Since they are evergreen, many people do not realize that pines are always producing new foliage. The needles of ponderosa pine remain on the twig for 2-3 years before they are shed. Each year, the tree produces new foliage from buds formed the previous year. These buds contain all the needles that will be formed that season. In spring, the tiny needles begin to grow inside the bud, and expand like those shown here. These elongating buds are often called "candles" because of their shape. These candles may grow to several inches in length before they burst open, exposing the new needles.