Oak Tree Pruning Practices
Live Oak Tree Pruning You live in one of the most scenic neighborhoods in the Texas Hill Country, known for our beautiful homes,and our majestic Oaks. Our live oak trees are our neighborhoods crowning glory. So, preserving and caring for them is extremely important to your landscape values and their beauty. One might say, our live oaks eke a survival out of Texas because of the extreme harsh climate and soil conditions in which they must live, and yes they thrive in spite of our latest extended drought conditions. Our Live Oaks around homes and cities require certain conditions to survive and prosper. The homeowner should be concerned regarding the landscape activities of planting near oaks, irrigation and feeding, pruning, disease and insect infestations. Most native oaks in Texas evolved and prospered in an environment typified by a cool, moist winters and hot, dry summers. Under natural conditions, surface soils are wet during the cooler months and become dry by summer. Natural vegetation growing around and beneath oaks are usually dormant during the winter and flourishes during spring and by late summer, and into early fall creating the well-known golden-brown landscape, of Texas' valleys and foothills. Native live oaks, however, remain green because their thick, leathery leaves and other adaptive features reduce their growth rate and water use. The homeowners should attempt to approximate the natural environment in which these magnificent trees are in their natural setting. When cared for properly, live oak has a moderately rapid to slow rate of growth. SOUTHERN LIVE OAK (Quercus virginiana) - A large, sprawling, picturesque tree and it is highly desirable as a landscape tree. The Live Oak is one of the broadest spreading of the Oaks, providing large areas of deep, inviting shade. Reaching 40 to 60 feet in height with a 60 to 100 foot spread and usually possessing many sinuously curved trunks and branches. Live Oak is an impressive sight for any large-scaled landscape. Give it plenty of room since the trunk can grow to more than six feet in diameter. An amazingly durable American native, it can measure its life in centuries if properly located and cared for in the landscape. In Texas, live oaks learned ten thousand years ago that Texas soils and environmental conditions are not conducive for propagation from the acorns. They depend on animals and birds to transplant acorns away from the parent tree for the sake of forest diversity. Live oaks are very bad parents and do not want competition from their siblings, so they predispose a fungus to kill the germination of the acorns that remain under the tree. Live oaks propagate in a very unusual manner, they put out ramets (sending-up root sprouts) from the mature roots, or otherwise a bud that grows off the root. This method ensures 100% survival as the new shoots have a fully mature root system for support. They actually clone themselves, a Mott or grove of a few or up to hundreds of trees are really all the same tree and can cover large acreage areas. Planting Near Oaks Only drought-tolerant plants that require no summer water should be planted around old established oaks and they should be planted 6' from the base of the tree. DO NOT plant exotic grasses, ivy, or other vegetation requiring summer irrigation near them. Irrigating and Fertilizing Native live oaks usually do not require measurable amounts of irrigation, however they usually thrive in our suburban landscapes if properly cared for. Healthy live oaks are even able to survive the excessively dry summers. Frequent, shallow watering not only encourages crown and root rot, it results in ineffective shallow roots near the surface. Under no circumstances should the ground near the base of a live oak be allowed to become moist during warm periods. Deep watering at the critical root zone, which the drip edge and outward is far more effective and responsible. Mature trees usually need little supplemental nutrient replacement. Fertilization should be done only to maintain vigor and if growth is poor. Lighter and frequent applications will produce better results and allow the trees to grow at a more natural and slow rate. Heavy fertilization will create rapid, lush growth, which is a loud dinner bell for insects and other disease. Excessive fertilization causes the tree to divert its defense energy against disease and insects, to growth. Trees that have recently undergone severe pruning or root damage should not be fertilized for at least six months. Pruning Pruning should be done only during the hottest time of year, late June to October and the coldest time, late November to mid February for