Thursday, November 1, 2012

*Update Possible Polyphagous Shot Hole Borer in the Wild on Coast Live Oaks

Just got back from a property located about 15 minutes northwest of here. The manager of the property found what looks like Polyphagous Shot Hole Borer on five Coast live oaks located in an historic stand in an unirrigated area. All five are dead or near dead, and the signs die back occurred within a months time. I am waiting on confirmation from Dr. Akif Eskelan and the folks at UCR, but it it isn't PSHB then its something that looks just like it. Below are images of the trees that were infested. If you see anything like this or what is described here, please contact me as soon as possible at 626 821-3236
Update: Akif Eskelan's lab has confirmed that this is NOT an infestation of PSHB (That's a relief). However it may be a previously unknown borer and fungus combination. 

-Frank McDonough, Botanical Information Consultant at the L.A. County Arboretum and Botanic Garden.

Possible Polyphagous Shot Hole Borer on Coast live oak (Quercus agrifolia)

Notice the dark, oozing stains that appear on the trunk. 

This almost dead Coast live oak has noticable soaking spots up and down its trunk. Most of these appear on the south side of the tree. 

Possible PSHB entry holes with oozing fluid. 

Tuesday, October 30, 2012

A Nuisance Bug that Doesn't Stink

A fellow employee here at the Arboretum brought this to me. It was massing outside of her house in large numbers. They seem to be making there way into her house and becoming a nuisence there.  It's about a 1/2 an inch long and has really nice red markings on its thorax and abdomen. Turns out this is the Red-shouldered bug . It's listed as feeding on the seeds of Koelrueteria trees so control consists of keeping the seeds raked up off of the ground. I asked my fellow employee if she had any Koelrueteria trees around and she said that, yes, she had three of them in the same area as where the bugs were a problem.
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Tuesday, October 16, 2012

Another Possible Polyphagous Shothole Borer Infestation in Altadena

Visible ooze possibly from PSHB infestation.
I received an email from resident of Altadena who had just had a large oak transplanted this last November. The tree was not doing so well and he was wondering what was happening to the tree. Turns out the tree may be suffering from PSHB infestation. Pictures of the tree he sent me seem to show the typical 3-6 inch small oozing spots with sometimes discernable small white spots of sawdust surrounding small 1/8" holes in the bark. This is just a photo diagnosis so it is no way the final word on this tree. Although live oaks are known to be reproductive hosts for the PSHB, how destructive they might be to oaks in good health is still unknown.

3" by 2" ooze spot and entrance hole (midway on the left of the spot).
Oak trunk showing ooze spot.

Oak canopy showing thinning. How much of this thinning is due to PSHB is unknown; the tree was transplanted less than a year ago.
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Thursday, October 11, 2012

Elder Blues

I got a call about a sick 'Alder' tree that was just about dead, turns out the tree was a Box elder, a type of maple tree with compound leaves that don't look like a maple. This tree is very confusing. It's also the number one victim of the new Polyphagous Shot Hole Borer (PSHB).  This pest is just hideous and seems to be gaining new victims (known in plant pathology circles by the innocuous term 'hosts') every month.I asked the caller to send me pix of the tree by email and sure enough, it was infested with  PSHB.

Here are some of the pix he sent me:

The Box elder's confusing leaves. 
Notice the dark wet-looking patches with the mounds of sawdust in the middle of them. 

An even better look at the oozing and the sawdust spots. 

Friday, October 5, 2012

(Possible) Shot Hole Borer Blues

The Polyphagous shothole borer is starting to make the news, and rightly so. Just last week I found one of our Brazilian peppers possibly dead from the beetle/fungus combination. 

Brazilian pepper tree (Schinus terebinthifolius) that may have been killed by shot hole borer. 

Closeup of branch from possible shot hole borer infested Brazilian pepper tree. The dark stains may be from the Fusarium fungus that the beetle infects the tree with. 
This pest/fungus combination is starting to show up all over the place -it's quite an extensive infestation. Just before I started writing this post a gentleman called about his tree that was dying and emailed me some photos of it; it was a Box elder. Box elders have been the canary in the coal mine for this thing and his was located in Monrovia. I'll be writing more about it shortly, and I'm writing more extensive article about the infestation for the Arboretum website.

