Stinky Ginkgo Fruit

Mike Mickelbart, Assistant Professor, Department of Horticulture & Landscape Architecture, Purdue Univ.

This time of year, some of the ginkgo trees that were so stately in summer and so colorful in fall are creating a big stinky mess with their fruit. Gingko trees are dioecious, which means male and female plants on are separate plants (the word translated means “two houses”). The female plants produce the round yellowish-orange gingko fruit. The fruit give off a rancid smell that most people find very unpleasant. This tree is located on the Purdue campus in a spot with a lot of foot traffic. These days, gingko cultivars such as Princeton Sentry® and Autumn Blaze™ that are fruitless (all males) can be purchased from retail nurseries, so the fruit is not a problem. What if you have an older gingko tree that was planted before these cultivars were available? One option is to use a hormone spray to cause the fruit to drop at an early stage of development. The use of these sprays to thin fruit trees (to allow for fewer but larger fruit) is common. In ornamentals, success in causing fruit drop is usually not that your customers need to realize that the results are 100% effective. Furthermore, this is an effective strategy for smaller trees, but coverage may be a problem with large trees (usually the trees you want to keep from fruiting!). Most of these sprays are napthyleneacetic acid (NAA) or NAA derivatives and they go by a number of commercial names. Ask your local retail garden center staff if they carry these products. Also, be sure to consult with them on application rates and timing, since these are the most important factors for success. Of course, if you are planting a new ginkgo tree, be sure you purchase a named male cultivar to avoid this messy problem in the future

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Gingko tree with fruit on ground