Hoptree, Stinking Ash, Wafer Ash

Ptelea trifoliata

Family: Rutaceae (roo-TAY-see-ee) (Info)
Genus: Ptelea (TEL-ee-uh) (Info)
Species: trifoliata (try-foh-lee-AY-tuh) (Info)



Foliage Color:

Unknown - Tell us

Bloom Characteristics:

Unknown - Tell us

Water Requirements:

Average Water Needs; Water regularly; do not overwater

Where to Grow:

Unknown - Tell us


15-20 ft. (4.7-6 m)


12-15 ft. (3.6-4.7 m)


USDA Zone 5a: to -28.8 C (-20 F)

USDA Zone 5b: to -26.1 C (-15 F)

USDA Zone 6a: to -23.3 C (-10 F)

USDA Zone 6b: to -20.5 C (-5 F)

USDA Zone 7a: to -17.7 C (0 F)

USDA Zone 7b: to -14.9 C (5 F)

USDA Zone 8a: to -12.2 C (10 F)

USDA Zone 8b: to -9.4 C (15 F)

USDA Zone 9a: to -6.6 C (20 F)

USDA Zone 9b: to -3.8 C (25 F)

Sun Exposure:

Light Shade



Bloom Color:

Pale Green

Bloom Time:

Mid Summer




Other details:

Unknown - Tell us

Soil pH requirements:

5.1 to 5.5 (strongly acidic)

5.6 to 6.0 (acidic)

6.1 to 6.5 (mildly acidic)

6.6 to 7.5 (neutral)

7.6 to 7.8 (mildly alkaline)

Patent Information:


Propagation Methods:

From softwood cuttings

From semi-hardwood cuttings

From seed; direct sow outdoors in fall

Seed Collecting:

Allow pods to dry on plant; break open to collect seeds


This plant has been said to grow in the following regions:

Auburn, Alabama

Birmingham, Alabama

Little Rock, Arkansas

Morrilton, Arkansas

Cordele, Georgia

Mcdonough, Georgia

Moscow, Idaho

Lisle, Illinois

Benton, Kentucky

Clermont, Kentucky

Georgetown, Kentucky

Lexington, Kentucky

Louisville, Kentucky

Nicholasville, Kentucky

Crowley, Louisiana

Richmond, Massachusetts

Roslindale, Massachusetts

Wellfleet, Massachusetts

Kansas City, Missouri

Piedmont, Missouri

Erie, Pennsylvania

Austin, Texas (2 reports)

Dripping Springs, Texas

Fort Worth, Texas

Garland, Texas

Helotes, Texas

Marquez, Texas

New Braunfels, Texas

San Antonio, Texas (3 reports)

Cambridge, Wisconsin

Elmwood, Wisconsin

show all

Gardeners' Notes:


On Apr 29, 2016, klinc1234 from Little Rock, AR (Zone 7b) wrote:

I planted a baby hoptree in my yard one year ago, and it did fine through all of last year; but this year in the spring I discovered the plant was heavily infested with scale. Since part of the reason I bought this plant is to attract butterflies, I don't want to use neem oil or pesticides. This year I tried removing the scale by hand, and we'll see how things go from here. I have never seen any mention of scale on ptelea, but it makes sense it might be a problem for this member of the citrus family...


On Nov 11, 2014, flowergirl70 from Stayner, ON (Zone 5b) wrote:

A great little tree. Dark glossy green leaves, turning a med. yellow in fall, rather late, after most others. White fragrant flowers with rounded wafer like seeds afterwards. Bark is a reddish brown, also attractive.
Grows in my Zone 5a garden in Ontario, Canada, in full sun. No self seeding issues yet. And no butterflies yet.


On Aug 23, 2014, Rickwebb from Downingtown, PA wrote:

This is not a shrub-tree that is one of the flashy plants for the ornamental garden. This species goes well with the newer thinking from the American Native Plant Movement that one should plant for the sake of good ecology, being a food source for beneficial wildlife as birds and insects, and naturalizing, not just for ornament and decoration. It is an interesting plant, and one person in these files uses it to attract a butterfly species, which is very good. I used to have a photo of a wild specimen in northern Illinois that I found in the wild, but lost it long ago. It is not a common plant in most of its native range from TX to west NY and from central FL to central MI and also some of the Southwest.


On Mar 3, 2014, coriaceous from ROSLINDALE, MA wrote:

This performs in full sun and also in heavy shade. Native here and normally grows as a woodland understory tree, usually multitrunked.