Pest and Disease Threats to Southern California Oaks: I'll Be Presenting At This Seminar

Welcome! - Pest and Disease Threats to Southern California Oaks:

'via Blog this'

Saturday, August 11, 2012

Mount SAC Horticulture Department Tour

This months plant information class met at the Mount SAC horticulture department for a tour by production assistant Ruben Flores. Ruben showed us the new demonstration garden, the new turf demonstration garden and wiffle ball diamond, a production greenhouse devoted to Poinsettia production, and several interesting small garden areas that were chock full of lush plantings. 
The cactus and succulent demonstration garden; it was just planted the week before our tour. 
The new wiffle ball diamond; this was no easy project -the first batch of decomposed granite had to be replaced because it was contaminated with mud. 
We saw this pretty blue-flowered weed growing around the new ly constructed classrooms there. Solanum eleagnifolium is a member of the nightshade family that some consider a candidate as a water saving ornamental plant; problem is that it's also a weedy plant that is toxic to livestock. 
Our guide, Ruben Flores, started our tour in the houseplant greenhouse. 
A large production greenhouse devoted to growing Poinsettias. Their are bout 4800 of these growing in this greenhouse, if they were to sell these at retail for $10 a piece they would gross $48,000. 
Ruben shows us one of the hidden shade gardens. 
Hidden shade garden. 
The plants growing on the log in this greenhouse are orchids and ferns. 
Society garlic blooming in the hot summer sun. You can guess what this smelled like. 
A beautiful South African cycad. 
There was a large shade-cloth covered garden located in front of the horticulture department offices. Besides being a relaxing water feature the pond in the garden contained more than a few beautiful Koi.
Here's a diagram of the demonstration garden that's currently being installed at Mt. SAC. 
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Friday, August 10, 2012

Grafting Tomato Plants

One of the big problems with growing heirloom tomatoes is their lack of resistance to root diseases and nematodes. Grafting an heirloom variety on to a vigorous disease-resistant root stock not only gives the plant resistance to these disease, it can also lead to earlier fruiting and larger fruit as well. You can buy grafted tomatoes out of state (although right now plugs of a tomato graft called 'Might-Mato" are being sold by a California plug grower and may start showing up at retail nurseries here soon) , or you can try your hand at grafting your own. Tomato grafting usually requires a greenhouse, but you might be able to get results in a plastic tented area under shade-cloth.  Here are some videos and links that will help you get started:

North Carolina State pamphlet on tomato grafting. 

University of Connecticut IPM tomato grafting webpage. (sells tomato grafting kits)

Article on tomato grafting on "The Atlantic" magazine website. 

Tuesday, August 7, 2012

Where Can I See Examples of Mediterranean Gardening?

Q. I'm designing/planting out my back yard mediterranean style here in Santa Clarita. Can you tell me where I can go and see a nice example of this landscape style? Somewhere open to the public?
I'm having a blast learning all about this type of garden!

Thanks, Jenny

A. Hi Jenny,

We have good examples of Mediterranean gardening here at the Arboretum. Our entryway, South African section, South African aloe walk, Demonstration Garden, Canary Island Exhibit and our Water Conservation Garden are all good examples of plant selection that is appropriate to our Mediterranean climate here. Our sister garden in Torrance, the South Coast Botanic Garden , has a Mediterranean garden and there is a public community garden, the Arlington Garden, whose eclectic style consists mostly of Mediterranean garden elements. Below are some examples of Mediterranean climate appropriate gardening here:

The Undersea Garden's plants are perfect for Mediterranean climates like ours. 

South Africa receives most of its rain in the winter and then stays mostly dry for the rest of the year. This is a true Mediterranean climate so many of the plants that grow there are perfect for Mediterranean gardens. Pictures above is the aloe trail winding through the South African plant collection here. The exaggerated colors are the result of the setting sun.  

