Wednesday, December 18, 2013

Scale on Ginkgo, Keeping Peacocks Away from Seedbeds, Bright Red Japanese Wax Plant, Blooming Paperwhites, Dueling Plant Guys

Scale on Ginkgo Leaves

A landscape designer and consultant brought this one in; it's Ginkgo biloba leaves coated with scale. Any other time of year this would be met by an immediate call to Gevork Arkelian over at the Agriculture Commissioner's office but not now -Ginkgo is a deciduous tree and, like all other deciduous tree, is losing its leaves. Right before the leaves drop they're susceptible to all kinds of infestations, most of which are not a concern because soon they will be gasping their last as the leaf they are attached to falls to the ground and rots away. 
Possible Red scale on Ginkgo leaves. 

'Wildflowering' Display is Planted

The artist collaboration 'Wildflowering L.A.' consists of several sights around the city devoted to planted displays California native wildflowers.  Our contribution has been planted and if you go there you will notice our Peacock avoidance strategy -ribbons of bright reflective mylar tied to posts. This seems to be working pretty good for keeping peacocks away. The Canada geese are another story; they're kept at bay with a stylized coyote sculpture that is moved at least once a day. 
Wildflowering L.A. Display

Brilliant Color Change on Japanese Wax Tree 

The Japanese wax tree (Toxicodendron succedanea) is an unassuming small tree located in the Asian, North American section. It really shines in the fall when its leaves turn the most brilliant red of any tree in the Arboretum. Be carefull however, if the genus name of this plant sounds familiar it is; Toxicodendron is the genus name for poison oak and ivy, and yes, if you touch these beautiful leaves the next red thing you will be the itching, oozing rash where you were exposed to it. 
Japanese wax tree. 
Paperwhites in the Meadowbrook section. 

Garden Show Host Nick Federoff Taping Segments Here at the Arboretum

I was honored to meet PBS garden show host Nick Federoff when he was filming for his show here at the Arboretum. Nick's been a perennial garden show host starting back in 1988 when he started his now nationwide syndicated live question and answer show.
I show Nick Federoff what would happen if he ever strays on my turf again.

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Saturday, December 7, 2013

New Pest on Fan Palm?

Small pest that is causing the leaves to be disfigured and coated with a white waxy layer can be seen in this photo.
Sometimes it gets exciting around here (at least for a plant pathologist-botanist like myself). A client brought a sample of a frond from his Mediterranean fan palm (Chamaerops humilis)with a pest that I have not seen before. A cursory search of the Internet turned up palm aphid, but this pest did not look like the adult form. I'm going to send these photos to the Ag. commissioners  office and find out what they know.


I've checked with palm expert Don Hodel at the Los Angeles Agricultural Extension offices and it turns out that the white substance is not from the aphid but from the palm. The pest in question may be a palm aphid, and is mostly harmless to the plant. 

Notice waxy coating and disfigured fronds.

Small pest -it could be a white fly, aphid or scale...or something else.

Another closeup of the waxy coating left by the pest and the pest itself (small spots on the leaves).
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Wednesday, December 4, 2013

In Plant Information Class Today We Looked at Color, LED's, Fractals and More...

For those who attended Plant Information class today here's a list of the links I mentioned and some I didn't mention as well:

Feng Shui and Garden Design:

Feng shui garden design may be good way to design a relaxing garden:

6 Easy Steps to Feng Shui Garden Design
baguaMap1.jpg (400×400)
Residential-Bagua-Map1.jpg (640×480)

...but just keep in mind the concept that we are prey and like to see what can sneak up on us and you've got a lot of what feng shui is about. 

New Outdoor LED Lighting and Gardens:

Outdoor lights have come a long way since the low powered 'Malibu Lights' of the past. Right now chinese factories are pumping out all kinds of outdoor LED lights, including spot lights, string lights, LED fluorescent lights etc. and their varied spectrums and energy saving properties now make outdoor lighting almost environmentally responsible (attention still has to be paid to observatory obsoleting light pollution and possible plant and algae growth considerations, but at least these don't rule out LED lights altogether, they just mean you have to pay attention to the wavelength of light coming from them -something that's easy to do with most LED's discrete wavelengths). Check out these links below to examples of LED's used in landscaping and companies offering LED outdoor lighting. 

