TREETREE TIPS& SHRUB CARE FROM BARTLETT EXPERTS TREE & SHRUB CARE FROM BARTLETT TREE EXPERTS

Molecular diagnostics — “CSI” for Ambrosia beetles by Christine Bechtel, Bartlett Laboratories Diagnostician grow gardens of fungus inside Some pathogens (organisms that Certain troublemakers are too small cause disease) are brilliant evaders to see even with a microscope. Others Ambrosia beetles are of detection, making them more will not grow in a petri dish, leave unique pests of trees dangerous than everyday pests such very little physical evidence of their because they attack as aphids and spider mites. They may presence, or cause rapid damage and kill trees, but are move incognito on to additional victims before their populations rise to a not interested in eating unless sophisticated testing is used to detectable level. In these instances, them, and they use unmask them. alcohol to find trees. Extracting genetic material from Molecular detection is a helpful tool Ambrosia beetles are a type of bark samples can help identify elusive in characterizing pathogens and pests beetle that bore deeply into trees pathogens and pests. that weaken or kill ornamental trees to grow fungi inside the tree. The and shrubs. Also, these techniques fungus “garden” is then used as extraction of genetic material (DNA or have greater sensitivity and reliability food for the larvae. Cellulose, the RNA) from the host sample, followed than other testing methods. Moreover, principal component of wood, is not by making millions of copies of the molecular testing can enhance a readily digested by insects, so fungi targeted gene through a process called diagnostician’s ability to detect invaders that can break down cellulose serve the polymerase chain reaction (PCR) in cases in which more traditional as the ambrosia (special food of the may be useful for identification. This techniques cannot. gods) for these beetles. technology is based on the discovery Bartlett Arborists send samples to our that certain lengths of DNA found in Many ambrosia beetles have specific Research Laboratories for diagnosis. marker genes are exclusive enough to symbiotic fungi that are unique to screen out non-target DNA (such as that species of beetle. The beetles from the host tree and ever-present Continued on page 2 bacteria), yet particular enough when sequenced, or decoded, to match to a pathogen or pest of interest. Continued on page 2 TREE & SHRUB MAINTENANCE CALENDAR

JUNE Be very aware of watering new lawns and Molecular diagnostics newly planted or transplanted shrubs, trees, etc. The best time to water is in early (Continued from page 1) morning to minimize fungal infestations Diseases that can be confirmed at the Diagnostic Clinic within the Bartlett Tree Cut back or pinch spent flowers to encourage new blooms Research Laboratory using molecular testing include bacterial leaf scorch, oak wilt, rose rosette virus, various wood decay fungi, elm yellows, Phoenix Palm Check for aphids and spider mites Decline, lethal yellowing of palm, and ash yellows. DNA from unknown fungi, Check for webworms on pecans and bacteria, insects, and oomycetes (water molds) can also be isolated, sequenced, mulberries and identified. Treat fire ant mounds as they develop As long as these disease pathogens evade detection, our not-so-“elementary” Check for bag worms on junipers, arborvitae methods will be vital for sleuthing out tree and shrub problems. and other evergreens

JULY Ambrosia beetles (Continued from page 1) Check crape myrtles for aphids

Check for spider mites even bring their own “seeds”, fungal Attacks in apparently ‘healthy’ trees spores actually, to start the garden. are becoming more frequent, although Check for scale, and treat if needed most attacks occur on trees with root Ambrosia beetles prefer to attack Check for lacebugs on azaleas and other injury or bleeding cankers. plants weakened and dying trees. They locate a stressed tree by the alcohol released Consult with your Bartlett Arborist Ensure irrigation is working properly. from the bark of the tree. Representative if you have noticed any Supplement new or tender plantings with of these risk factors in your landscape: hand-watering if needed Granulate ambrosia beetle, Xylosandrus 77 Flooding – Standing water in the root Watch for standing water in pots or crassiusculus, is one of the introduced containers—these are breeding grounds for species from Asia that have become zone of trees is dangerous if it lasts mosquitoes—treat standing water with a serious pests in North America. First longer than a few hours larvicide if container cannot be emptied discovered in the early 1970s in South 77 Bleeding cankers – These dark, wet splits in tree bark often release AUGUST Carolina, this species has spread across the United States as it attacks a alcohol, attracting ambrosia beetles Plant fall flowering perennials wide range of hosts (i.e., beech, oak, 77 Fine sawdust, or frass, from borers Finish planting warm season turfgrass if maple, fruit trees, and Chinese elm). entering a tree needed

