Skip to main content
WildScope
Search

Invasive plant

Callery pear

Pyrus calleryana

Callery pear identification: white five-petaled flowers before the leaves, glossy wavy leaves and a rancid spring smell.

By WildScope Editorial Desk

Published Last reviewed

Callery pear (Pyrus calleryana)
Photo: MOHAMMED HAMZA · CC BY-SA · source
Callery pear (Pyrus calleryana), photo 2
Photo: MOHAMMED HAMZA · CC BY-SA · source
Callery pear (Pyrus calleryana), photo 3
Photo: MOHAMMED HAMZA · CC BY-SA · source

If the white tree in your yard smells like rotting fish in early spring, it is probably Callery pear. The smell is not the main problem. Birds eat its fruit and spread the seed into fields and roadsides, different cultivars cross-pollinate to make fertile seed, and the tree’s tight branch forks make it a storm risk. The first decision is whether to remove it and what your state allows.

Why it smells, and when it blooms

Callery pear flowers open before the leaves expand. Penn State Extension describes several white, five-petaled flowers held in a ball-shaped bundle, each about 3/4 inch across, with a strong rancid odor. The Ohio Department of Natural Resources compares the smell to rotting fish. It is noticeable while the tree is in full bloom, which is also the easiest time to spot the tree along a highway or field edge.

The smell is a useful identification clue, not a health hazard in the sources reviewed here. The more important spring clue is the timing: flowers first, leaves later.

The “sterile” Bradford pear problem

Callery pear was imported to the United States in the early 1900s as rootstock for domesticated pears. The Bradford cultivar was bred to be sterile and was planted widely as a street and ornamental tree. It did not stay sterile in the landscape.

Penn State Extension explains why: when different cultivars grow close enough for insect pollination, they often produce fertile seed. Wild seedlings then interbreed and produce more viable seed. Birds eat the small pears and spread the seed in their droppings. The tree also spreads vegetatively by sending up new shoots from its shallow root system. That combination is why a tree in a yard can seed a field across the road.

There is a second cost. The National Invasive Species Information Center notes that the Bradford cultivar has narrow branch angles and is extremely susceptible to storm damage. Trees can split under their own weight after 15 to 20 years.

State rules at a glance

Restrictions are changing, and they apply to the seller and the buyer differently. Where a ban is in place, nurseries and garden centers may not sell the tree. This table records what the cited agency said when checked on 2026-11-03.

State Status What it means in practice
Ohio Prohibited It is illegal to sell, grow or plant Callery pear. Existing trees do not have to be removed, but the Ohio Department of Natural Resources encourages control and removal.
South Carolina Prohibited for nursery sale The state banned nursery sales of Bradford pear and other pears grown on Callery pear rootstock, starting October 1, 2024, according to the National Invasive Species Information Center.
Pennsylvania Noxious (Class B) It cannot be sold, transported, planted or propagated in the state. Class B means it is widely established and cannot feasibly be eradicated.
Kansas Ban reported NC State Extension reports that Kansas enacted a ban between 2021 and 2024. Confirm the scope and date with the Kansas Department of Agriculture.

This table is not a substitute for your state’s current rule. If you live somewhere else, check your state agriculture department before you buy, plant or move a tree. For state-level lists and reporting contacts, see the Pennsylvania and Virginia pages.

How to tell it from a native flowering tree

The leaf arrangement is the first check. Callery pear leaves are alternate. Flowering dogwood and viburnums have opposite leaves. Alternate-leaf dogwood also has alternate leaves, but its branches emerge in whorls rather than in the tight, upright forks of Callery pear.

Then check the leaf itself: thick, waxy, rounded or teardrop-shaped, 1.5 to 3 inches long, with a finely toothed, wavy edge. In spring, look for the white five-petaled flowers in ball-shaped clusters and the rancid smell. In fall, look for tiny hard pears about 1/2 inch across, green to brown with pale dots.

Serviceberry and black cherry also have alternate leaves, so leaf arrangement alone will not separate them. NC State Extension lists both among the white-flowering spring trees that can be confused with Callery pear. Use the fruit as the final check: if it is not a tiny hard pear, do not assume the tree is Callery pear.

Naturalized trees can have stout spines, so do not assume a thorny tree is something else.

What to do this spring

  1. Do not plant another Callery pear, even a “sterile” cultivar.
  2. Check your state rule before you buy, sell or move a tree.
  3. If you remove a tree, plan for the stump. Cutting alone will resprout; use a cut-stump, basal-bark or hack-and-squirt treatment described by Penn State Extension.
  4. Remove or bag fruit if you are cutting a tree that has fruit, so seed is not spread around the site.
  5. Watch the area for seedlings for several years. A nearby seed source can reinfest the site.