Our Demonstration Garden, located fairly close to the Arboretum's entrance, has several small sections devoted to Mediterranean and California native gardening. 

Saturday, July 28, 2012

Selected Questions From the Last Two Weeks

Was given an Ice-cream bean tree (Inga edulis).  Wanted to know how to grow it here.  Has it for 3 years under a huge Ficus tree in a pot.
Advised that it might not survive our winter because it would freeze over at 27F.
Also asked that if the tree successfully produces fruit to bring it over for ‘inspection’.
Her 40 years old cypress trees are dying.  She lives in Malibu.  She actually sent over some sample leaves to us by mail.
Told her the trees are dying from Cypress canker, a kind of fungi. Once your cypress get the fungus there is little you can do to prevent it from eventually killing the tree. Pruning can extend the life of the tree, but it is vitally important to disinfect your pruning equipment between each cut. One thing that really helps promote the fungus is the number of Italian cypress trees you have in your neighborhood and how close together your cypress trees are planted. Closely planted cypress spread the disease quite readily, and if your neighbors have lots of cypress planted nearby, they can serve as sources of infection for other Italian cypress in the neighborhood. Another reason you have the infection now and not 40 years ago (the fungus was first detected in the 1920’s) is that the range of this fungus has been slowly spreading over time

Cypress canker links:
Fungus from California suspected of killing cypress trees worldwide | Nature | The Earth Times
Gene sleuths trace tree-killing pathogen back to California
San Diego Master Gardeners - FAQ - Italian Cypress turn brown
Italian Cypress Video –
I work on the Master Gardner help line and have a question I do not know how to answer. I would appreciate any help you can give.

" I have a Liquid Amber question for Santa Monica. When do the trees defoliate, and for how long? I'm trying to plant a winter vegetable garden and my hope is the sun would shine between the bare branches. In the summer the sun is directly overhead avoiding the tree. "

Hi Rose,

Liquidambars here defoliate in late November early December or later (they’re seem to be the last to put on color as well) with re-foliation occurring around March through April. That could be different for Santa Monica because it is not as cold; they could re-foliate sooner.
Our 80-yr-old mission fig tree has splotchy yellow areas on its otherwise dark green leaves. The tree has lots of small green figs on now, but they seem a bit smaller, as do the leaves, from normal. I did some on-line research, and it could be fig leaf rust. How do we tell for sure? Could I send you a couple leaves to I.D.? What's the cure? We have a dog who eats figs - loves them - and will even chew on fallen leaves because they're so good! We don't want to use herbicides that will harm her or us or even the squirrels and other connoisseurs of these figs.

Here's some photos of one leaf, front & back, and of others on the tree.  I hope you can tell something by these photos -- it's more obvious in person.   We live in 90064 - in the NW quadrant of the I-10 and 405, west end of Rancho Park Golf Course.

Hi Paula,

Your fig looks like it has Fig Mosaic Virus. There is no cure; it’s best to get a resistant variety –Black Mission is the most susceptible to this virus which is transmitted by mites or by rootstock.
Spraying may work for rust, but not for viruses. However you can prevent the spread of the virus to other Fig trees by spraying for mites on a regular basis.

UC Davis page on Fig Mosaic Virus:

Thursday, July 19, 2012

Peach Tree is Dropping the Ball

Q. Can you help me resolve a problem that has developed with my two peach trees? They are now giving reasonably good quantity and good size fruit, but the problem that has developed is that the fruit drops before it is ripe. Is there anything that can be done to help the tree hold on to the fruit until maturity?

APeach trees regularly thin themselves out before ripening occurs; if this didn't happen the peach’s branches would break under the weight of the ripening fruit. In fact, when the peach starts to show signs of fruit dropping (it's starting to self thin) it isn't a bad idea to water the tree heavily and then, the next day, shake the main trunk gently but rapidly to thin out the juvenile peaches before they get too big and pose a risk of collapsing the branches that bear them.

Friday, July 13, 2012

A London Planetree in Pain?

