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.