"I heard a van pull up and looked out and saw two people get out with a tree trimmer and walk toward the property," he said on Wednesday. "They had a piece of the tree in their hand and said, 'Would you mind if we cut a few branches?'
"I said I would mind, and I asked them to leave," he said of the April 12, 11 a.m. attack on his front-yard tree. "The dogwood is in full bloom, so maybe they were stealing it to sell to florists. Who knows?"
O'Sullivan is not alone. Throughout the Bay Area at this time of year, gorgeously flowering trees become cash cows for some thieves. They often come with pruning saws and shears in the middle of the night, police said. The bundles of branches can fetch a good price. Harvesting from one tree can net as much as $150, said Bill Zappettini, whose family has been in the flower business at the San Francisco Wholesale Flower Mart since 1921.
Zappettini said a bundle of branches can cost as much as $50 wholesale, depending on quality and size. Dogwoods produce showy "flowers" — actually flower bracts (modified leaves) that surround the tiny greenish-yellow flowers. They look like four fleshy petals in white or pink. The blooms measure about 2 inches in diameter. They are much sought after because they are long lasting, Zappettini said.
Florists use the branches as filler in bouquets and as decoration. But there is a short season, which lasts just a few weeks in spring.
Palo Alto police said the tree-branch thefts come in waves. Sgt. Ken Kratt recalled many dogwood-branch thefts in 2000 and 2001 but said he had not heard of that type of pilfering again until now. Sgt. Sal Madrigal said the thefts of flowering cherry and dogwood pop up from time to time.
The demand for dogwood isn't new.
Fifty years ago, there were never enough blooms to meet demand, Zappettini said. In the 1970s, as the market flourished, professional gardeners asked if they could prune dogwoods in people's yards.
"They became very popular, and then they started to ship all over the place," he said.
The market took off in the 1980s. To meet demand, growers started putting in dogwood farms in places such as Petaluma and in Oregon, Zappettini said.
But apparently some people prefer making some quick bucks hacking trees in the middle of the night.
Palo Altan John Hanna said the problem was so bad at one point that he and his neighbors added motion-sensor lights. One person added trip wires. Hanna and his neighbors even hired a security guard to patrol their blocks for a week, he said.
"The people who do this are ruthless," he said, noting he had a beautiful dogwood that was attacked at his former home in the 1400 block of Hamilton.
"People need to be vigilant when their dogwood is blooming. It really needs some kind of neighborhood watch."
Hanna said his azaleas have been routinely targeted, and some thieves also go after hydrangeas, which have large, beautiful blooms. One resident suggested painting the branches in a way that could identify them if they are stolen, he said.
Zappettini said most residents probably don't realize there is a value to many materials routinely pruned from their gardens. Most probably would just take the cuttings to the dump. But dried manzanita, acacia, tree of heaven and mock orange are popular for fillers among flower bouquets and are often shipped to the East Coast, he said.
Jesus Palafox, owner of JP Evergreen at the flower mart, said variegated pittosporum and eucalyptus are two other favored fillers among florists. He sells dogwood bundles for $10 wholesale, depending on the size, he said.
Many branch sellers who approach him often don't know what they are doing, he said. "People have to know how to cut it. It's too late when the flowers are already open for a florist to use it," he said.
Zappettini said cutting back a dogwood to make $150 is highly damaging.
"The tree's gone, it's cut to nothing," he said.
City Arborist Dave Dockter said pruning trees in the spring is not generally a good idea. Springtime is when most trees are putting out new growth, flowering and setting fruit.
Every cut causes the tree to expend energy to seal over the wound. Some thin-barked trees such as fruitless mulberry have difficulty controlling sap bleeding, he said.
Cherry trees, another popular flowering tree for thieves, is a worse bleeder than dogwood, he said. But dogwood is a slower grower and is slower to respond to wounds and to callus over. The cuts leave a tree vulnerable to fungus and disease, he said.
O'Sullivan has set up a motion-detecting camera to protect his property.
"I look at this as similar to copper theft. It's kind of the same thing. They are stealing valuable landscaping. It really needs to be addressed.
"I was surprised at how brazen they were. They looked like landscapers and wouldn't be questioned," he said.