London Planetree leaf (Platanus x acerifolia) showing symptoms of Mildew infestation.
I found this sitting on my desk with a note wondering what was wrong with the tree. No identification but the soft maple like leaves coupled with the the problem itself ruled out anything but the leaf being from a London Planetree (California sycamore leaves are similar but usually much larger). The problem is a fungus known as mildew. London Planetrees are susceptible to mildew, and the recent long period of cool weather has increased the amount of mildew I'm seeing on everything. Mildew is what is known as an obligate parasite, in other words it needs its host to survive so it will not kill it...but -it can make the tree look pretty bad, especially if its a variety that is not resistant to mildew. If the tree were in the wild this would not be a big deal, but here the life and death of trees is dependant on how we like them as ornamentals and a tree that is constantly coated with leaf curling fuzzy-white mildew could irk someone enough to consider removing it; thus curtailing its changes of surviving.

So what can be done to alleviate this blotchy leaf-deforming parasite? The best thing to do is wait -time will heal this as long as we have a summer that is somewhat close to normal. Hot temperatures and dry weather will desiccate the mildews branching, threadlike vegetative state and cause its existence to be less noticeable by us human beings who don't appreciate its leaf distorting fuzzy presence.
What about fungicides? Applying fungicides to large trees is, unfortunately, inherently expensive and dangerous. A spray service could do this for you but you'd be literally spritzing your money away.

There are varieties of London Planetree that are more resistant to mildew and another leaf disfiguring fungus called anthracnose; these include 'Bloodgood', 'Liberty' and 'Columbia' but unless the extended June gloom that we've been having that caused this problem in the first place becomes a permanent climate feature here I would just keep the tree you have and wait out the fuzzy invader. Also, remember to keep the old leaves picked up off of the ground -they could be the source of other fungal problems if you allow them to rot on bare ground. Many leaf attacking fungi are spread when infected leaves touch the bare ground and stimulate the production of fruiting bodies (the term for the mushroom like structures that grow off of the leaf that would be roughly analogous to a plants flower).
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Saturday, June 30, 2012

July Plant Information Class Will Be on the 11th at 1:30

Hey everybody just a reminder,  my plant information class held usually on the first Wednesday of the month,  will be held this month on the second Tuesday, July 11th at the usual time; 1:30 pm. This class is going to cover cactus and succulents. We're going to look at the major types of cactus and succulents (selected families and genus) and talk a little bit about strategies for developing a cactus and succulent garden like the ones you see at the Arboretum and the Huntington.  As always we're going to look at some of the most interesting, entertaining, and even strange plant information questions that the plant information volunteers and myself have fielded over the last month. I'm also going to be talking about a new pest, the 'shot hole borer'. This is an interesting pest that has already killed and damaged trees here in the San Gabriel valley.  you don't want to miss this meeting. Lastly,  it's hot, so were going to be, as usual, in the well air-conditioned plant information headquarters located in the library building here at the Arboretum. See you there!

Wednesday, June 13, 2012

One Messed Up Mulberry

A gentleman brought in a Mulberry (Morus alba) shoot from a tree that was having problems. The new foliage was distorted and seemed to wilt over the course of one to two months. According to him the onset was sudden and no other nearby trees (this was the only mulberry) seemed to have the problem. We ruled out a gas leak and upon viewing the shoot under magnification no insects or insect debris were noted.
Distorted Mulberry Shoot
After ruling out insects and diseases the last thing left was to investigate physiological (nutrition, salt burn, etc.) causes and finally, herbicides. Going through the list the only description I found that matched the damage to the shoot was that for 'phenoxy' herbicides (the giveaway was the curly-queue stems). One of the most common scenarios where this type of herbicide damages trees and shrubs is when 'weed and feed' lawn fertilizer is applied to the lawn under the canopy of a sensitive tree. The owner of the damaged tree however did not apply any of this kind of fertilizer on the lawn under the tree. Another cause of this kind of damage is a disgruntled neighbor spaying an herbicide intentionally on the tree, but the tree owner denied having any tiffs or feuds with fellow neighbors. 

