The Dallas County Roadside Management Program, in partnership with Bentley Ridge Tree Farm and Nursery and the Iowa Weed Commissioners’ Association, is holding a callery pear “buy-back” program for Dallas County residents. Cut down your existing callery pear tree and receive a certificate for a free native tree, redeemable at Bentley Ridge Tree Farm in Grimes.
The invasive spread of callery pear trees has been well-documented across the eastern half of the United States over the last few decades. They are now beginning to spread in central and eastern Iowa and pose a significant ecological threat to our state.
Commonly referred to as flowering pear, ornamental pear, or Bradford pear, callery pear trees (Pyrus calleryana) are native to China and include over two dozen cultivars, of which Bradford is one. Some of the more common cultivars sold commercially include Aristocrat, Autumn Blaze, Capital, Cleveland Select, Chanticleer, Red-spire and Whitehouse.
Callery pear usually exhibits a pyramidal or egg-shaped form. Limbs tend to grow vertically, forming very narrow or tight crotch angles that are prone to breaking in windstorms. When mature, trees reach heights of 25-40 feet.
In Iowa, callery pear typically blooms around mid-late April, with very dense clusters of white flowers that cover the tree before leaf out. Their white petals touch or overlap, and their blossoms have an unpleasant odor, commonly described as that of fish or dirty diapers. To prevent the trees from spreading, property owners should remove trees during flowering, when callery pear is easy to identify.
Individual cultivars typically do not produce fertile seeds on their own. However, insect pollination of flowers from different cultivars nearby can produce viable seed. Seeds are found in small fruits which are consumed by birds that disperse fertile seeds across the landscape. ‘Escaped’ trees grow very rapidly, and often revert to the wild form of the tree with long thorns. These ‘escapees’ produce lots of seed which birds further spread across the landscape
Each year, as trees get older and different cultivars are planted close together in urban landscapes, the amount of viable seed increases. Removing existing trees, choosing native/non-invasive alternatives for future plantings and controlling existing invasive populations prevents the invasive spread of this species.
The spread of callery pear threatens our natural areas as it displaces native plants which in turn hurts our wildlife that depend on native vegetation. It also poses a threat to pastures as it shades out forage plants and forms thickets with large thorns that deter livestock from grazing it.
Participants in the buy-back program will be able to obtain a free potted replacement tree at Bentley Ridge Tree Farm and Nursery in Grimes. Trees are being donated by Bentley Ridge and the Iowa Weed Commissioners’ Association and come in 5-10-gallon containers while standing 6+ feet tall. To be eligible for a replacement tree, participants must submit their name and address and two photos of themselves, one next to their callery pear tree in flower and one next to their cut-down callery pear tree in flower. Replacement trees are limited to the first 15 participants. Limit one replacement tree per participant.
To receive a certificate for your replacement tree, email your before and after pictures, along with your name and address to Dallas County Roadside Biologist Jim Uthe at [email protected]
Subject to availability, choices of native replacement trees include: Oaks – Bur, Red, Swamp White, Northern Pin; Elm – Americana (Princeton, Prairie Expedition Elm); Redbud; Canada Red Chokecherry; Coffeetree – Espresso Kentucky Coffeetree; Prairie Gold Aspen; Hackberry; Autumn Brilliance Serviceberry; Ironwood; Fall Fiesta Sugar Maple.