the evergreen species of oaks. . Keep in mind that the canopy and root system must always be kept in balance, moderation is the best policy as excessive pruning may well jeopardize the tree’s overall vigor and health. Some research has shown that, wound dressings or sealing compounds tree paint do more harm than good. Yet all tree companys use a wound sealer and I seal all cuts to be on the safe side. Because of the risk of oak wilt,an inexpensive Black spray paint is best applied to seal the wound and at the same time allow the wood tissue to cure properly. Pruning should be performed by an experienced arborist or homeowner familiar with oak pruning according to the pruning standard of the Texas Chapter of the International Society of Arboriculture. "Pruning Notes" Recognizing Live Oak Pruning maintainance needs and susceptable tree health issues. All Dead Live Oaks should be removed immediately upon decline. Most Oaks develop mechanical growth problems which can be caused by self inflicted wounding {rubbing/Branch crossing,abrasions) usually due to neglect which can become a haven for insects,usually ants or a potential disease infection or branch transmission point. This includes interlocking limbs that rub against each other, prune, remove,repair and seal these issues ASAP. Dead wood must be removed usually with a small top handle arborist chainsaw( Echo,Stihl,or Shindaiwa) by making a smooth flush cut above the dead branch paralell to the main branch. A relief cut above dead branch intersection can reduce weight and pressure and prevent the cut and bark from tearing on medium to large limbs Then immediatly seal the cut with tree-cote or a thick coat of cheap black spray paint. Remember safety is most important and use ropes and relief cuts to prevent binding, Also to secure large branches and be sure of your exit and use a tree safety harness as needed for high work and good common sense will ensure a successful and safe job. Branches rubbing on roofs,other branches or other structures must be cut back as the abrasion is a potential insect disease transmission point. This will significantly reduce the possibility of Oak Wilt wound infection by reducing insect vector transmission points. Trees growing up into and possibly rubbing other branches through the dome or crown of other susceptible Live Oaks. This type of abrasive wounding, will never heal, and will flow sap year around. The flow will be heaviest during peak insect and fungal mat formation periods. All pruning cuts made by man, even large or incompetent cuts, will stop flowing sap within a couple of hours. If these wounds are properly treated with pruning paint, there will be no sap flow at all and the wound will be unattractive to the insect. Therefore, properly pruned Oaks are less likely to become infected by sap feeding insects. 1. Trees that need to be pruned, should be pruned, by a educated tree savy homeowner familiar with safe oak tree pruning practices or experienced pruner or professional Arborist, as soon as possible. Removing all smaller lower and dead branches will help push the growth to the upper branches ands provide better growth structure to the upper canopy and enhance overall tree health. Overall Live Oak tree health will improve the overhead canopy as the trees "Dome Out" and growth will improve branch health structure by allowing denser growth. 2. Try to avoid leaving knobs sticking out as they are unsightly and susceptable to decay and insects love these places. Flush Cut and seal all knobs and wounds ASAP. 3. When pruning trees of deadwood, cuts susceptible to decay and or harboring insects(usually ants)always remove the safe harbor by eliminating the facilitation and transmission vehicle points of disease infection to the trees. 4. Always use a non-phytotoxic wound sealer such as tree-cote or paint should always be used on every cut ASAP. Diseases and Insects Native Texas live oaks are relatively tolerant of most diseases. In early spring, timed at leaf out, live oaks can be attacked by a barrage of leaf eating insects. The cankerworm and leaf rollers are the most common predators and can literally defoliate a tree over night. However, using a safe foliar application of Bt (a Bio-pesticide) can keep them under control. It is most unfortunate, they are subject to OAK WILT which has devastated many trees in parts of central Texas. Studies have shown that they can be replanted successfully in old and developing oak wilt centers. Precautions must be taken to prevent wounding. Wounds attract sap feeding beetles that carry the oak wilt fungus spores. If the tree is wounded or it has to be pruned, immediately paint with a light application