So the most likely cause of this damage to his tree was a neighbors spraying accident. 'Phenoxy' type herbicides (those containing 2-4 D and similar compounds) are notorious for causing damage to trees from spray drift caused by applicator error or applying the spray in windy, hot conditions. All it would take would be a neighbor spritzing weeds in his lawn with a hose end, pump, or hand pump sprayer in a light breeze; and to top it off Mulberries are notoriously sensitive to these types of herbicides. 

The treatment? If the accidental dose is not to great the tree should grow out of the damage either before the summer or next spring when the tree re-leafs after its winter dormant period.

Saturday, June 2, 2012

This Wednesdays Plant Information Class -Tree Donor Tour - Plumeria Question

This Wednesday's Plant Information Class

This Wednesday, June the 6th Plant Information Class will be held in my office at 1:30. The topic will be about plant allergies and how to design a landscapes for those of us who dread spring for the pollen firing squad it is. I will also be introducing all plant information volunteers in attendance to an exciting new project that should get us all published.

Tree Donor Tour

I was honored to be a co-presenter on today's Tree Donor tour. We had about 50 people take the tour which gave an overview of the horrendous damage that occured as a result of the December 1st windstorm. In all we lost over 245 trees and 26 days of operation due to the storm. Arboretum Director Richard Schulhof, Superintendent Tim Phillips, Senior Biologist Jim Henrich, and myself hosted the 90 minute tour which also covered some of the new collections we'll be initiating as a result of the wave of donations recieved and the art exhibit curated by Leigh Adams that uses wood from the felled trees as the material for art created just for  the exhibit.  Here's a video 

The Damage

The tour covered the vast magnitude of the damage to the Arboretum and why some trees failed and others didn't. One of my favorites (in terms of examples of preventable tree failure) is the 150+ year Blue gum that failed as the result of the damage the tree suffered when a metal conduit was installed next to it in the 1960's. Other interesting tidbits were the decapitation of palm trees by the flailing limbs of the huge cypress trees next to them and the inability of large, tropical ficus to stand up to the wind.  

The Recovery

Right after the windstorm large areas of the Arboretum were inaccessible to vehicles, so the first thing that had to be done was road clearance. County fire crews and other county crews were invaluable for this. Brush clearance crews from parks, public works, agricultural commissioner's office and other county department personal came to our aid immediately after the storm. Call me a sentimentalist but it really struck my heart how these crews all seemed motivated by a feeling of admiration for the Arboretum. These guys were really motivated to get the Arboretum open again so that people could enjoy this place. Now all this enthusiasm and sentiment was great, but  the real stars, in my opinion, were Tim Phillips and Jim Henrich who both were able to steer the extremely enthusiastic crews in the right direction and ensure that the more sensitive parts of the L.A. Arboretum's collections were not compromised by that enthusiasm. 
One of the strategies Tim put in place that really helped keep the clean up from being more damaging than the windstorm was to make sure only Arboretum crews worked in sensitive areas. This included most of the road-inaccessible parts of the collection and the Tropical Forest area. 

Another incredible and heartening result of the disaster was the outpouring of support from the Arboretum from the public. We had hundreds of phone calls, emails and inquiries wondering what that individual could do for the Arboretum. That's when we started the tree fund; since then the fund has accumulated over $70,000 in donations. 

New Collections Started, Old Collections Renewed

Besides the tree fund one positive result of the storm has been an invigoration of our collections programs on several fronts.

Seed Acquisitions  

Jim Henrich has been acquiring seeds from index seminum (seed index)  lists from various botanic gardens around the world with concentrated focus on:

  • Australian Plants
    • Will probably focus on trees and shrubs that are less messy, less fire-prone, and flower more than previous Arboretum acquisitions as well as flowering perennials, both herbaceous and bulbs. 
  • South African Plants
    • The Southern California-like climate of the South of Africa and the Cape of Good Hope area will continue to be a source of acquisition for non-invasive specimens for our collection. 
  • South American Plants
    • With special emphasis on Chilean, Argentinian, Brazilian and Peruvian plants from climate zones similar to ours. One tree in particular that we hope to increase our collection of; the genus Tabebuia a south and central American flowering tree that has quite spectacular blooms and shows great potential as street tree here in L.A. County. 

