A Rant On Liquidambars

 Our recent breezy weather is bringing out lots of concern about the safety of trees planted next to houses. I recently had an inquiry regarding one tree that should never be planted near houses or any hard-scaping for that matter...and it's not a Ficus.

Liquidambar styraciflua is a tree native to parts of the Southeast United States, Mexico and parts of Central America. It’s called a ‘Sweet Gum’ because Native Americans would chew the tree’s resin like chewing gum.  The tree is not at home here in dry Southern California. Where it's native the precipitation averages 25-35 inches of rain a year. The problem is that it is also a tree that has evolved to survive in rocky, infertile soil in its native range.  This ability to ‘tough out’ those harsh conditions makes it appear to be the perfect tree for Southern California; nothing is further from the truth. With the dry winds and the infrequent precipitation Liquidambars here are constantly under water stress.  They also have the propensity to develop very invasive and destructive roots.  But wait there’s more. Ever since 1998 when a new pest called the ‘glassy winged sharpshooter’ was introduced to California Liquidambars have been infected with a disease called ‘scorch’.  First appearing on Oleanders, this disease is a bacteria that plugs up the water conducting tissues of the plants it infects and causes the shoots furthest from roots to dry out so fast they literally ‘scorch’ where they stand.  This has gotten so bad in parts of Riverside county that it causes the trees to die back to almost 2/3 of their former height, causing them to look disfigured and leading to their removal for aesthetic reasons.

Now also consider that the  chances of damage from the wind toppling Liquidambar  trees is  probably not as great as the chances that the trees roots will damage some structure that the tree is within 10-25 feet of. 

So all this leads me to my final opinion on yours, and every other Liquidambar tree growing in Southern California. Unless your tree is at least 25 feet away from any structure it can damage with its invasive roots, and is surrounded by a lawn (which is the only way it’s going to get sufficient water to remain healthy and tolerate the effects of the scorch disease) I would remove the trees and plant something else.

Links:

Here's an article I wrote two years ago about Liquidambars

Australian Garden Expert Don Burke's List of Trees to Avoid; This Advice Good for Southern California Too

Scorch damage on a Liquidambar leaf

Aquamog Returns to the Arboretum

This whimsical machine is going to clean out all the debris that the winds knocked into the Baldwin lagoon!

The L.A. County Department of Parks & Recreation tree crew guide the large central trunk of a hazerdous tree being removed from behind the Arboretum gift shop.

Work continues on cleaning up the wind mess here at the Arboretum. In this picture tree crews are removing toppled limbs from a large Ficus tree located on the south part of Tallac Knoll. 

Should She Remove A Wind-bent Fan Palm?

Spent most  of the day working on a new GIS system that will allow us to map the 326 lost trees in less than a weeks time -a real improvement over the 5 year mapping cycle that is the norm for our 14,000+ collection. Tomorrow the system gets a field check.

I had a call today from a Pasadena resident who noticed after the wind storm that her neighbors tall Mexican fan palm has a noticeable lean of almost 45 degrees. This is not necessarily a death sentence, as evidenced by the existence of many 45 degree leaning palms on the Arboretum grounds. There was, sometime in the late 1880's a horrific windstorm that blasted the San Gabriel valley, maybe the Arboretum's leaning palms were the result of this storm? At any rate since palms are so resilient you might say what doesn't kill them makes them stronger. Since she related that if the palm failed there would be no great consequence I suggested she enjoy her per-quaky palm.

Queen Anne Cottage (pre-windstorm) showing leaning, but stable Mexican fan palms. 

Nature and Beauty Don't Seem to Care About the Winds

Egret stands in small stream in Meadowbrook section. 

It's Sunday here at the Arboretum and the windstorm chaos of a week ago almost seems a thing of the past; except for all the branches and debris. Walking through the Arboretum I'm amazed how nature continues its sublime production despite the blow it's both received and dealt.

Japanese maple blazes a brilliant autumn red while in the background Arboretum staffer Glen Klevdal cuts  wind-felled branches in preparation for their removal.

The progress being made here since the 'Mighty Wind' has been heartening. We have several tree crews from different county organizations working on the clean up including County Fire Department camps 2 and 9 and the L.A. County Dep. of Parks and Recreation's tree crew.

Starting to Get Back To Normal

After days of slogging through the debris covered cataloging and evaluating trees with senior biologist Jim Henrich some normalcy has occurred; I was able to give my monthly plant information class hold a small holiday party for my volunteers. At first it didn't look like it would happen. The damage looked so great here that it was thought that the Arboretum would be closed for months. That is not the case now, thanks to the efforts of a lot of different people in the county. Today we had crews from trail maintenance, county fire, and several others chain-sawing downed trees, cleaning up debris, and chipping limbs. Add to that the support and calls to offer assistance, and the press coverage of what has happened here, I never thought I'd be so hopeful as I am now...incredible progress is being made.

County Fire Camp 2 and 9 crews helping with the cleanup here at the Arboretum. 

Richard Schulhof and Tim Phillips Describing Wind Damage at the Arboretum

This is a link to a video interview of Arboretum director Richard Schulhof and Tim Phillips talking about the damage done by the hurricane force winds here. It was done by the Web Newspaper 'Arcadia's Best'. What's really interesting is that Tim Phillips has had experience as a supervisor at a botanic garden in the Caribbean that was struck by a hurricane; hear how he compares the damage between the that experience and Friday morning's devastating winds here.