Interior. Beautiful Minimalist Garden House Interior Design: Glowing Blue Colored Fences For Garden House ~ Ciiwa
led landscape lighting - Google Search
Lee Eunyeol’s Stunning LED Landscapes Light Up the Night Starry Night by Lee Eunyeol - Gallery Page 4 – Inhabitat - Sustainable Design Innovation, Eco Architecture, Green Building
LED Light Bulbs, LED Lighting, LED T8 Fluorescent Tubes - LED Liquidators Inc.
CabLED 6 ft. Indoor/Outdoor LED Ribbon Light Starter Kit-S008K35HW-A0-A1 at The Home Depot
Outdoor Led Ribbon Lights, Outdoor Led Ribbon Lights Products, Outdoor Led Ribbon Lights Suppliers and Manufacturers at
Accent - LED Landscape Lighting

Fractal Garden Design:

Something that's not been used much in garden design but should be are fractal based designs. Check out the links below for some fractal gardening ideas, including Arthur C. Clarke's explanation of fractals and several pages showing fractal generated landscapes. 

The Garden of Cosmic Speculation | That's How The Light Gets In
Fractal Gardens Can Be Rolled and Arranged into Infinite Patterns | Inhabitat - Sustainable Design Innovation, Eco Architecture, Green Building
▶ Weird planet II - Amazing 3D fractal landscape - YouTube
Purity Ring - Lofticries - Fractal Landscape - YouTube
▶ Crazy Fractal Worlds - Terrain Rendering 3 - YouTube
Fractals in Nature - YouTube
Fractals - Hunting The Hidden Dimension [Full - Hd 720p] - YouTube
Deepest Mandelbrot Set Zoom Animation ever - a New Record! 10^275 (2.1E275 or 2^915) - YouTube
Arthur C Clarke - Fractals - The Colors Of Infinity - YouTube
Imaginary Voyages Pt 7 Fractals and Soundscapes - YouTube
Imaginary Voyages Pt 4 Fractals and Soundscapes by Landscape Windscreen - YouTube
Deepest Mandelbrot Set Zoom Animation ever - a New Record! 10^275 (2.1E275 or 2^915) - YouTube

Color and Gardening:

The links below (especially the PBS video) are good primers on using color in the landscape. 

The Effect of Color (PBS Video)
Landscape Basics: Color Theory | CAES Publications | UGA
▶ The Garden Gurus - Psychology of Colour - YouTube
The Garden Gurus - Psychology of Colour - YouTube
Using Color in the Landscape

English vs. French Gardening:

Ever wonder why class-based Great Britain did not experience a class revolution like the French did? The answer might well be the type of garden design that became popular just after the French Revolution in England; the Parkland style -a style that incorporated the aristocracy's estate landscaping into that of the English countryside, thereby fostering a sense of stewardship rather than the feeling of ownership fostered by the 'outdoor room' style of French estate gardening in pre-revolution France. So... Lancelot 'Capability' Brown's Gardens:

▶ Sheffield Park Garden! USELESS TREES - YouTube
British Gardens: Stowe & Herstmonceux - YouTube

With that of the French emperor:

▶ Versailles, from gardens to Trianon palaces - YouTube

...which one would you feel more comfortable in (assuming you didn't own them). 

Friday, November 15, 2013

When Good Trees Commit Suicide

Susan's Eucalyptus
Q. I have a problem with my Eucalyptus. It has strange openings in the bark at the bottom that have some amber and black colored sap like deposits.  Mostly it just looks like it's suffering from something and has been like this, and slowly worsening for about 7-8 years.  We live about 17 blks from the beach in Santa Monica.

A. It appears your tree may have tree girdling roots’. This happens when a root somehow curls around the underground portion of the stem and physically prevents it from growing wider. The evidence? Where your tree comes in contact with the ground there is very little flair to the trunk (in other words it doesn’t taper out towards the bottom like it should). This can cause the tree to have dieback, seem less vigorous and eventually lead to catastrophic failure.

Sometimes girdling roots can be repaired, but generally it’s a good idea to remove the tree if its failure would damage property and/or have a high probability of causing injury or death. 
Tree showing signs of girdling roots. 

Notice lack of root flair near the base of the tree; this indicates tree girdling roots. 