In British gardening books this is often praised as one of the best of fragrant plants. The flower fragrance is strong enough to perfume the air, but I find it unpleasantly heavy. I find the green flowers are ornamentally insignificant.

This self-sows here to the point of weediness.

Dirr gives hardiness to Z3.


On Jul 7, 2013, gtbabic from The Villages, FL wrote:

In central FL, zone 9B, this might be a bit too far south for Hoptree (at least, the one I have). It was growing well through spring, then when real constant heat hit in July, it started to fade with wilted leaves. Now in mid-July it appears to be on its last legs with about half the leaves gone and the rest wilted. It is in full sun, perhaps if it was in part-shade the story would be different.


On Jul 29, 2011, Cuppagio from Erie, PA wrote:

Live in Northern Pennsylvania. This plant grows natively along the shores of Lake Erie. It will tolerate sun or shade and clay soil. We planted it to attract our summer butterflies like the Giant Swallowtail. Yes, Lake Erie has them, they fly up from south of here in the river valleys and then evidently because of the Rue family plants like Prickly Ash and Wafer Ash (Hoptree) they will breed and host here.

We put two of these shrubs/trees in our yards and one at a local school. From a distance they have a wonderful aroma when in bloom (here in Erie, June). The early leaves when crushed smell lemony. Later foliage has an unpleasant smell when crushed.

And finally, we now have Giant Swallowtails visiting our yard. Getting pictures of them is difficult as... read more


On Jun 30, 2011, xtrucker from Wellfleet, MA wrote:

We planted this little stick about 10 years ago and it is now a tree about 15 ft tall and 20 ft wide. It flowers every year but we have never seen the seed wafers. We wonder if it needs another Hoptree? It is beautiful in our zone 6 -7 but we have rough winters and it did loose some of it's limbs last year. We love it.


On Oct 5, 2008, LindaTX8 from NE Medina Co., TX (Zone 8a) wrote:

Hop Tree is a great small understory tree or a shrub that flowers with clusters of small greenish-white slightly fragrant flowers in spring and then makes the wafer-like seeds. It's a host plant for the caterpillars of the Giant Swallowtail and the Two-tailed Tiger Swallowtail, both large, beautiful butterflies. I wish I had lots of these little trees!


On Apr 28, 2006, rosemarysims from Mermentau, LA (Zone 8b) wrote:

I was surprised to see the comments of the scent of this tree. The reason I first noticed it was that in full bloom, the flowers cast their citrusy scent into the air. It drew me all the way across a large garden! It was like being in a orange grove at bloom time.

As for the scent of the foliage, I too find it to be mildly unpleasant, but the scent only manifests itself when a leaf is crushed.

Maybe there are strains of this far flung plant which differ in their scent characteristics?


On Jul 29, 2005, htop from San Antonio, TX (Zone 8b) wrote:

I have not grown thos plant so I am giving it a neutral rating.

Except in the extreme southern part, wafer ash is found throughout Texas. It can been found natively inhabiting a wide area in the United States including Arkansas, Florida, Louisiana, New York, Oklahoma and through the midwest, Arizona, California, Colorado and Utah. It grows in full sun to heavy shade, is adaptable to various soil types and ranges from dry rocky slopes to valley bottoms.

Classified as a shrub, it sometimes becomes a small tree growing to 18 feet. Its trifoliate leaflets vary in size and shape. The dark green, lustrous leaves may be alternate or opposite and in some varieties pubescent. The dioecious, small, yellowish blooms are somewhat fragrant; although, most of the other pa... read more


On Jan 2, 2005, peter_z from St. Petersburg,
Russia wrote:

Ptelea is hardy enough outdoors in St. Petersburg, Russia (=usda zone 4a). Here it looks like a shrub (2-4m height).


On Sep 1, 2001, mystic from Ewing, KY (Zone 6a) wrote:

This is a small,deciduous tree or a large shrub depending upon where the plant grows.The bark and leaves are bitter, strongly scented. It has a straight, slender trunk, 68 inches in diameter,and seldom reaches a height of more than 20 feet.Has shiny,dark green leaves which turn greenish yellow in fall.The flowers are greenish-white and unpleasantly scented.This tree flowers in June.The fruit matures in September or October.The fruit is small,round, two-seeded,winged and pale green that stay on the tree over the winter.