For the step-by-step removal method, including cut-stump, basal-bark and hack-and-squirt options, see how to remove Bradford pear and Callery pear. For prevention and replacement planting, see prevention. More profiles are listed under invasive plants, and image credits are on the image credits page.

Identification

Look for the combination of characters below. A single feature is rarely enough, especially when a native look-alike is present.

Size and form
A small tree, rarely more than 40 feet tall with a trunk less than 1 foot in diameter. The branches form tight, upright forks, which makes the tree prone to splitting in storms.
Leaves
Alternate, rounded or teardrop-shaped, thick and waxy, about 1.5 to 3 inches long and wide. The edge is finely toothed and has a distinct ripple or wave.
Flowers
White, five-petaled flowers about 3/4 inch across, held in ball-shaped clusters. They open before the leaves expand and produce a strong, rancid odor.
Fruit
Tiny, hard pears about 1/2 inch in diameter, green to brown with pale dots, held in the same clusters as the flowers. They stay almost woody until frost softens them.
Bark and spines
Grayish-brown bark, smooth on young limbs and deeply fissured or scaly on older trees. Naturalized trees often have stout spines, even though the original cultivar was bred to be spineless.

Look-alikes

  • Flowering dogwood

    Cornus florida

    Flowering dogwood has rounded, leathery leaves like Callery pear, but its leaves are opposite rather than alternate. Its flowers sit in a different structure and it does not produce small hard pears.

  • Viburnum

    Viburnum species

    Viburnums also have rounded, leathery leaves, but they are arranged in opposite pairs. Callery pear leaves are alternate.

  • Alternate-leaf dogwood

    Cornus alternifolia

    Alternate-leaf dogwood has alternate leaves, but its branches emerge in whorls rather than in the tight, upright forks of Callery pear.

Range and status

Native range: East Asia

Regulatory status by state

  • pennsylvania Noxious weed

    Callery pear is a Class B noxious weed on the Pennsylvania Department of Agriculture list. Noxious weeds cannot be sold, transported, planted or otherwise propagated in the state. Class B means the plant is widely established and cannot feasibly be eradicated.

    Regulatory source

  • new-york Not on the state noxious-weed list

    Callery pear is not on the 6 NYCRR Part 575 prohibited or regulated plant list.

    Regulatory source

  • Virginia Not on the state noxious-weed list

    Callery pear is not on Virginia's VDACS noxious weed list in 2VAC5-317-20. The separate DCR invasive plant list is advisory only.

    Virginia state profile Regulatory source

  • ohio Prohibited

    Callery pear is on Ohio's invasive plant list under OAC 901:5-30-01, which bans selling, propagating, distributing, importing or intentionally spreading it.

    Regulatory source

  • wisconsin Not on the state noxious-weed list

    Callery pear is not on Wisconsin's NR 40 prohibited or restricted species list.

    Regulatory source

Why it matters

Callery pear escapes yards and spreads into old fields, roadsides and forest edges, where it forms dense thorny thickets. Its flowers smell bad, its fruit litters pavement, and its tight branch forks make it prone to storm damage. Birds carry the seed far from the parent tree, so removing one tree does not solve the problem if other Callery pears are nearby.

Management

Start with the smallest plants

Pull small seedlings by hand, but remove all roots because root fragments often resprout. Cutting or mowing alone is not enough; Penn State Extension says plants readily resprout and the cut area must be followed with an herbicide treatment.

Treat the stump or the bark

Penn State Extension describes cut-stump, basal-bark and hack-and-squirt treatments. Basal bark works on stems under 6 inches in diameter and can be applied year-round when snow or water does not prevent spraying to the ground line. For larger stems, switch to hack-and-squirt.

Treat dense stands of small trees

For low to moderate density stands with trees less than 10 feet tall, Penn State Extension describes a foliar treatment using glyphosate plus a water-based triclopyr formulation. Many other products used in agriculture are not labeled for forest or natural-area use. Follow the product label; the label is the law.

Follow the label and expect reinvasion

Follow the product label; the label is the law. Callery pear is persistent and will likely reinvade as long as a seed source remains nearby, so plan on repeated surveillance rather than a one-time removal.

Sources

Facts on this page were checked against the sources below. Each link shows the date the source was accessed.

  1. Callery Pear — Penn State Extension Accessed November 3, 2026
  2. Callery Pear — USDA National Invasive Species Information Center Accessed November 3, 2026
  3. Planting Callery Pear No Longer Permitted in Ohio — Ohio Department of Natural Resources Accessed November 3, 2026
  4. Pyrus calleryana Decne. (Callery pear) — USDA NRCS PLANTS Database Accessed November 3, 2026
  5. Controlled Plant & Noxious Weed Lists — Pennsylvania Department of Agriculture Accessed November 3, 2026
  6. Callery Pear: Bradford Pear, Other Varieties, and Their Invasive Offspring — NC State Extension Accessed November 3, 2026

Related pages