Engelmann Oak Grove

The Arboretum's Engelmann oak grove is the northernmost pure stand of a remnant oak population that spanned an area from northern Mexico up into Arizona and over to the coast of southern California. In that the stand is unique and that part of the trees range has been shrinking due to development it is an ecological treasure. Jim Henrich has started a program that will help to ensure that this treasure is available for generations to come. Ever the Arboretum was started in 1948 very few oak seedlings have established in the Grove located on the south side of Talac Knoll. This is because the fires necessary for oak establishment, and the dominance of invasive non-native grasses, coupled with the use of string trimmers by contract maintenance crews, have combined along with a large population of seed and seedling eating ground squirrels to keep establishment of Engelmann oak seedlings to a next to nothing level. In the last two years Jim Henrich's oak establishment program has lead to an increase in survival in these seedlings which you can see if you go up to the grove on the Knoll and observe the number of chicken wire encased seedlings that are now growing there. For more information pick up a copy of the 2012 early spring edition of Pacific Horticulture in which Jim details the Arboretum's oak conservation efforts. 

Erythrina Collection

One of the hardest hit trees in the Arboretum were the coral trees, genus Erythrina. As a result it is one of the collections that will be greatly expanded here. In 1966 the city of Los Angeles made Erythrina the official city tree but did not specify a species because it was thought that between the many species of the genus that there would be a greater flexibility in cultural conditions for the many micro-climates of Los Angeles.  Already we have planted E. corraloides  in the spot where several E. crista-galli were first burned from the bad frost of two years back and then decimated by the windstorm. On Tallac knoll where frost is not much of a problem new plantings of Erythrinas including E. speciosa have been installed. 

Art from Disaster

Leigh Adams is curating an exhibit scheduled mark the anniversery of the windstorm. Over 70 artists have selected wood from storm-felled Arboretum trees and tree limbs to fashion into artworks that they will later donate back to the Arboretum for the exhibit and to raise funds through the artworks sale. 

Plumerias from Cuttings

Q. My friend wants to plant Plumerias from cuttings now by cutting them and placing them in water; can she?

A. Although now isn’t a bad time to take Plumeria cuttings, it’s just not the best; the best time is when they are just starting to leaf out in the spring. If you decide to root them now they should be about 8-12 inches in length. Make a clean cut with a sharp knife and disinfect the knife between cuts (very important) the best way is to dip the knife in grain alcohol and flame it with a propane torch until all the alcohol burns off. The second best way is to use a 10% Chlorox solution (hard on the knife; make sure you wash and DW-40 the knife before you put it away). After you make the cuttings take off all of the leaves and flower buds and store them in a cool dry place for at least two weeks to allow the cut end of the stem to heal over. This is very important if you don’t want to see your Plumeria cuttings deflate like punctured balloons after they are planted. After they are healed dip the bottom of the cutting in water and then rooting powder before planting it about 3-4 inches deep in the potting soil in 1 gallon containers (this should be cactus mix; there is also a method of using pea gravel to stabilize the cuttings shown on the first link below. Put your potted Plumerias in at least half day sun (they need heat to root). Water your Plumeria cutting only once until you see new growth, then water regularly. Check out the video, as the author talks about using dark rocks as a mulch to warm up the soil to encourage rooting.  
However, if your friend insists on placing freshly cut Plumeria shoots in water she runs a good chance of brewing a batch of rotten Plumeria tea. 

This site talks about planting the cuttings.

This video talks about the healing process and demonstrates how to root the cuttings. Also talks about using dark rock mulch and when to water the cuttings. Very good video:

Wednesday, May 2, 2012

Color In The Garden

The use of color in the garden is a powerful tool -when used correctly. Here are some links to sites and articles that discuss landscape color: 

Using color to set the mood in landscaping

Video about using a color wheel -gives you a little bit of an understanding about how colors are percieved.

