TREE TIPS TREE & SHRUB CARE FROM BARTLETT TREE EXPERTS

Organic disease management by Drew Zwart, PhD Emerald ash borer in southeastern Whether in the grocery store or the The true “safest” or most landscape, the last decade has seen a environmentally responsible method United States dramatic rise in interest in “organic” for managing landscape disease The Emerald Ash Borer (EAB) began products and services. A common employs an integrated combination its attack on ash trees in the United assumption with organically registered of cultural practices and preventive States near Detroit, Michigan, in products and materials is that they are treatments. Addressing adverse 2002. Since then the beetle has healthier, safer, or are produced in a growing conditions, practicing more sustainable or environmentally sanitation when pathogens are friendly manner. present, and choosing appropriate plant species for a given region are Our goal is a sustainable, all “organic” practices that can limit ecologically beneficial landscape. landscape disease. In addition, using “bio-rational”, or naturally derived This, however, is often not the case. It materials—those that are produced in is important to consider that “certified nature but altered slightly for landscape organic” does not always mean “safer” use—is another environmentally sound and certainly does not mean “chemical practice to manage disease while free”. Often, organically produced fruit minimizing the number of applications or vegetables actually needed more and the potential effects on non- applications in a growing season than target organisms. Purely organic if grown using standard practices. disease management programs are The same is true in the landscape: available, but for a true sustainable There are whereas most common foliar diseases and ecologically beneficial landscape, protective can be managed using certified organic an integrated approach using a treatments, but materials, in some cases doing so combination of biological, cultural, the threat from will result in lesser control of target and chemical (organic or otherwise) EAB remains! organisms, increased number of options is often the best practice. required treatments, or increased effect on non-target organisms.

steadily spread and killed hundreds of millions of ash trees throughout much of their native range. EAB is now found in 31 states and two Canadian provinces and has cost property owners and municipalities untold millions of dollars. In these areas, ash often occupy lowlands and provide benefits such as preventing erosion and protecting water quality. Ash then frequently become components of the Continued on page 2 Emerald ash borer (Continued from page 1)

TREE & SHRUB residential landscape once these natural be performed. MAINTENANCE CALENDAR areas become developed. Ash trees can be protected from MARCH In North Carolina, South Carolina, this invasive pest; Tennessee, Georgia and Alabama, as Begin to uncover and remove protective wraps research and experience has shown as temperatures warm in other areas of the country, frequent great results from product treatments. Prune out dead canes from roses inspections of ash for signs and symptoms of EAB infestations must Have a soil sample done to assess soil fertility Plant new trees and shrubs as soon as soil is dry enough to be worked Assess desiccation injury as plants come out of Arborists volunteer dormancy at local park Have plants checked for overwintering scale insects, mites and aphids – treat as needed Waterford Park in Frederick, Maryland, got a good start this spring, thanks to Monitor for newly hatched fall cankerworm and winter moth larvae eating plant buds community efforts last year. On a cool day in early December, our local office Begin foliage disease management contributed a day of volunteer service Begin treatments to suppress boring insects alongside Friends of Waterford APRIL Park Board president Ginny Brace and park neighbors. Bartlett’s Matt Begin spring deer management applications Delimont, Chris Bartholomew, Prune out dead and damaged tree branches Heather Simpson, and Dan Yates Address soil fertility needs removed dead trees and branches Pest monitoring from March should continue over the shared-use paths, pruned Inspect for lace bug on azaleas – treat as young trees to improve their needed branch structure, and improved the Inspect for gypsy moth – treat as they hatch and spacing of trees and low limbs in begin to feed the food forest. Waterford Park is Continue foliage disease management and unique in the city park system for boring insect suppression treatments its emphasis on native plants and Pre-bloom orchard sprays to fruit trees diverse naturalized ecosystems. Remove guy wires and rope from fall-planted trees to prevent girdling MAY Prune early spring blooming shrubs and trees Fun with trees after flowers fade Put up a birdhouse this spring Start tick treatment of yard perimeters and trail edges Many bird species will use a birdhouse. Bluebirds, purple martins, house wrens, chickadees, tree Crape myrtles should be checked for aphids and treated as needed swallows and house sparrows are some common ones. Visit nestwatch.org to find out which birds nest in Have fruit on apple trees thinned to 8” apart if needed your region and habitat (https://nestwatch.org/learn/ all-about-birdhouses/right-bird-right-house/). Continue foliage disease management and boring insect suppression treatments To attract specific birds, select a house that meets their particular needs. Requirements include selecting a Timely Tip: Be careful to avoid nicking the trunks of trees proper house design with the right size entrance hole with lawnmowers and weed trimmers and hanging the house at the right height to attract the birds you want. It is also important to pick an appropriate location that is hard for predators to reach. TREE FOCUS: Paperbark maple (Acer griseum)

History Acer griseum was brought from China to Europe in 1901 by E.H. Wilson, and to the United States soon after. It is not a common garden plant, in part because Wilson started with only approximately 100 seedlings, which provided little genetic diversity in this country. In addition, this tree produces very few fertile seeds, and cuttings don’t root. Although paperbark maple is found naturally over a large area of central China, it is becoming rare there as the population is now fragmented, small and declining. Paperbark maple is one of the best small ornamental trees. Culture 77 Peeling, copper-brown bark 77 Leaves start orange in spring, then turn successively pinkish-brown, yellow and deep green through summer and finally turn deep red in autumn 77 Grows well in plant hardiness zones 6–8 77 Grows slowly to 25 feet or higher in full sun or part shade 77 May be half to equally as wide as it is tall 77 Prefers well-drained, moist, and preferably acid to neutral soil, but is fairly adaptable Concerns 77 Propagation is difficult because this species tends to produce sterile seeds 77 There are no major insect or disease problems 77 Do not plant in soils that are poorly drained or are frequently saturated Bartlett Management Practices WONDERS OF NATURE 77 Requires only moderate watering in dry weather Cauliflory 77 Allow room for the tree to spread 77 Mulch to the dripline when practical We expect to see flowers and fruit on a tree’s new 77 Minor structural pruning if necessary growth and leafy shoots. However, there are some trees that grow flowers and fruit directly on their trunks or main branches. This trait is called cauliflory, and the plants are cauliflorous. Cauliflorous plants are found primarily in tropical regions. There is one such plant, however, with which North Americans are familiar, the redbud tree. In case you wondered, the vegetable cauliflower is not cauliflorous! Compliments of

Get ready! Nature’s alarm clock is ringing. Trees and shrubs are waking up!

Worth a trip – University of North Carolina at Charlotte Botanical Gardens

The mission of the Charlotte Botanical Gardens, on the campus of the University of North Carolina, is to promote knowledge and appreciation of plants. It fulfills that goal wonderfully with three main areas to visit. The McMillan Greenhouse has six themed collections, eight greenhouse rooms, terraces, and a courtyard, and displays scenes from across the globe and through time. The Susie Harwood Garden features native and non-native plants that grow well within the Carolina Piedmont; it is designed to inspire visitors’ own gardening at home. The Van Landingham Glen, a woodland garden with hemlock and many other native plants, is a quiet space that recreates some of the Carolinas’ portion of the Appalachian Mountains. More information about visiting and events can be found at https://gardens.uncc.edu.

published by THE F. A. BARTLETT TREE EXPERT COMPANY (877) BARTLETT (877-227-8538) in U.S. and Canada • www.bartlett.com © 2018 The F. A. Bartlett Tree Expert Company For Tree Tips information contact [email protected] SE1