Friday, November 8, 2013

PSHB Infestation at Local Park.

California native sycamore showing rusty stains and small holes indicative of the Polyphagous Shot Hole Borer. 
A large local park in the San Gabriel Valley has an extensive infestation of PSHB  that has killed or damaged what appears to be 10% of its tree canopy. The two most affected plants are California sycamore (Platanus racemosa) and White alder (Alnus rhombifolia). The extent of this infestation here in the San Gabriel valley is quite significant and could change the the way we use trees here.
Alder bark showing PSHB hole and staining.
One of the things that might be exacerbating this infestation is the long period of drought we are currently in. There has been only one year of normal rainfall here in the L.A. area since 2005. Ground water levels are low and this can put huge amounts of stress on large trees that rely on groundwater such as Alders, Sycamores and Oaks. Extra water may not be the answer because it might not be possible to supply the amount needed for large trees solely through irrigation.

White alder 3/4 dead from PSHB
One of the things that might have to change is the tree density here. If you look at historic photos of Los Angeles you notice large areas of treeless plains. There is a reason for this; these areas were mostly grasslands and could not support large trees without irrigation.
California native sycamore infested with PSHB
Cottonwood tree growing in undeveloped river bottom showing possible PSHB infestation.
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Tuesday, October 22, 2013

Hedge Trimming Pro

Check out the moves and the equipment displayed by Monrovia Nursery's Ignacio Morena as he prunes the brush cherry bushes located in near the Gazebo.
Notice the custom guide fashioned to attach to the gas powered trimmers blades. This guide allows him to use the feel of the hedge pressing against it to keep him from making too deep a cut.

Saturday, October 19, 2013

Ficus Whitefly: New Pest Showing Up Here Can Defoliate Ficus Hedges

Ficus benjamina leaves showing whitefly eggs and yellow mottling from feeding stress.
I have had numerous reports now of a new pest that is attacking and defoliating ornamental (but not edible ficus). The ficus whitefly has been showing up in the San Gabriel Valley this summer and fall after first appearing last year in west L.A.. The pest is recognized by the presence of small, white flying insects, egg cases that appear to be scale, and an immature form that looks like a crawling mealybug. Heavy infestations are usually accompanied by copious deposits of sooty mold covered honeydew. The combination of the stress put on the plant by the feeding of the insect and the decreased amount of sunlight the leaves receive due to the sooty-mold covered honeydew deposits can cause the ficus plant to completely defoliate.


Heavily infested Ficus benjamina leaves showing egg casings and yellowing leaves due to feeding damage.

Above: Ficus whitefly egg casing just above a hatched lace-wing egg casing. The lace-wing eats the whitefly.
So right now the only treatment for these pests are to use soil drenches of imidacloprid. Since Ficus plants do not produce bee attracting blooms this shouldn't be a problem for bees (make sure you have no bee attracting plants anywhere near the area where you are applying the imidacloprid).

Here's a video produced by Florida state agricultural officials regarding the pest:

Luckily, as the picture of the hatched-out lacewing egg casing shows, local predators will acquire a taste for these pests and over the next several years and infestations will become less and less damaging. Still, this is not the first, nor the last pest to attack the ubiquitously planted Ficus plant; here is a list of other ficus pests to look out for. 
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Thursday, October 10, 2013

Wednesday, October 9, 2013

False Spring Has Arrived

Our cool summer followed by a brief but intense period of heat has tricked some plants into thinking it's spring again. This 'False Spring' is pretty common here in Southern California, happening at least once every 5-10 years here or more. The fun thing about these not-so-common weather patterns is that they seem to affect different plants each time. This year our 'False Spring' has caused our 'Tower of Jewels' (Echium wildpretii) to bloom out of the seemingly dead clumps of last years plants. Since 'Tower of Jewels' is a biennial, I guess these would be 'triennials'.

'Tower of Jewels' (Echium wildpretii) blooming in fall from an old, mostly dead bloom cluster from last season.

Magnolia X 'Galaxy' blooming out of season due to the 'False Spring'.

 Fuzzy critters attacking oak trees? No, just a type of gall wasp that causes a furry but benign gall to appear on the leaves.