of spray paint. The light dressing application of paint forms an insect barrier and allows the wound wood to properly cure. Diseases and other problems when over watered or improperly pruned attack trees weakened by disturbance or improper care. Disease infected trees decline slowly over a period of years if not attended to. However, if oak wilt and other diseases are caught in the early stages, a tree can be saved. Early diagnosis and comprehensive treatment is best left to a qualified arborist. Major foliage diseases of live oaks are: oak leaf blister, twig borers, diplodia (twig fungus), anthracnose and powdery mildew. Seldom do these diseases become severe enough to require treatment. Soil Compaction and Trenching The root zone or rhizophere under a tree is like a fresh piece of baked bread, it contains all the caterpillars, gases (oxygen, hydrogen and nitrogen) moisture, microbial life and nutrients. When compacted or squeezed flat like a tortilla, all the gases, moisture and nutrients are no longer available. This soil compaction under a tree can cause serious root damage and crown loss over extended time. Contractors should take all necessary precautions to protect trees during construction and many trees are two and three hundred years old and can never be replaced. In all my years, I have never been able to place a significant value on a near 400 year old live oak tree. This is priceless! An eight year old boy summed it all up... " That is a non-renewable resourse of energy" !!!!! That changed my attitude! Trenching near the critical root zone is often overlooked as a cause of tree death. Trenching usually occurs when underground utilities are installed. Digging a trench within the root zone can severe a significant portion of a tree's roots and cause damage to the tree. Ninety five percent of all tree roots are within the top 12 to 16 inches of the surface soils and can extend three times beyond the drip edge. Landscape Paving, and Landscape Fill Around Oak Trees Paving can cause the same problems associated with soil compaction. Paving prevents water from soaking the soil and impedes the exchange of gases between roots, soil and the atmosphere. Excessive moisture trapped by fill material can also cause root and crown rot. It is best to avoid tampering with the natural grade, or to leave the natural grade within the root zone alone and use retaining walls. Poor drainage is a common cause of oak tree deaths as adequate drainage is critical to ensure a proper balance of moisture, air and nutrients to grown and survive. Live Oak (Quercus virginiana and Q. fusiformis) are widely adapted species. In addition there are numerous hybrids between the two species. They provide shade during the winter as well as summer months. Leaf shed is during the early spring and trees will be completely defoliated for only a few weeks, at which time replacing new leaves and blossoms simultaneously This is why it is known as an evergreen oak. The live oak tree tolerates a variety extremes, from of high acid soils and climate conditions extending from Virginia down along the east coast to Florida. They tolerate salt conditions and extend across the coastal plains and into the rocky hill country in South Central Texas with high alkaline soils, and hot dry summer heat. They extend west to California for the cools moist winters and hot dry summers. That is our majestic Live Oak Tree Live Oaks, can get Oak Wilt by way of root transmission from another Live Oak, or from the sap feeding, Nitidulide beetle. This insect would first have to have fed from a tree with an infected fungal mat. A fungal spore can stick to its body, then be carried to the next tree that the insect feeds upon. Red Oaks are the most common tree to produce this infected fungal mat. Insect transmission does not occur from Live Oak to Live Oak as Live Oaks are incapable of producing the infected fungal mat and fungal spore. When Oak Wilt travels through the grafted root system of Live Oaks, it is at a rate of about 75 feet per year. Spread at a rate of 150 feet per year has been documented. Spanish/Red Oaks primarily get Oak Wilt by insect transfer. Spanish/Red Oaks do not develop grafted root systems. Furthermore, Spanish/Red Oaks are one of the few trees known to produce the infected fungal mat and fungal spore, that can be transported by way of sap feeding beetles. This infected fungal mat most commonly forms in mild temperatures, for the first year following the trees death from Oak Wilt. Spanish/Red Oaks can not be salvaged once they have contracted the disease. "Another Helpful Oak Tree Pruning Link" "Digital Arborist" Double Click around the Broken Weather Link |  |
