Well over half of the human population is sensitive to poison ivy, poison oak or poison sumac. Rashes usually peak in early summer, and tens of thousands of people in the United States go to the ...

Many coast live oak (Quercus agrifolia) trees are showing unusual browning in their canopies in the last month or two. If you look carefully, you may see small, crescent-shaped galls forming on the ...

Purdue Landscape Report: Each spring the PPDL receives several samples of oak trees showing curled, twisted, stunted and/or generally ratty looking leaves. When there are holes in the leaves or leaf ...

Poison ivy has three leaves, and the middle leaf has a longer stem. Touching poison ivy causes an allergic reaction due to urushiol oil. Poison oak and poison sumac are related to poison ivy and also ...

An average mature oak tree grows hundreds of thousands of leaves each year. When those leaves fall, their nutrients return to the soil to nourish the tree that grew them, as well as other living ...