Native to North American woodlands mostly in the eastern United States, the hop tree is an easy-to-grow large shrub or small tree maturing at around 20 feet in height. Also called wafer ash or water ash, hop tree gets its more common name from the bitter, aromatic fruit, which was said to be tested as a substitute for hops in the making of beer. Hop tree has large leaves consisting of several individual leaflets that resemble those of the ash tree. They’re shiny, dark green on top, pale and hairy beneath, and they turn greenish yellow in autumn. Hop tree’s fragrant, greenish-white flowers are rather inconspicuous, appearing in early summer, and they attract pollinators. The flowers are usually followed by showy seeds that have more prominence because they are surrounded by papery wings that give them a wafer-like appearance. Seeds mature from bright green to brown, staying on the tree through fall and winter, when they serve as food for wildlife.
Hop Tree Overview
Where to Plant Hop Tree
Hop tree adapts to different light conditions but it does best in full to partial shade. Because it is a modest size, it is a natural choice for anyone looking for a dependable understory tree to plant beneath a high-branched shade tree. The soil should be well-drained and in the neutral pH range.
Hop tree can also be planted as part of natural hedgerow or shelterbelt. Its lustrous leaves, showy seeds, and chestnut brown bark on young stems are attractive enough to warrant a place in a larger shrub bed. It pairs well with showy companions, particularly those with darker foliage, such as purpleleaf sandcherry and chokecherry. In shady locations, you can plant it instead of azalea, rhododendron, ferns, and myrtle.
How and When to Plant Hop Tree
It is best planted or transplanted when dormant, either in early spring or late fall. Dig a hole that is at least twice as wide and 6 inches deeper than the tree’s root ball. Position the tree in the planting hole so the top of the rootball is level with the soil. Backfill with the original soil and tamp it down. Water the newly planted tree regularly during the first year after planting—about 1 inch per week in the absence of rain.
Hop Tree Care Tips
Light
Although hop tree tolerates full sun, it does best in partial to full shade, which mimics the light conditions in its natural habitat as an understory tree.
Soil and Water
Hop tree is adaptable, growing easily in a variety of soil types, including slow-draining clay and fast-draining sandy loam, but it does best in moist soil with plenty of organic matter and a pH in the neutral range (6.8 to 7.2).
Temperature and Humidity
Hop tree is the hardiest member of the citrus family (Rutaceae) and suitable both for cold and warm climates. It is scattered over a large geographic range, growing as far north as zone 3.
High humidity is usually not a problem as long as there is good air flow around the tree, as trapped moisture can foster the spread of fungal diseases.
Fertilizer
If you’ve planted the tree in fertile soil with plenty of organic matter, there is no need to fertilize the tree other than adding a layer of compost or leaf mold around the base every year.
Pruning
Dead or broken branches can be removed any time. Pruning to improve the shape of the tree should be done when the plant is dormant. The spreading, multi-stem shape of the tree responds well to hard pruning if you prefer a tidier, more formal look. The tree does tend to sucker, so you may need to remove newly formed stems arising from the ground.
Pests and Problems
Hop tree has no serious pest or disease issues. Occasionally it will get tree hoppers whose feeding leads to discolored foliage and defoliation. Other potential diseases are leaf spot and rust.
How to Propagate Hop Tree
Hop tree can be propagated from seed and cuttings, which is faster and therefore the preferred method. In midsummer to fall, take softwood or semi-hardwood cuttings, about 6 inches long. Remove all the lower leaves and dip the cut ends in rooting hormone powder.
Fill a 1-quart pot with well-draining, damp potting soil. Insert the cutting into the pot about halfway and keep it well-watered at all times in a location with bright light but away from direct sunlight. After the cutting has rooted (you can tell by gently tugging on it), let it grow into a strong sapling for another year before transplanting it in the landscape. Leave the container outside during the winter but bury it in a corner of your yard in garden soil to protect the roots from cold damage.
Types of Hop Tree
'Aurea’
Ptelea trifoliata 'Aurea', also called golden hoptree, is a cultivar with bright yellow leaves that mature to lime green in the late summer. It grows 15 feet in height and spreads 10 to 15 feet.
‘Glauca’
Ptelea trifoliata 'Glauca' is a cultivar with blue-green leaves, with a mature size the same as ‘Aurea’.
Hop Tree Companion Plants
Ninebark
With its striking foliage and appealing winter bark, fast-growing ninebark shrub is a landscape favorite. As the bark of the older stems ages, it peels back in layers, creating an exfoliation effect. Another plus: Ninebark is deer-resistant. Zone 3-7
Smokebush
The velvet-purple foliage that changes to a rich shade of orange-red in the fall is not the only attractive feature of smokebush (Cotinus coggygria). In early summer, it bears fluffy clusters of pink flowers in early summer. Smokebush thrives in a wide range of soil types and it is also deer-resistant. Zone 5-8
'Forest Pansy' Redbud
Cercis canadensis 'Forest Pansy' is a redbud cultivar with pink flowers and rich purple foliage in the spring that fades to deep green in summer. It is less hardy than a hop tree but still a good companion plant for the upper end of its climate zone range. Zone 6-9
Frequently Asked Questions
- How fast do hop trees grow?They are slow to medium growers, adding about 1 to 2 feet every year.
They are slow to medium growers, adding about 1 to 2 feet every year.
- What is the wildlife value of hop trees?Hop tree is a food source for the caterpillars of the giant swallowtail butterfly. It also provides food for birds and mammals and nectar for butterflies and bees.
Hop tree is a food source for the caterpillars of the giant swallowtail butterfly. It also provides food for birds and mammals and nectar for butterflies and bees.