The WInds

Last nights winds sounded like a jet engine parked next door and left on full power. I stayed inside my place,  but when I did look out all could see were all the trees in the neighborhood doing a crazy, insane dance; diving and bending at angles I didn't think possible for any living thing. I live a few blocks from the Arboretum so I was not looking forward to going to work.

I walked up Baldwin to the Arboretum and saw branches and uprooted trees everywhere, and then I arrived at the Arboretum.

I was heartbroken by the shear magnitude of the devastation; hundreds of trees damaged or lost. I took some pictures so you can get an idea of how much of a hit the Arboretum has taken.  Now I know that some of these trees might recover, and that these kind of winds are a normal, if not a very frequent, occurrence here (this noted by the low number of native oaks we lost); but it's still sad to think some old friends out there in the Arboretum are lost forever. Enough blog writing, time to help my coworkers clear some debris.

Will This Be the Last Fall Color Blast?

Winds of 60 to 70 miles per hour are predicted tonight for the L.A. Basin and outlying areas; will these winds visit the normally wind-sheltered area underneath the San Gabriel mountains where the L.A. County Arboretum & Botanic Garden is located? Stay tuned...until then here are some pictures I took just today and yesterday; they may be the last pictures of fall color here before the wind blows all the leaves off of the trees.  BTW, check out the huge flowering Dahlia imperialis located in the Garden for All Seasons
11/30/2011

11/29/2009


For more on Fall color around the state, check out http://www.californiafallcolor.com

More Fall Color Shots

Out and about on the grounds and the show goes on; the Fall color is still amazing!

By The L.A. River

Went down to the river today to look at plants for a filmmaker/artist doing a piece on the origins of the plants that find there way into the river bed and found some interesting stuff. One of the more interesting sights were a group of egg-like mushrooms growing in a sandbar right there in the river. I took them back to the office and identified them as Phallus impudicus, the Stinkhorn mushroom. This mushroom usually grows on under-composted wood mulch but here it was growing on the roots of a recently killed Arundo donax plants. Here's a video of Phallus impudicus fruiting in time-lapse. ( Warning: Not for the Faint of Heart or Easily Disgusted ).   

I'll go over some of the other interesting stuff in my next post.

Another Fall Color Report

More Fall Color

For kids with ADHD, regular 'green time' is linked to milder symptoms

For kids with ADHD, regular 'green time' is linked to milder symptoms

If you've ever noticed your kids seem to behave better when you take them to the Arboretum, well here's a scientific study that backs you up!

Fall Color Report 11/12/2011

Album with map locations here: https://picasaweb.google.com/botaknee/FallColorReport11122011?authuser=0&feat=directlink

More Fall Color

Arboretum Fall Color 11-9-2011

This album includes a map that shows the locations of the subject trees.

Looks Like Fall Color is Ramping Up

I was out on the grounds this last Sunday and the Fall color is starting to look good. Keep your fingers crossed that we don't have any hot, windy Santa Ana winds or heavy, driving rain. Here's some of the pix I took while I was out on the grounds:

Plants that Peacocks Pass

Every two months here in peacock graced (or infested depending on your opinion ) Arcadia I get inquiries about what plants they will not eat. First off, peacocks will dig up newly planted small container plants just to get at the grubs and insects that the newly transplanted plant's injured roots attract; second peacocks like the new foliage of plants they may not necessarily feed on once the foliage has matures. The best thing to do with flowers is to establish them in area that has been surrounded by bird netting. If you can't do that then try using a motion detecting scarecrow to do the job; but be careful, I once almost gave a UPS delivery man a heart attack when my motion detecting scarecrow went off without warning and scared the daylights out of him.
Here is a list that has been compiled over time here at the Arboretum of plants that are resistant to peacocks.
Agapanthus
Azalea
Baby’s Breath
Bee Balm
Bird of Paradise
Blazing Star Liatris
Bougainvillea
Butterfly Plant
Cactus
Camellia
Cannas
Clivia
Columbine
Coneflower
Ferns
Fuchsia
Gaillardia
Gardenia
Geranium
Giant Columbine
Gladiola
Gloriosa Daisy
Hen & Chicken
Hibiscus
Hardy Lavender
Hostas
Iceland Poppies
Iris
Ivy
Lantana
Lavender
Marigold
Mint
Mum
Oleander
Painted Daisy
Periwinkle
Peonies
Phlox
Pink Lady
Plumbago
Poinsettia
Pyracantha
Rhododendron
Rose
Shasta Daisy
Snap Dragon
Sunburst Coreopsis
Weigela

Super Soperific Sapote

A volunteer brought in a green fruit he found on the grounds today and wanted to know what it was; turns out it's citrus family member white sapote, Casimiroa edulis. I did a little research on the fruit and found that it's considered soporific, in other words, a sedative; surprisingly one of the ingredients responsible for this effect is a compound that mimics histamine, the chemical messenger that tells our body to swell up in response to bee stings and pollen.


California Rare Fruit Grower's white sapote page :

http://www.crfg.org/pubs/ff/whitesapote.html

Purdue Horticulture Department's white sapote page:

http://www.hort.purdue.edu/newcrop/morton/white_sapote.html