Q&A: Potted Orange Tree Sheds Fruit

Q: I have a potted orange tree that blooms profusely and sets fruit readily, but the fruit falls off when still quite small. Why? The plant summers outside and is in a sunroom during fall and winter.
— L.M., Guelph, ON

A: Citrus-fruit drop when the fruits are still small is a natural thinning process. The tree can't supply nutrients and support all the fruit that it can set, so it drops some of it. Citrus trees in an orchard will do the same thing. Be sure to keep your tree regularly watered and fertilized with a nitrogen source. Citrus is a heavy feeder.

— National Gardening Association