The Impact of Color on Learning
This article highlights research on colors effect on learning and psychology in a school setting

Virtual color wheel that you can use on your Android tablet. Just match the color of the flowers you are considering using with this application and jot down the RGB code for that color. Later on you can use Photoshop or paint and 'paint in' the color scheme over a photograph of your garden using the codes.

Another interactive color wheel.

Proven Winners: Select from the 100's of 'Proven Winner' color annuals, biennials and perennials by color:

Saturday, April 28, 2012

Rose Show Today and Tomorrow Here at the L.A. Arboretum and Botanic Garden

Pacific Rose Society judges (l. to r.) Dwyn Robbie, Ron Feurer and Diana Kilmer discuss entrants at the April 28th, 2012 Rose Show here at the L.A. County Arboretum & Botanic Garden

Fresh-cut roses awaiting judging. 

Rose shows are fiercely competitive. Amateur rose growers take special care and patience to ensure that their entries will outshine others. However, even if you are inexperienced in the world of roses, you still have a chance to win. There is usually a novice category that is a little forgiven if you don’t yet know all the tricks and ropes. Here is a very good article that summarizes what the judges are looking for, and some pointers for winning by Robert B. Martin, Jr. from the Santa Clarita Valley Rose Society: How Roses Are Judged. The Los Angeles County Arboretum and Botanical Garden is hosting the annual Rose Show this weekend, Saturday April 28 through Sunday April 29. Stop by, enjoy and smell the roses. May be you will find some inspiration and enter in next year’s rose show!

Arboretum Rose Show and Sale Page:

Pacific Rose Society Annual Show Page:

Rose Competition Links:

How Rose Shows are Judged
This is a very good article that summarizes how rose shows are judged,
and what things rose growers who enter the competition should watch
out for.

Putting Your Best Petal Forward (pt 2): Grooming Roses for Rose Shows

Rose show is fragrant with fierce competition

Things You Need In The Garden……. To Win
By: Richard Anthony & Kristine Vance


Wednesday, April 25, 2012

Thursday, April 12, 2012

Vanilla Orchids in Tropical Greenhouse Pollinated.

Tongan vanilla rancher Hema Alatini demonstrates how to pollinate orchids. He came in this morning during the 1 hour window of time in which the orchid blooms can be pollinated.

Tuesday, April 10, 2012

An Underground Cistern for Water Harvesting at the Arboretum

When you come to GROW! a Garden Festival here the first weekend of May you will be there for the grand opening of the re-designed Garden for All Seasons. Needless to say the contractors who are installing the garden are really putting the jets on in order to get ready for the only three and some fraction weeks away grand opening. Below are pictures I took the installation of the underground reservoir for the water harvesting system. Hopefully they'll be some rain for it harvest (but really hopefully not during the weekend of 'GROW!'). This is some really cool tech here, let me explain.

This is the hole that was dug for the cistern. It's about 6 feet deep.

Here you can see the crew from Exquisite Ponds & Gardens lining the hole with PVC to waterproof the sides and bottom of the cistern.

Here you see they have placed a bunch of plastic milk-carton like structural elements. These cage-like boxes make the cistern incredibly strong and resistant to collapse. I'll show you some more progress soon! Stay tuned.
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Thursday, April 5, 2012

Plant Information Class: Field Trip to California Cactus Center

Several of the Arboretum's plant information volunteers and myself went to California Cactus Center in Pasadena for a tour. For those of you who missed it enjoy these videos I shot of the tour.

Saturday, March 31, 2012

Citrus 'Worst' Disease Detected in Hacienda Heights: Can Spinach Come to the Rescue?

Huanglongbing (HLB) early symptoms on citrus leaves. 

