The Chinese chestnut tree in full bloom can be very attractive. Photo: Tom Butzler, Penn State
As an example, there is nothing better than sitting on the back porch when a soft spring breeze brushes over lilac flowers. That sweet fragrance can forever be embedded into our memory. But that can work both ways as unpleasant smells also stick around in our consciousness. There are several trees and shrubs utilized in the landscape that emit some pretty stinky odors.
Boxwoods are great in the landscape as they have foliage year round, withstand sunny to partially sunny areas of the landscape, and can be heavily pruned into animal shapes (if you are into that kind of thing). Be aware that there are some boxwoods, such as Buxus sempervirens ‘Suffruiticosa’, that can add an interesting smell to the landscape when the leaves are disturbed. A Virginia Tech publication describes it like this, ‘This cultivar has the strong ‘aroma’ that has been likened to cat urine. Some people wane nostalgic while others flee the plants when smelling this cultivar.’
A popular spring flowering tree for the landscape is the ornamental pear (Pyrus calleryana). The whole tree is covered by white blossoms before the foliage appears. It is beautiful to look at but not so nice on the senses, especially if several are nearby. Upon reviewing several fact sheets, it appears that consensus is that the flowers emit an odor that is reminiscent of rotten fish.
The blooms of ornamental pears are very showy but not the best smelling. Photo: Tom Butzler, Penn State
Chinese chestnuts (Castanea mollissima) are often added to the edible landscape as the tree can produce copious amount of nuts in the fall (both for humans or wildlife). But to get those nuts, flowers have to come first. A North Carolina State Extension fact sheet politely states that the ‘smell of the flower might be offensive to some people’ while University of Connecticut‘s Plant Database states that the flower emits a ‘foul odor.’ It is up to you and your favorite internet search engine to see what people really think of this smell.
The flowers of Chinese chestnut can emit an unpleasant odor throughout the neighborhood. Photo: Tom Butzler, Penn State
How about the stately ginkgo (Ginkgo biloba)? These are dioecious, where male flowers are on one tree and the female on a different tree. So only the trees with the female flowers have fruit (not a true fruit but that is another article for another day). In the fall, the fruit matures and falls to the ground where it starts to decompose. Various writers and bloggers describe the smell as reminding them of vomit, rancid butter, dog-poo, and puke.
Ginkgo ‘fruit’ is not a true fruit but a naked seed. Photo: Michael Masiuk, Penn State
Many landscapes are designed to have something of interest all season long so we have something pretty to look out. A smelly design can be achieved in the same way. While the ornamental pear and Chinese chestnut take care of the spring and summer respectively, the rotting flesh of the ginkgo fruit completes the offensive smells toward the end of the growing season. You can throw in the boxwood as a plant that just keeps on giving all season long.