Liquidambar styraciflua

Here is a beautiful tree on Piedmont St, near Asbury, in San Francisco. This American Sweetgum is technically a deciduous tree, but here in our Mediterranean climate they don’t normally lose all of their leaves at once. They look a lot like Maple trees. Some of them have better fall color than others.

We needed to prune this tree for clearances and to reduce the weigh on the ends of the branches to reduce the risk of a branch breaking and causing damage. The goal was to make the tree look as natural as possible.
Before pruning:

After pruning:


I don’t know who pruned this tree, but it looks terrible. Is it really worth saving a couple of hundred dollars for this?

Some trees grow on granite

Check out this Juniper growing out of a granite boulder at Yosemite National Park.  Thousands of years of evolution has enabled this species to grow in this environment, high on a mountain, perched on a granite boulder.  It wouldn’t survive anywhere but here.

California coast Redwoods need moist, temperate air, humos rich soil.  They naturally grow in valleys.  They don’t like wind.  Yet, people love them and want to plant them in windy San Francisco and in the dry central valley.  So they look okay for ten, twenty years.  But they they turn brown.  And they call me.  And I have to tell them it probably shouldn’t have been planted in the first place.

Sycamores are riparian trees, but require a drier climate. They hate wind.  Yet we continue to plant them all over San Francisco.  Why?  Who knows?  They look terrible in Civic Center; thin, barely any foliage, leaning away from the wind.  They keep planting them on Valencia.  It’s too bad.  

Jacarandas, from Brazil, need lots and lots of sun. They look great in Mexico City.  Flying in to the city in March, the ground is blanketed in purple.  In San Francisco they generally look sick.  Some years are better than others.  Sometimes they bloom well, sometimes not.  This is not a tree I would plant here.

So before you choose a tree for your desired location, consider your soil type, the wind, water availability, and sun exposure.  Sometimes the recipe for a successful planting can come down to being on the sunny side of the street or away from a wind tunnel.  

Ficus Forest

These big Ficus Trees on Carolina and 19th Street in San Francisco were getting too close to the high voltage power lines. It took 5 of us 4 days to prune all these trees. The goal was three fold: First we wanted to keep PG&E out of the picture. PG&E tends to do a really bad job pruning trees. They are certainly cheaper, but you get what you pay for. Secondly, we needed to create a 14 foot clearance over the street to comply with the city regulations and to keep trucks from damaging the trees. Finally, the clients wanted to let more light onto the sidewalk. Sometimes a dense canopy can lead to mischievous behavior at night. The neighbors wanted to feel safer.
Below is a BEFORE picture.

Here is an AFTER picture:

Here is a picture of BEFORE and AFTER in one:

Make way for new a new cross light in Atherton

About a month ago I sprained my ankle. It was inconvenient, but I was still able to work from this bucket truck. It’s a wheel chair for arborists. I wouldn’t recommend this for fine pruning, but for street clearances I was able to get the job done in record time. The electric company provided the truck. It was fun. But I had spiders in my bucket, eek!

Maytenus boaria, Mayten Tree

The Mayten Tree is a beautiful tree from Chile. It has a gorgeous pendulous branching that looks like a waterfall. BEWARE!!! Although this tree looks spectacular it has the most aggressive suckering roots that I have ever come across in San Francisco. If you plant it in your garden you will have suckers popping up all over the place, possibly in your basement. Also, if you prune this tree too aggressively it will sprout back even more aggressively. So prune lightly; make fewer, larger cuts. Be prepared to have to prune often to keep the desired shape.

Pictured below is a street tree that I pruned in the Castro Dist. As you can see it looks a bit unkempt. I cleaned it up and also planted some succulents in the tree well.


Tree of the Week, Magnolia grandiflora

*Botanical Name: Magnolia grandiflora (grandi means big and
flora means flower, just in case it wasn’t obvious enough).

**Family: Magnoliaceae

***Common name: Southern magnolia (most common in SF), bull- bay, evergreen magnolia.

****Native environment: Virginia to central Florida, Arkansas to Eastern Texas (left).

*****Height: up to 90 feet. Wiki says the biggest ones recorded are in Louisiana; one tree has a trunk18 feet in circumference at breast height; another tree is 114 feet tall. Wow!!

******Likes rich, moist, well drained soil. They do NOT do well if the soil constantly wet. They can tolerate shade when they are younger, but need full sun later on in life.

*******Many cultivars; some with gigantic flowers (up to a foot across), some slow growing dwarf trees, various leaf sizes, colors, and shapes. My friend Waiyde says he has one that has huge, dark purple flowers.

*******Magnolia grandiflora is an evergreen, but they still drop leaves and make a mess. The last time I pruned a magnolia street tree this little old man kept telling me to cut it down completely. He groaned and groaned about it so much we nick-named him “Mona”. He said he was forever having to sweep the sidewalk. Poor Mona; not a very happy man.

