Jane e-mailed: I have a question about my lemon tree. I bought a new one and planted it in a few weeks ago, and this week we have had a lot of rain. It has a fair bit of new growth, but the new leaves are red in some places. Is there something wrong with my tree?
You have no reason to worry Jane, as you certainly have a healthy-looking tree.
Red colouring in new leaves is a common occurrence in plants that have adult leaves with a leathery texture, including avocado, citrus, eucalypts, oaks and roses. The colour is caused by the tree producing red anthocyanins (a type of antioxidant). These are believed to protect the young, tender leaves from ultra-violet light. The leaves will turn green as they toughen.
When citrus produce a lot of new growth as the weather cools, an application to the soil around the tree of seaweed extract at weak black tea strength will build the tree’s resistance to the effects of cold weather. Seaweed contains compounds that strengthen cell walls.