, become more prominent, and lack vestigial leaves. Therefore, once mature trees outgrow their juvenile growth, no leaves remain.

I dislike blackwood acacia because it is an invasive exotic species, like Acacia dealbata, but not as invasive. Mature trees sucker profusely from roots to form groves of several straight and vertical trunks. Where they are not a problem, groves of mature trees are rather handsome, but do not last long before they start to deteriorate. Foliar liter has an herbicidal effect that inhibits weed growth, but also inhibits the growth of desirable plants. It also produces an objectionable aroma.

1. Juvenile leaves are bipinnately compound, like those of Acacia dealbata.P80310
2. Leaves become more diminutive with distinctively distended petioles as growth matures.P80310+
3. Adult foliage is comprised exclusively of phyllodes, without leaves. The phyllodes function and look just like simple leaves.P80310++
4. Blackwood acacia flowers are not much to look at. Even in full bloom, they are grungy yellowish white.P80310+++
5. At least the bark is handsome.P80310++++
6. The best blackwood acacia is a dead blackwood acacia.P80310+++++
This is the link for Six on Saturday, for anyone else who would like to participate:

More Misplaced ‘Environmentalism’

P80214Nature has been getting by just fine for a very long time before humans started to interfere. It has survived all sorts of catastrophes literally longer than anyone can remember. It was here when dinosaurs were exterminated by a meteorite or comet or vulcanism or whatever catastrophic yet natural event finished them off. In fact, Nature was here for all of the few mass extinction events of the very distant past, including the Permian – Triassic Extinction, which only about 4% of life on earth survived! We all know that β€œIt’s not nice to fool with Mother Nature.”, or serve her margarine that tastes like real butter; but we should also realize that it is rather presumptuous to think that we can be more efficient with correcting all environmental damage. Very often, it is best to let nature do what nature does best.

For example, forest fires are perfectly natural. They are more frequent now because of human activity; but they are less extensive, likewise because of human activity. Humans contain fires that would naturally burn much larger areas. Preventing vegetation from burning allows it to accumulate and become more combustible. If deprived of fire long enough, vegetation within ecosystems that rely on fire as part of their natural restorative cycle eventually deteriorates, or become so combustible that when it does burn, its seed gets incinerated.

Many box elders along the San Lorenzo River have been dying for the past many years. We have not identified the pathogen associated with the necrosis, but it is probably a naturally occurring pathogen that is an intricate component to the natural ecosystem, (although after last winter, an inordinate number of box elders succumbed at the same time). Regardless, trees succumbed and fell. A significant void developed within the collective forest canopy on the Eastern Bank, near the Graham Hill Road Bridge. ‘Environmentalists’ wanted to ‘help’.

These new trees in the picture were planted within the area vacated by a few deceased box elders. The closer of the two is a coast live oak. The other is a bay laurel. There are a few more beyond those in the picture. Native vegetation that developed ‘naturally’ but happened to be in the way was removed to facilitate this project. To prevent native deer from damaging the trees as deer would do ‘naturally’ the trees were imprisoned in small cylindrical cages. Because the trees did not grow there and disperse their roots ‘naturally’, they must be irrigated until they can survive on what they get ‘naturally’ from rain.

The irony of all this is that native vegetation that was growing ‘naturally’ was removed to install ‘unnatural’ nursery grown trees intended to restore a ‘natural’ ecosystem that was already doing what it does ‘naturally’. Although native, the coast live oak ‘naturally’ prefers to avoid riparian environments such as this. It ‘naturally’ prefers a more exposed and drier situation. Bay laurel trees live there ‘naturally’, which is why a few had already started to grow from seed. These seedlings would not have needed to be caged or watered, but were removed to plant the new trees. Yes, bay laurels that would have survived on their own were replaced by bay laurels that must be watered and protected. Willows and cottonwoods that were quite prolific in the area were likewise removed, although many more remain lower on the bank of the River.

In the background, in the upper right corner of the picture, the bright yellow flowers of an Acacia dealbata can be seen. It is a seriously invasive exotic species that displaces native vegetation. Although it is impossible to exterminate the species, this individual tree that has been dispersing profuse seed into the San Lorenzo River for many years, really should be removed. Even if nothing were to be installed to replace it, the removal would benefit the ecosystem. Nature would have no problem finding native trees that would like to occupy that spot.

Invasive Exotics – Acacia dealbata

P80211Every invasive exotic (non-native) species has a story of how it got here.

Blue gum and red gum were imported to produce the timber needed for railroad ties. Many annual specie were forage crops for grazing cattle. Some got here by stowing away as seed on or inside cattle or other animals. Supposedly, mustard seed was broadcast by those traveling on the El Camino Real so that other travelers could find the route later. Then there are all sorts of invasive exotics that were imported simply because people liked to grow them in their gardens.

It is difficult to imagine why anyone would import any of the weedy specie of broom (Genista specie) or the sloppy species of pampas grass (Cortaderia jubata). It might have made sense at the time, before more appealing specie were introduced, or before less invasive modern cultivars were developed. Black locust has always been, and continues to be a pretty tree, long after more colorful and less invasive cultivars were developed. They were brought to California by prospectors from the East at a time when no one knew or cared how invasive they would be.

Acacia dealbata was likewise imported simply because it is a pretty tree, before anyone knew how it could naturalize and displace native vegetation and wildlife. Now it grows very rampantly in utility easements where other vegetation has been eradicated. Not only does it interfere with the efficiency of utility cables, but it is also combustible if ignited by sparks from electrical cables. Yet, it is so colorful and pretty in the middle of winter that it is not easy to dislike. Unfortunately, environmentalism is not what it used to be, and some so called environmentalists want it to be protected simply because it is ‘alive’.P80211+