Live-oak wooly leaf galls.
 Hops (pictured above) are the female flowers of the hop plant (Humulus lupulus)extensively used in the beer industry as a flavoring and stabilizing agent. These are growing in our herb garden.
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Friday, October 4, 2013

Plant Identification Class Starts Today

My plant identification class starts today at 2pm. We'll be doing a lot more field work in this session so I'll be posting Google photo albums with pictures of the plants we'll be working with as well as their locations. I've also started a new blog that will have links to these photos as well as links to identification sights and other useful information.

Friday, September 27, 2013

Devil's Coach Horse Beetle

Ocypus olens
This fascinating looking insect was found walking across the road in front of the Peacock Cafe. It is a type of beetle known as a 'Rove' beetle. This particular species (Ocypus olens ), is a European native that was introduced to Los Angeles sometime in the early part of the 20th century. They feed on snails, slugs, earthworms and other invertebrates  If you see one here at the Arboretum please enjoy it from affar, although they don't sting they are rumored to have the ability to use their powerful front pincers to deliver a rather painful bite.

Defensive posture of Ocypus olens, see those pincers! They gonna bite ya. 
Ocypus olens in a more relaxed state. 

Thursday, September 26, 2013

"Pumpkin on a Stick" Is Not

Now that it's Fall you'll probably see this thing in flower shops -it's marketed as 'Pumpkin on a Stick" It's not a pumpkin at all nor is it closely related, it's Solanum aethiopicum, also known as the Ethiopian nightshade. Is it invasive? Is it poisonous? Where did it come from?

It is not on the USDA's invasive plant list, it is not listed as poisonous and is widely eaten in Africa where it is native, but always use caution with anything in the genus Solanum (for some real unnecessary alarm read here about a poisoning involving a different Solanum species). That being said it can be grown from seed and can get 8 feet tall. It takes 70+ days to fruit so you should plant it in the first week of August to get fruit by Halloween.

Solanum aethiopicum

Friday, September 20, 2013

A Brush Cherry Apart

 This has always been intriguing to me -a variegated Syzygium australe. It appeared as a 'sport' on an otherwise green S. australe here and has remained stable (not reverting back to its green appearance) ever since.
Syzygium australe

Thursday, September 5, 2013

Plant Information Class Tour of Nuccio's Nursery

Seven hardy souls braved the 100 degree plus heat to show up at Nuccio's camellia nursery for a tour by owner Tom Nuccio. They weren't disappointed as Tom not only discussed the varieties of camellia they had to offer but  gave us tips on how to propagate them using seeds, cuttings and grafts.
Tom Nuccio shows off some of his species camellias from China and Vietnam.

These two and tree gallon pots are full of newly germinated camellia seedlings. Tom told us the trick was to plant the seeds as soon as the seed capsule ripens.
According to Tom camellias will root almost anywhere on the stem, so you need only one leaf node per cutting.
Tom shows us a newly rooted camellia cutting. 
Camellia cuttings root in Tom's mist house. 
Tom explaining that Dragon fruit cactus like climbing up smooth surfaces, like the bark of the citrus tree that this one particularly robust plant is growing on. 
Greenhouse full of newly grafted camellia plants. 
Tom's grafting secret? Mason jars are kept on the newly grafted plants until callous and new growth is observed. 
Tom points out new callous growth on a camellia cutting as well as a new leaf-bud. 
New growth on a camellia graft -Tom revealed that tipping the mason jar over just a bit the for two to three days before it is removed allows the cutting to acclimate before it is exposed to the drying southern California air. 
Tom also gave us a demonstration on how to do camellia cuttings. 
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Saturday, August 24, 2013

Tiger Bee Fly

A guest brought in a dead branch from a mulberry tree that had large tunnels bored into it. I recognized these tunnels as Carpenter bee galleries. Carpenter bees usually attack already dead wood so I wasn't too concerned until I saw this monster flying out of the gallery (luckily the whole thing was in a plastic bag). 
Tiger Bee Fly, about an inch and a half wide -he's a big boy.  
This was a Tiger bee fly. A very pretty and non-disgusting member of the fly family. And it east Carpenter bee larvae, in fact their was a Carpenter bee larvae mummy, probably the victim of the Tiger bee's own bee eating larvae, located just inside one of the tunnels (see below) 
Carpenter bee larvae mummy, a probable victim of the Tiger bee fly.
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