Dormant season pruning is like giving your trees and shrubs a strategic haircut while they're snoozing through winter. It's a vital practice for maintaining their health, shape, and vigor, and understanding the timing and seasonality is key to getting the most out of it.
Why prune during dormancy? Well, when plants are leafless, it's easier to see their structure and identify branches that need attention – those that are dead, diseased, crossing, or simply growing in an undesirable direction. Plus, the absence of leaves means less stress on the plant during the pruning process. Because the plant's energy is stored in its roots and trunk, it can focus on healing the pruning cuts efficiently come springtime, rather than expending energy on leaf production. This minimizes the risk of disease and promotes vigorous new growth when the weather warms.
So, when exactly is this magical dormant season? It generally falls between late autumn, after the leaves have dropped, and early spring, before new buds begin to swell. The specific timing, however, depends on your local climate and the type of plant you're pruning. For example, fruit trees like apple and pear are often pruned in late winter to minimize the risk of winter injury to freshly cut branches. Flowering shrubs, on the other hand, sometimes benefit from pruning just after they bloom in the spring, technically after dormancy, to avoid removing flower buds that have already formed.
Getting the timing right is crucial. Pruning too early can stimulate new growth that's vulnerable to frost damage. Pruning too late, after new growth has begun, can weaken the plant and reduce flowering or fruiting. A good rule of thumb is to wait until the coldest part of winter has passed but before you see any signs of new life.
Dormant season pruning isn't just about hacking away at branches. It's a thoughtful process that requires observation and an understanding of the plant's natural growth habit. By pruning correctly during this crucial period, you can encourage healthy growth, improve the appearance of your plants, and ensure they thrive for years to come.
Timing is everything, especially when it comes to interacting with the natural world. Consider pruning, a common gardening practice. While the general idea seems straightforward – snip off unwanted branches to encourage healthy growth – the reality is far more nuanced. Crucially, it involves understanding species-specific timing considerations. A blanket approach to pruning, ignoring the individual needs of different plants, can lead to disaster, stressing the plant, hindering its growth, or even killing it outright.
The concept of a dormant season is central to this discussion. Dormancy is a period of reduced metabolic activity, a kind of plant hibernation. For many deciduous trees and shrubs, this falls during the winter months. Pruning during dormancy offers several advantages. Firstly, the absence of leaves makes it easier to assess the plant's structure and identify branches that need removing. Secondly, with the plant's energy reserves focused on survival rather than active growth, pruning wounds heal more efficiently, reducing the risk of disease. Lastly, pruning during dormancy minimizes stress on the plant, as it's not actively pushing out new growth that would be lost in the process.
However, not all plants follow the same schedule. Some species, like spring-flowering shrubs, set their buds during the previous summer or fall. Pruning these plants during winter dormancy would remove the developing flower buds, resulting in a disappointing lack of blooms in the spring. For these species, the best time to prune is immediately after flowering, allowing ample time for new buds to form for the following year.
Similarly, certain trees, like maples and birches, are prone to "bleeding" sap if pruned in late winter or early spring. While not usually fatal, this sap loss can be unsightly and weaken the tree. Therefore, it's recommended to prune these species during the summer months or after the leaves have fallen in autumn.
Ultimately, successful pruning requires a species-specific approach. Consulting reputable resources like gardening books, local arborists, or horticultural extension services is essential to determine the optimal pruning time for your specific plants. By understanding and respecting the individual needs of each species, we can ensure healthy growth and vibrant blooms for years to come.
Summer pruning might seem counterintuitive. Aren't we supposed to prune when plants are asleep in winter? While dormant season pruning has its place, summer pruning offers a unique set of advantages and addresses specific objectives. It's all about understanding the nuances of plant growth and how timing affects the outcome.
One key difference lies in the plant's energy reserves. During dormancy, a plant stores energy in its roots and woody framework, ready for the spring burst of growth. Winter pruning capitalizes on this, encouraging vigorous new shoots come springtime. However, sometimes that vigorous growth is too vigorous. This is where summer pruning steps in.
By pruning during the growing season, you redirect the plant's energy. Instead of fueling rampant growth, you can shape the plant, remove unwanted suckers or water sprouts, and thin out congested branches. This allows for better air circulation and light penetration, reducing the risk of fungal diseases and improving fruit quality and size. Think of it as a mid-season course correction, refining the plant's form and focusing its energy where you want it.
Summer pruning also allows you to control the size of a plant without stimulating the explosive growth that can follow winter pruning. This is particularly useful for espaliered fruit trees, hedges, or any plant where you want to maintain a specific shape and size. It's a more controlled, measured approach.
However, summer pruning isn't suitable for all plants. Spring-flowering shrubs, for example, set their buds the previous year. Summer pruning would remove those buds, sacrificing the next year's blooms. It's crucial to understand the specific needs and growth habits of each plant before you prune.
While dormant season pruning focuses on rejuvenation and shaping the overall structure, summer pruning is about fine-tuning, directing energy, and maintaining control. Both techniques have their place in a gardener's toolkit, and knowing when and why to use each is key to a healthy and productive garden.
Pruning, while beneficial for tree health and structure, is essentially a controlled injury. Recognizing and responding to a tree's stress after pruning, particularly during the dormant season, is crucial for its long-term well-being. While dormant season pruning is often preferred as it minimizes sap loss and disease transmission, it doesn't mean the tree isn't experiencing stress. We just have to be more observant to see it.
Think of it like surgery – even a necessary one takes a toll. A tree pruned during dormancy might not show immediate signs of stress like wilting leaves, but it still needs time and resources to compartmentalize the pruning wounds and prepare for new growth in the spring. One key sign to watch for is delayed or reduced leaf emergence in the following spring. If the tree seems to be lagging behind its neighbors, it could be a sign of over-pruning or other stressors compounding the effects of the pruning cuts.
