Tree Litter Kevin Dunn 1) Leaves What makes a particular species of tree messy while another one is considered clean? I count 5 factors: 1)Leaves a) Ideal Trees (Ginkgo and Oriental Spruce) Ginkgo Tree/Clean Tree Oriental Spruce/Clean Tree Leaves b) Winter Leaf Retention (Pin Oak and Shingle Oak) c) Leaves that decompose slowly (Evergreen Magnolias, Oaks, and Sycamores) vs Quick decomposers (Maples, Elms, and Tulip trees) Brackens Evergreen Magnolia Sycamore Sugar Maple Tulip Tree Princeton American Elm Leaves d) Leaf drop due to disease or environmental stress, disease resistant Crabapples, River Birch vs Prairie Gold Aspen Crabapple Tree River Birch Prairie Gold Aspen 2)Weak, brittle wood Many times, it’s the faster growing trees that produce the weakest wood. Silver maples, willows, Siberian elms, and Callery pears such as the Bradford are examples. These trees are all susceptible to breaking up from ice storms, thunderstorms, or high winds. Weak, brittle wood Consider planting slower growers with stronger wood such as Sugar maples, disease resistant cultivars of American elm such as Princeton, or parrotia also called Persian ironwood. Some of the slower growing native oaks have some of the strongest wood, e.g., burr oak which has stronger wood than the much faster growing pin oak. Parrotia Tree Burr Oak 3) Fruit Examples include acorns, pine cones, drupes (dogwood trees and hollies), aggregate of follicles (magnolia), samara (maple trees), a syncarp of drupes (hedge apple tree), berry-like pome (serviceberry), pome (crabapple), pod (locust trees, redbuds), gumballs (sweetgum tree) Nellie Stevens Holly Honey Locust Tree Fruit Birds and other animals often eat the fruit of some trees before it ever drops. Up to 43 species of birds eat the fruit and buds on the native dogwood, Cornus florida. Serviceberry is another tree which the birds usually pick clean before fruit can fall. Dogwood Tree Fruit Some crabapples tend to hold onto their fruit longer such as Red Jewel, Donald Wyman, and Indian Magic. The fruit stays on through the winter and becomes an important source of food for birds in late winter months. Adironack Crabapple Fruit Black cherry (Prunus serotina) – valuable for wildlife but can be weedy Big litter problem with other fruit: evergreen magnolia (“hand grenade” tree), hedge apples, persimmons, pine cones. Brackens Magnolia Fruit One solution is to use male or sterile cultivars: Brandywine red maple, ginkgo, Espresso Kentucky Coffee Tree, Wichita cultivar of osage orange, problems with fruitless Spring Snow crabapple. Espresso Kentucky Coffee 4)Flowers Big flowers and/or smelly flowers – Chinese chestnut, Callery pears, catalpa, some magnolias, Japanese tree lilac flowers turn brown with age Clean option: sweetbay magnolia is a great flowering tree for patio area Sweetbay Magnolia 5)Weediness If you plant one, you’ll get a thousand seedlings Worst offenders: Mulberry trees, ailanthus, Siberian elm, Callery pears – now considered invasive Siberian Elm Why are some trees worth all the bother of their litter? 1)Environmental Value to wildlife– value to bees, other pollinators, butterflies, birds, etc. Many native trees are host plants for specific moths and butterflies. E.g., pawpaw trees are the sole host source for zebra swallowtail. Hackberry trees are hosts or six different species of butterflies. Sweetgum and persimmon as host plants for Luna moths. Why are some trees worth all the bother of their litter? 2)Value for People Heartland Tree Alliance information: A single tree can produce enough oxygen to sustain four people and it will take 48 pounds of carbon dioxide out of the air every year. In Kansas City, an estimated 605,702,000 gallons of rainfall are intercepted by street trees saving the city more than $16 million in management costs. The net cooling effect of a young healthy tree is equivalent to 10 room-size air conditioners running 20 hours per day. Trees properly placed around buildings can reduce air conditioning needs by 30 percent and can save 20 percent to 50 percent in energy used for heating. Why are some trees worth all the bother of their litter? 3)Aesthetic and/or Historic value As some trees grow larger with age, they may produce more litter, but they also become more majestic, e.g., burr oak with the largest of any acorn. Their sheer size inspires us. Symmetrical white pines become more distinctive with age. Michael Dirr, author of Manual of Woody Landscape Plants, calls it one of our most beautiful native pines. White Pine Why are some trees worth all the bother of their litter? The messy evergreen magnolia is also called the aristocrat of broadleaf evergreens. Mature burr oaks are often called “mighty” or “majestic”. Maybe an even better word is inspirational. They inspire us with their age – some live to be more than 300 years old. They inspire us with their endurance – burr oaks are one of the fire resistant of all tree species. Somehow they can even survive prairie wildfires. And like many trees, they inspire with their beauty. We may not have a nearby ocean or mountain range in Kansas City but we have our beautiful trees that give so much back in return for the care we give them. .