I first heard about the sissoo tree this week from my real estate client who lives in Stetson Valley.
The association management company there recently uprooted over 100 healthy sissoo (also known as “Shisham”) trees from areas between the sidewalks and curbs in this Pulte neighborhood in the northwest Valley. The removal and replacement cost estimates exceeded $30,000 and the trees had only been in the ground for 10 years. This made me curious.
Scanning some online gardening and landscaping forums, it became apparent that this tree has a polarized following. Some Arizona homeowners appreciate the tree for its first-rate shade or curse it for its destructive and invasive thirsty root system.
The Dalbergia sissoo or North Indian rosewood, is not native to the Sonoran Desert. The origins of this semi-evergreen tree are in the Indian Subcontinent, southern Iran and Nepal, but it fits comfortably within the parameters of our Arizona climate: it is drought-resistant, hearty in poor desert soils, loves direct sunlight and it can tolerate a light frost.
Visually, it is a captivating tree that resembles an aspen. It’s opaque, dense, dark green crown stands out against other native desert-dwelling trees which are known for their wispy, transparent and low canopies, like the palo verde. Its shade qualities are immediately apparent. The twisting lower trunk of the sissoo features a light brown shag bark, which is largely absent on higher lateral branches. Tapered oval leaves alternate sides of the stem, are deep green in color, about the size of a half-dollar and are leathery to the touch.
It will drink plenty of water, but it doesn’t depend on homeowners to irrigate it. The serpentine root system can run for 40 feet or more from the base of the tree and wrist-sized roots can break through just at the surface over the distance. Finding water is its specialty. It made its home along river banks in India.
It is popular with residential developers and builders here in the Grand Canyon state because it grows quickly, reliably and provides thick shade from the sun in a few short years. Sissoo has also been planted in city parks in both Phoenix and Glendale.
Dalbergia sissoo can grow rapidly up to 60 feet in height and up to 25 feet in width in the desert climate. An eight-year-old tree can be 18 feet tall.
Here’s the rub. Once developers and builders move away, homeowners and their associations are left to deal with the sissoo. This can be problematic, especially if the tree’s space needs and aggressive growth ability were not calculated with consideration at the time of planting.
Most of the online complaints that I read tended to come from homeowners who planted (or inherited) the sissoo tree too close to a home foundation, concrete block wall, sidewalk, irrigation lines or a pool. These trees require a large berth and should be kept 50+ feet away from foundations or structures that would be targeted by the sissoo’s shallow-running root system.
I suspect that this is precisely why they were removed from the Stetson Valley neighborhood curbside locations.
Anecdotally, a lot of sissoo trees are coming out of the ground in Arizona. An employee of a local Phoenix nursery shared with me that 90% of his removal jobs are for sissoo trees.
The three-inch seedpods that are left by the sissoo can be burdensome, too. One online gardening forum poster claimed that it is a “messy tree year-round“ and sends roots abroad even after the tree trunk has been cut down.
In order to kill the roots of the removed tree, they need to be painted with an herbicide. The trunk of the tree should be ground down with a stump grinder.
The key to happiness with the Dalbergia sissoo? It helps to have a big yard. Plant it far away from structures and in an area of your property that does not require ground grooming or maintenance. If the tree becomes large enough, you will be rewarded with some rich, reddish, cedar-like wood that has been featured in Asian furniture and musical instruments. It is the second-most cultivated wood in India, next to teak.
Keep your eyes open for the Dalbergia sissoo during your home inspection, especially if you are buying a home in a newer subdivision. If found, note the tree’s location near structures and look for surface roots.
The Arizona Standards of Practice for Home Inspectors requires only that inspectors observe vegetation “with respect to (its) effect on the condition of the building.” In other words, an inspector would not normally report a sissoo if its roots or branches did not visibly threaten the house.
What has been your experience with the Sissoo tree in Arizona? Leave your comments below.
Someone is sitting in the shade today because someone planted a tree a long time ago. – Warren Buffet, legendary American investor and philanthropist