First . . . the data. Mistletoe is the common name for a parasitic plant with yellowish flowers and glutinous white berries that grow attached to, and within, the vascular system of a tree or shrub. Mistletoe does not normally kill a tree,...

Lion’s tailing is the “gutting??? of a tree by removing a large number of the inner branches. The limbs of the tree look like a lion’s tail after pruning. The limbs will appear “long and slender??? with a “puff??? of foliage at the end, like...

How to Solve Storm Runoff While Staying Green

Storm drains in the San Francisco area discharge directly into San Francisco Bay, thereby allowing the water to carry surface debris and chemical pollutants with it. These pollutants destroy local...

People love superlatives. 

We want to know which car is fastest, which athlete is strongest or which CEO is the richest, even though the results have very little bearing on our lives. And of course, who can forget the superlatives section...

Many parents seek to educate their children about the natural world and our place in it. While one could argue that virtually any aspect of the natural world – from beetles to mushrooms to plankton – can serve as a good starting point, we are...

Recently, we posted a quiz designed to test the tree knowledge of the general public, but, today, we wanted to share a similar quiz. However, we made this quiz for tree-care professionals (who should have aced Monday’s quiz). Scroll down to...

Are you interested in testing your tree-teligence? Take our tree-knowledge quiz below and see how you do! 

Each question is multiple choice; scroll down for the answers. We designed this quiz for laypersons, but we have published a quiz...

While not terribly common, many trees bear sharp thorns along their twigs, branches or trunks. Often, thorns are seen as problematic traits, and trees that bear them are often avoided during installations. Some have even produced thornless...

Every day, our collective understanding of trees improves. In addition to learning more about the behind-the-scenes world of trees, we learn new ways to battle pests and control the spread of invasive species. Today, we wanted to share a few...

A few weeks ago, you noticed that the big sycamore tree (Platanus racemosa) in your yard developed a large vertical crack. 

You did the right thing, and immediately called an ISA-certified arborist to evaluate the tree. Unfortunately, the...