Polyphagous Shot Hole Borer and Avocados

Multiple entry holes on avocado trunk. Photo credit: Eskalen Lab, UC Riverside.

Multiple entry holes on avocado trunk. Photo credit: Eskalen Lab, UC Riverside.

Of all the plants in our yard the one I care most about is our avocado tree. I’d be despondent if anything happened to it. Which is why I panicked when I first heard about the Polyphagous Shot Hole Borer (PSHB), a beetle that spreads a fungus Fusarium euwallacea. First noticed in 2003 here in Southern California, the PSHB seems to damage some trees more than others.

Concerned about losing my avocado tree I wrote Akif Eskalen, a plant pathologist at the University of California, Riverside. Dr/ Eskalen’s lab has done a lot of work on the PSHB and what to do about it. I asked him specifically about avocados and here’s what he had to say in an email,

My lab has been conducting a continuous survey on PSHB on infested and non-infested avocados in California since 2012. Based on the preliminary results from our survey the beetle PSHB seems to be attacking and causing damages on primary and secondary branches of avocado only. We have also seen attacks on the trunk of the trees but somehow the beetle is not successful establishing galleries there which could cause of quick death of the tree. I believe with a proper orchard sanitation you can reduce the damage of the beetle and also keep the beetle population down in the orchard . . . we are still continuing experiments with different insecticide and fungicides on avocado against this beetle and their fungi. An insecticide (Hero) has already registered under Section 18 that could be used by growers in CA.

He provided a link to a short publication his lab put out on orchard sanitation best practices as well as a link to information for avocado growers on the use of Hero. Hero is a pyrethroid-based pesticide.

For my own backyard tree I’m going to:

  • Make sure pruning tools are disinfected before use. This is one of the main reasons we use a qualified arborist.
  • Avoid moving firewood around. I’m going to have to think carefully about the wood I import for my pizza oven.
  • Use mulch that has been chipped to less than 1 inch.

I’d sure hate to lose a tree that provides six months worth of free and delicious Fuerte avocados.

A Cheap and Easy DIY Sewing Cutting Table

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Kelly, tired of hunching over the floor while she works on sewing her uniform, asked me to make a cutting table for her tiny sewing room, which is located in a vintage 1920s shed in our backyard. Using the Garden Fork TV ethos, “done is better than perfect,” plus a time limit of one day, I set to the task.

Cutting table dimensions
A cutting table should be just a bit lower than your palm when your elbow is bent at 90 degrees. Architectural Graphics Standards suggests that work tables be in the 36-inch to 38-inch range. My parents met in a club for tall people and Kelly’s dad played basketball in college which means that work table height around our compound needs to be higher. I ended up going with 36 inches, since that’s the size of the bathroom cabinets I scavenged for the project. I may end up raising the table, at some point, when I’m in less of a hurry to get things done.

Opinions about width and length for cutting tables vary in the sewing community. At minimum, a cutting table should be at least 3 feet by 6 feet. Slightly wider and longer would be better but there’s not enough room in Kelly’s 10 by 12-foot shed.

cheapandeasyMaking a cheap and easy work table
When I built my workshop I discovered a formula for creating work surfaces. I used a similar process to make the cutting table.

Step one: go to the Habitat for Humanity ReStore or ReUse People of America and find two or more matching kitchen or bathroom cabinets.

Step two: get a sheet of melamine at the big orange store.

Step three: cut the sheet of melamine to size. To do that I bought a plywood blade for my circular saw (I don’t own a table saw). I clamped a scrap of plywood to the board as a guide and ran piece of masking tape along where the cut to prevent chipping. You could also get the lumber yard to do this for you.

Step four: attach the melamine to the cabinets with screws.

Step five: Apply iron-on edging tape to the melamine to cover the edges.

Step six: Pop open a beverage of your choice and call it a day.

Look closely and you’ll see that Kelly’s cutting table also accommodates 20 gallons of emergency water since that’s how she rolls.

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Saturday Tweets: Bee Stings and Doughnuts

Attractive Ornamental Flowering Trees

As I mentioned yesterday, I attended a class a tree identification class at the Arboretum taught by LA County plant pathologist Dr. Jerrold Turney. During the course of the lecture Dr. Turney recommended a number of striking, flowering ornamental trees. I thought I’d list a few of those remarkable trees in case you’re considering planting one. While this list is Southern California-centric, many of these trees can be grown in other climates. All images are courtesy of Wikimedia.

800px-magnolia_stellata_in_the_jardin_de_plantes_de_paris_001Magnolia stellata (Star Magnolia)
Small trees go with small houses like gin goes with tonic water. Small trees are also easy to maintain and don’t break the bank when it comes time to call an arborist. This tree is from Japan and will grow all over North America and Europe.

754px-cornus_florida_02_by_line1Cornus florida (flowering dogwood)
One catch with this pretty tree is that it’s susceptible to anthracnose.

800px-ipe%cc%82_roxo_ype-tabebuia_impetiginosa_cemiterio_sa%cc%83o_paulo_brazilTabebuia impetiginosa (pink trumpet tree)
A tough and beautiful tree that’s great for urban locations.

tabebuia-chrysotricha

Tabebuia chrysotricha
Of all the trees Dr. Turney showed, I think this one was my favorite. The yellow flowers really pop out against a blue sky.

848px-illawarra_flame_tree_brachychiton_acerifolius

Brachychiton acerifolius (Australian Flame Tree)
Speaking of popping out, red flowers are also really dramatic.

chionanthus_retusus_-_chinese_fringetree_-_3Chionanthus retusus
Another good urban tree.

To these suggestions I’d add one of my own that also produces a tasty fruit:

redbaronRed Baron Peach
Plant one of these as a bare root tree this spring and you’ll have an attractive small tree and peaches!

Thanks to Dr. Turney for a great lecture. If you’d like to attend the other three parts of his tree identification class you can sign up here.