Master Gardener Q&A: Warm fall means second round for Mexican orange

Question: This week I saw this rounded green shrub down the street from me, and it was covered with these small white flowers. They had a nice fragrance. What is this plant?

Answer: The plant you saw is called Mexican orange (Choisya ternata). It is a broadleaf evergreen shrub native to Mexico. There are several cultivars of this plant, including one with yellow foliage called ‘Sundance,’ as well as ‘Aztec Pearl,’ which is a hybid between Choisya ternata and C. arizonica.

Despite their origin, these shrubs are very hardy in Western Oregon, although they may suffer injury in very cold winters.

MORE: Find more gardening Q&A from Neil Bell.

What you are observing is one of the interesting characteristics of this plant, in that it is re-blooming. Mexican Orange is really a spring-blooming shrub, with a long flowering period in April and May. But it commonly will bloom again in the fall if conditions are right. The cool, wet weather in October, followed by the unusually warm temperatures at the beginning of November, appear to have provided perfect conditions for this to occur. It’s likely that the excess bloom now will reduce the amount of flowers next spring.

The Master Gardeners’ Question of the Week is courtesy of Oregon State University Extension Service’s Master Gardeners. The Master Gardeners are trained volunteers who offer homeowners help with gardening problems. Call 503-373-3770 in Marion County or 503-623-8395 in Polk County to talk with a Master Gardener.