Daphne

Annie writes~ My Daphne is in a large tub (approx. 15" across). I've noticed some of the leaves are turning yellow. Why would this be? (Here in New Zealand, we are presently in Autumn.)

A. Thanks for telling me where you are. I do feel that the fall has much to do with it coupled with the age of the plant. As the light decreases and the temperatures fall, Daphne drop their oldest leaves. These are the ones which are tired, and you have quite a large plant! They are no longer pulling their share. The purpose of leaves is to produce food. Once they get old and tired, the mother plant no longer wants them to partake in the limited share of water and food. Therefore, it is only natural that the oldest, weakest leaves go first. Survival of the fittest and the ones which are pulling their share.

The yellowing signifies that they are losing chlorophyll, and if you remember from class, that is needed for photosynthesis to produce food. Once their need is gone, they are dropped. A plant is very smart, and has evolved through the centuries with one thought in mind, survival. Abscission is what this leaf dropping is called.