Huanglongbing (HLB) disease of citrus, also known as citrus greening disease, has been detected in citrus pysllids and plant material the local neighborhood of Hacienda Heights. HLB is a devastating disease that leads to the death of infected trees and can lead to the destruction of the California citrus industry (it's already destroyed over 40% of the citrus trees in Florida). It looks grim but there may be a glimmer of hope represented by a gene found in spinach by Texas A&M researchers that helps fight off the disease. Unfortunately field testing has just begun on trees modified with this gene, so it may not be available for 10-20 years. Since the disease spreads rapidly (infection in the Florida trees was only first detected in 2005) that might not be enough time to save a good portion of the industry here. However, like many plant diseases it remains to be seen if the climate difference between the humid, topical climate of Florida's citrus areas and the hot, dry climate of California's citrus areas will have any effect on the spread and severity of the disease.

Associated Press Article on HLB Discovery in California and Texas A&M Spinach HLP Resistance Gene Modification

Huanglongbing (HLB) symptoms on citrus.

California Department of Food and Agriculture HLB Press Release

Tuesday, March 27, 2012

What Do Oaks and the Irish Have in Common?

 This is a Quercus agrifolia, commonly known as a coast live oak, that was brought to my attention by a North San Gabriel Valley resident. The branches of the tree had defoliated over the last several years. The lawn is a year old, but the previous owner had grown ferns under the tree before that.

This tree is a great example of an oak that might be saved. Live oaks are notorious for defoliating under stress. You might wonder, considering the verdant and luxurious lawn that can be found under this tree, what the source of this defoliating stress is? Well consider the verdant and luxurious lawn for one...and the ferns the previous owner grew underneath the oak. Both of these require lots of water compete with the tree for nutrients. But simple competition isn't the only thing. Oomycetes (in particular Phytophtora species ) organisms that are commonly called water molds, are mostly to blame. Related to the organism that caused the Irish potato famine in the mid 19th century, these destructive organisms grow, multiply and thrive in watery environments. A well irrigated lawn is one such watery environment. The film of water that coats the soil particles in moist lawns is enough to allow the swimming spores of oomycetes to infect the roots the oak tree and cause considerable damage -as well as providing a gateway to a more destructive organism; oak root fungus. It's also a good idea to check the drainage of the area around your oak to make sure that any recent construction hasn't created an impairment for the runoff of water from the area.

So what can be done? The first thing is to tear out the lawn underneath the canopy (or the area that would have been the canopy if the tree wasn't defoliated) and mulch the area with shredded bark. Then allow the trees own leaves to build up in a thick layer underneath the tree. If recent construction has impaired water runof, fix it so that water drains away from the area where the oak is planted. Then treat the area with Agrifos according to instructions (Agrifos is a type of fertilizer that has a preventative action against oomycetes). And finally adjust your watering so that you are not watering the tree; natural rainfall is usually enough to sustain the tree. However, additional watering may be necessary in situations where it is a drought year and the original water gathering root area of the tree (which can be an area up to twice the diameter of the tree's healthy canopy) is compromised.

Here is a particulalry good publication that goes over what can go wrong with oak trees.
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Saturday, March 24, 2012

Carried Away

 It's hard not to get that here when it comes to photography.
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Friday, March 23, 2012

Is This An Oak Defoliation Culprit?

Chaperral camel cricket; responsible for a naked oak tree?
  I received a picture of this guy in my email a week back from a local oak tree owner who was finding them on her now defoliated oak tree. Was this one of the infamous 'Gold Spotted Borers' whose occurrence here could spell doom for thousands of our Oak trees? Well, probably not as evidenced by this creatures large hind legs; do they look familiar? Yes, it does look like a cricket and, according to L.A. County Agricultural Commissioner's office entomologist Gavork Arakelian this is a native cricket known as the 'Southern California chaparral camel cricket'. It does eat leaves, but whether it's responsible for defoliating an entire oak tree is questionable. There are other insects that can cause defoliation including the California Oakworm, but many of those are summer pests and are inactive in the spring. Still, a closely related insect in Texas has been known to defoliate oak trees. So is this the culprit? Although I don't have enough information it is possible but not likely  because the Chaparral cricket is omnivorous, it will eat anything,  including oak leaves.
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