Southern magnolias are very common in San Francisco as street trees. They have large, waxy, dark green leaves that are sometimes yellow/orange and fuzzy underneath. The waxiness make them very tolerant of pollution in cities. The big, usually white blooms are quite fragrant. Yum.
It is also the state flower of Mississippi and Louisiana and was an emblem of the Confederate army in the Civil War.
It is also Mississippi’s state tree.

Here are a couple of small magnolias we pruned over on Vicksburg in Noe Valley. I did the pruning, Kent did the ground work. Kent is great at securing the ground, making sure that I am aware of pedestrians walking below. We don’t want anyone getting hurt.

before: after:

Little Metrosideros in the Sunset

Here is what a tree looks like a few years after it’s been badly topped.

It looks like a bit like a shrub on a trunk (right).

Well, we trimmed this poor little tree the best we could. This will be a process of restoration that make take several years (above).
We also planted the tree well with succulents and filled it in with decomposed granite. The bank manager, Rosemarie, was really happy with the outcome. I love planting tree wells.

Black Acacia

The goal for pruning this tree was crown reduction.

Judy had wanted to plant an Acacia baileyana (Bailey acacia), but she ended up with an Acacia melanoxylon (black acacia). Oops. These are two very different trees. Judy had wanted a small tree…

The baily acacia is fast growing and relatively short lived (20-30 years). They have feathery leaves and grow only 20-30 feet.

Leaves and flowers of the baily acacia (below). There is also a variety called purpurea, with purple leaves.

The flowers of the trees in the genus acacia are usually little yellow puff balls (left). Many people in SF complain about their allergies to the pollen. They create a big mess as well…

Acacia bailiana is a very pretty tree for the first 10 years or so. Afterwards they become a bit rough looking. The branches die back strangely so that there are lots of right angles, making them look like a bit like a fuzzy tumbleweed.

The black acacia leaf is lanceolate, meaning long and narrow, but wider in the middle (below).

They also grow very fast and very tall. This is not the tree to plant if you have electric wires overhead, or if you are Judy and you simply want a small tree. The bigger ones here in San Francisco are around 50 feet. In the wild they can get to be as big as 150 feet tall.

I love pruning these trees because they can be made to look spectacular through natural layering. They can look like big, puffy, green clouds.

Judy wanted us to reduce the size of her tree since she didn’t want a large tree in front of her house. We reduced it as much as possible without making topping cuts. She would have liked to have been brought down further, but that would have been bad or the tree.

In order to keep the costs down we kept the design element to a minimum. We worked strictly on crown reduction, not layering.

Here is an after shot of Judy’s tree. As you can see, we successfully reduced the crown while also giving the tree a nice shape.

Kent did the ground work and I did the pruning. Kent’s job is also to occasionally give me an “eyeball.” It’s difficult to see the overall shape of the tree when I am inside the canopy. Kent can tell me if he sees anything sticking out that disrupts the line. He can also assure me that I am finished. Kent studied art in school and he has a good eye for detail.

I’ve been studying the acacia tree as I’m here blogging away. It’s a very complicated tree.

Family: Leguminosae. That is the pea, legume, or the bean family. The third largest family of flowering plants behind Orchidaceae and Asteraceae. 730 genera, 19,400 species.

The word acacia is derived from the word akakia, which is the name given by a Greek botanist. The name is derived from the Greek word akis means thorn.

The following is ripped off from Wikipedia:

“Acacias are also known as thorntrees, whistling thorns or wattles, including the yellow-fever acacia and umbrella acacias. Until 2005, there were thought to be roughly 1300 species of acacia worldwide, about 960 of them native to Austraila, with the remainder spread around the tropical to warm-temperate regions of both hemispheres, including Europe, Africa, southern Asia, and the Americas. However, the genus was then divided into five, with the name Acacia retained for the Australian species, and most of the species outside Australia divided into Vachellia an Senegalia.”

That’s enough for now. Soon it will be Tree of the Week and I’ll ply you with more.

Too big for its pot

I was called out to trim a large, 30 year old Pittosporum undulatum. From below I could see that there was some disease.

When I climbed into the canopy I found out that the disease was much worse than it seemed.
There was die back along the main branches. There were also mushrooms. Mushrooms in trees is a sign of rot on the inside of the tree.
The reason why is that this tree got too big for the pot in which it was planted. 30 years ago it was just a little tree. Today, it is massive.
We didn’t want to remove the tree right away. A most trees do, it has a lot of sentimental value (as well as aesthetic). Laura planted it herself 30 years ago when it was just a tiny sapling; when it was the only tree on the block. She had no idea that it would become so large. The tree will have to come down some day. We’ll keep an eye on it for now. Fortunately Laura also planted a sidewalk tree so that the space won’t be completely bare when the Pitto is gone.
These Pittosporums are very stubborn trees. They can take a lot of abuse, but we don’t want to risk a branch falling on a pedestrian on thesidewalk. So we removed some major limbs, reduced the weight of the diseased branches and made a commitment to monitor the disease over the next few years.
We also pruned a New Zealand Christmas Tree that was in the sidewalk. I did the pruning and Kent took care of the ground work. Here are some before and after photos: