The hoptree (Ptelea trifoliata) is a deciduous shrub that’s native to North America, growing naturally in woodlands, prairies, ravines, rocky bluffs, and more. This adaptable shrub can get fairly large with a dense, rounded growth habit. And many people take advantage of that dense foliage by using it as a privacy hedge, even though the shrub drops its leaves for the winter.
Hoptree leaves are composed of three ovate leaflets that are a glossy dark green color before turning to greenish yellow or golden in the fall. The shrub’s bark is a red-brown to gray-brown color. In the late spring, clusters of small greenish-white flowers appear, attracting butterflies and other pollinators. But overall the plant is grown for its foliage. The shrub’s flowers, along with its foliage and bark when crushed, give off a musky, slightly lemony odor. Some people find it unpleasant while others don’t mind it. Hoptree has a slow growth rate and is best planted in the spring or fall.
|Botanical Name||Ptelea trifoliata|
|Common Names||Hoptree, common hoptree, stinking ash, skunk bush, wafer ash, swamp dogwood|
|Mature Size||15–20 ft. tall and wide|
|Sun Exposure||Partial, shade|
|Flower Color||Greenish white|
|Hardiness Zones||4–9 (USDA)|
|Native Area||North America|
Hoptree is a very versatile shrub that can adapt to many different growing conditions and doesn’t require much maintenance to keep it healthy. It typically needs only minimal pruning each year. And the shrub doesn’t have any serious issues with pests or diseases. It is notably deer resistant, yet its seeds provide food for birds and other wildlife.
When planting, be sure to select a site that has good soil drainage and can accommodate the mature size of the shrub. While mature shrubs are hardy, young shrubs should be protected from late frosts in the spring with a burlap sheet or other cover. In general, plan to water your hoptree during dry spells and feed it annually.
The shrub is commonly an understory plant in the wild, growing in sunlight that’s diffused by tall trees. Thus, it thrives in spots that get partial sunlight, meaning around three hours of direct sunlight on most days. It is also tolerant to even shadier conditions as well as to spots that get more sunlight if its moisture needs are met. However, harsh afternoon sun can scorch the shrub's foliage.
Hoptree grows well in a variety of soil types, including sandy, rocky, loamy, and even somewhat slow-draining clay soil. But it prefers a loamy soil that is rich in organic matter and has good drainage. Plus, it likes a relatively neutral soil pH.
Hoptree shrubs growing in shady conditions have moderate to low water needs. On the contrary, hoptree shrubs that get a lot of sun should have evenly moist (but not soggy) soil. The shrub does have some drought tolerance. So when grown in partial sunlight conditions, you’ll likely only have to water during prolonged dry spells or very hot temperatures. However, the soil on young hoptree shrubs should be kept consistently moist as they develop their root systems.
Temperature and Humidity
Hoptree shrubs can tolerate the wide range of temperatures within its growing zones quite well. However, frost and unseasonably cold temperatures can damage tender new growth in the spring. Humidity typically isn’t an issue. In very high humidity, good air flow around the shrub will help to prevent fungal diseases. And in very low humidity, make sure the shrub’s soil stays moist. A layer of mulch around the plant can help to retain soil moisture.
Hoptree shrubs prefer to grow in organically rich soil, but they also can thrive in average soil. Still, applying a balanced fertilizer in the spring can be helpful for growth. Also, mixing some compost into the soil, especially at the time of planting, can promote healthy growth.
There are numerous varieties of hoptree that vary slightly in appearance, including:
- Ptelea trifoliata ‘Aurea’: This variety features golden leaves that mature to a bright lime green color.
- Ptelea trifoliata ‘Glauca’: This shrub has blue-green leaves that turn to yellow in the fall.
- Ptelea trifoliata ‘Fastigiata’: This variety is known for its upright growth habit and is good for narrow spaces.
This shrub does not need extensive pruning to keep it looking tidy. If necessary, give your hoptree an annual prune over the winter while it’s dormant to clean up its shape. Remove any dead, damaged, or diseased portions as they arise. If you wish to promote more branching, cut back the stems by no more than a third of their full length just above a leaf node. And to prevent unwanted spread, remove suckers (stems growing up from the base of the plant).