The changing of the leaves in Squamish this year is beautiful. Our wet springs and hot, dry summers provide ideal conditions for the foliage show we are experiencing in the corridor. But the changing of the leaves is not just wonderful to look at; it signifies a stage in the tree's life, and is a protective measure to allow it to survive winter.
Deciduous trees store all their nutrients in their roots and they absorb these nutrients in their leaves. Those amazing colour changes are triggered as the tree takes in essential nutrients.
During the long, wonderful, sunny summer, the leaves of trees are green because they are working at converting sun, water and carbon dioxide into sugars. The green pigment, chlorophyll, helps in this process too. The process of photosynthesis is an amazing trick and helps to support all life.
When summer dies down, daylight gets shorter, and the temperatures start to drop, changes in the leaves start to unfold. This is when the tree starts to work at taking in all those nutrients and storing them in the roots so they will be available next spring. As the tree takes in the last precious amounts of chlorophyll, the amazing colours we have come to expect in fall begin.
If you are looking for a beautiful and unusual deciduous tree that puts on a magnificent fall show, check out parrotia persica or the Persian ironwood tree. The tree has a wide spreading habit and is a member of the witch hazel (hamamelis) family. They are hardy, growing well in Zones 5 to 9 and thrive in our naturally acidic soil.
The leaves have a lovely crinkled nature and actually do look somewhat like parrot leaves. At full maturity it will get 20 to 30 feet tall and wide, so plant it in a spot where you have a bit of space to let its majesty unfold.
Persian ironwood's best claim to fame is the wonderful autumn foliage, which often starts off yellow, turning red and orange. It looks as if someone took a paintbrush to the leaves and it seems to change and delight for most of the fall.
An added bonus is the peeling bark, which adds winter interest, as well as the tiny pink flowers that grace the bare branches early in spring - a tree worth coveting.