Remove spent blooms to encourage reblooming Check for iron deficiencies in ornamental Fun with trees plants (interveinal chlorosis) Imaginative and funny Ensure irrigation is working correctly and leaf creations plants are staying properly watered A piece of paper, a few leaves, a glue stick and a marker are all you need to have a little fun with your child! Lay a leaf on a blank sheet of paper and let imagination take over; draw additions around the leaf to create all kinds of images. Save favorite ones by using a glue stick to fasten the leaf in place. TREE FOCUS: Texas ebony ( ebano)

History Texas ebony, a member of the nitrogen-fixing family, grows only in select portions of the country, primarily the desert Southwest, but makes a great street tree or shade tree and is ideal as a security hedge. It is a medium-sized tree, growing to a height of 35-80 feet with a spread of 20-30 feet at maturity. It has a dense crown of dark green with twice-pinnate leaves on uniquely twisting spiny branches. An evergreen, the Texas ebony keeps its leaves year-round and produces fragrant cream-colored blooms each spring. The seeds have been dried and made into jewelry. Its wood is very durable and used in fenceposts, but also has a rich grain prized in woodworking. Culture 77 Grows in acidic, alkaline, loamy, Once established the moist, sandy, well-drained, and Texas ebony can survive clay soils the driest conditions. 77 Prefers full sun 77 Needs care and watering when young, but can survive the driest conditions once established Concerns 77 Produces seedpods of approximately 3-6 inches in length, which drop from the tree and can create a mess in nearby driveways or walkways WONDERS OF NATURE 77 Bark can get sunburn if tree is overpruned A rainbow-colored tree! 77 No pests or diseases are The large, tropical tree Eucalyptus deglupta gets its of concern common name, rainbow eucalyptus, from its amazing Bartlett Management Practices multi-colored bark. Every year patches of the tree’s outer bark are shed at different times, in vertical strips, 77 Water newly planted trees thoroughly, every 7 to 10 days, for the first year revealing bright green new bark underneath. This bark changes color as it matures, so in 77 Prune low branches on landscape addition to the fresh green bark, there specimens until crown is at desired are streaks of blue, purple, orange and height, modifying the dense canopy maroon bark on the tree all at once! that grows to the ground in its natural form This tree thrives in tropical forests that get lots of rain. The colors of the bark 77 Avoid shearing the crown are not as intense when the rainbow eucalyptus grows outside its native range. Compliments of

It’s so easy being green when you have plant healthcare.

Caring for trees at Houston’s Hermann Park Hermann Park is considered by many to be Houston’s crown jewel. Millions of people visit every year. The park has a variety of attractions, including the world- class Houston Zoo, the Miller Outdoor Amphitheatre, the Japanese Garden, the Hermann Park Golf Course, and the latest multimillion dollar renovation—the stunning McGovern Centennial Gardens. Curating it all is the Hermann Park Conservancy, whose hardworking staff maintain the grounds every day of the year. Founded in 1992 as Friends of Hermann Park, Hermann Park Conservancy is a nonprofit citizens organization dedicated to the stewardship and improvement of Hermann Park. Bartlett’s Houston office has been providing both discounted and pro bono services at the Park since before 2007. When it became clear recently that four large live oaks adjacent to the Conservancy’s new offices were struggling in the aftermath of the work on the McGovern Centennial Gardens, Bartlett Arborist Representative Gene Basler was called in; he arranged Root Invigoration® treatments to help the four trees.

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] TX2