Another subtle clue is the appearance of the pruning wounds. Ideally, these wounds should be callusing over relatively quickly. Slow callus formation, or the presence of discoloration or decay around the wound, suggests the tree is struggling to heal. This could be due to improper pruning techniques, underlying disease, or environmental factors like drought stress.
So, how do we respond to these subtle signs of stress? First and foremost, patience is key. Don't panic and immediately start applying fertilizers or other treatments. Often, the best approach is to provide the tree with optimal growing conditions. Ensure adequate watering, especially during dry periods, and mulch around the base of the tree to conserve moisture and suppress weeds. Avoid excessive fertilization, as this can actually hinder the tree's natural healing processes.
If signs of stress persist or worsen, it's time to call in an arborist. They can diagnose the underlying issue and recommend appropriate treatments. Sometimes, it might be something as simple as adjusting watering practices. Other times, it could involve addressing a pest infestation or disease. The key takeaway here is that recognizing and responding to tree stress after dormant season pruning requires careful observation and a proactive approach to tree care. By understanding the subtle signs and providing the right support, we can help our trees recover quickly and thrive for years to come.
An arborist, or (less commonly) arboriculturist, is a professional in the practice of arboriculture, which is the cultivation, management, and study of individual trees, shrubs, vines, and other perennial woody plants in dendrology and horticulture.[citation needed]
Arborists generally focus on the health and safety of individual plants and trees, rather than managing forests or harvesting wood (silviculture or forestry). An arborist's scope of work is therefore distinct from that of either a forester or a logger.[citation needed]
In order for arborists to work near power wires, either additional training is required or they need to be certified as a Qualified Line Clearance Arborist or Utility Arborist (there may be different terminology for various countries). There is a variety of minimum distances that must be kept from power wires depending on voltage, however the common distance for low voltage lines in urban settings is 10 feet (about 3 metres).[1]
Arborists who climb (as not all do) can use a variety of techniques to ascend into the tree. The least invasive, and most popular technique used is to ascend on rope. There are two common methods of climbing, Single Rope System (SRS) and Moving Rope System (MRS). When personal safety is an issue, or the tree is being removed, arborists may use 'spikes', (also known as 'gaffs' or 'spurs') attached to their chainsaw boots with straps to ascend and work. Spikes wound the tree, leaving small holes where each step has been.[citation needed]
An arborist's work may involve very large and complex trees, or ecological communities and their abiotic components in the context of the landscape ecosystem. These may require monitoring and treatment to ensure they are healthy, safe, and suitable to property owners or community standards. This work may include some or all of the following: planting; transplanting; pruning; structural support; preventing, or diagnosing and treating phytopathology or parasitism; preventing or interrupting grazing or predation; installing lightning protection; and removing vegetation deemed as hazardous, an invasive species, a disease vector, or a weed.[citation needed]
Arborists may also plan, consult, write reports and give legal testimony. While some aspects of this work are done on the ground or in an office, much of it is done by arborists who perform tree services and who climb the trees with ropes, harnesses and other equipment. Lifts and cranes may be used too. The work of all arborists is not the same. Some may just provide a consulting service; others may perform climbing, pruning and planting: whilst others may provide a combination of all of these services.[2]
Arborists gain qualifications to practice arboriculture in a variety of ways and some arborists are more qualified than others. Experience working safely and effectively in and around trees is essential. Arborists tend to specialize in one or more disciplines of arboriculture, such as diagnosis and treatment of pests, diseases and nutritional deficiencies in trees, climbing and pruning, cabling and lightning protection, or consultation and report writing. All these disciplines are related to one another and some arborists are very well experienced in all areas of tree work, however not all arborists have the training or experience to properly practice every discipline.[citation needed]
Arborists choose to pursue formal certification, which is available in some countries and varies somewhat by location. An arborist who holds certification in one or more disciplines may be expected to participate in rigorous continuing education requirements to ensure constant improvement of skills and techniques.[citation needed]
In Australia, arboricultural education and training are streamlined countrywide through a multi-disciplinary vocational education, training, and qualification authority called the Australian Qualifications Framework, which offers varying levels of professional qualification. Government institutions including Technical and Further Education TAFE offer Certificate III or a diploma in arboriculture as well as some universities.[3][4] There are also many private institutions covering similar educational framework in each state. Recognition of prior learning is also an option for practicing arborists with 10 or more years of experience with no prior formal training. It allows them to be assessed and fast track their certification.[citation needed]
In France, a qualified arborist must hold a Management of Ornamental Trees certificate, and a qualified arborist climber must hold a Pruning and Care of Trees certificate; both delivered by the French Ministry of Agriculture.[5][6]
In the UK, an arborist can gain qualifications up to and including a master's degree. College-based courses include further education qualifications, such as national certificate, national diploma, while higher education courses in arboriculture include foundation degree, bachelor's degree and master's degree.[citation needed]
In the US, a Certified Arborist (CA) is a professional who has over three years of documented and verified experience and has passed a rigorous written test from the International Society of Arboriculture. Other designations include Municipal Specialist, Utility Specialist and Board Certified Master Arborist (BCMA). The USA and Canada additionally have college-based training which, if passed, will give the certificate of Qualified Arborist. The Qualified Arborist can then be used to offset partial experience towards the Certified Arborist.
Tree Risk Assessment Qualified credential (TRAQ), designed by the International Society of Arboriculture, was launched in 2013. At that time people holding the TRACE credential were transferred over to the TRAQ credential.[citation needed]
In Canada, there are provincially governed apprenticeship programs that allow arborists' to work near power lines upon completion. These apprenticeship programs must meet the provincial reregulations (For example, in B.C. they must meet WorkSafeBC G19.30), and individuals must ensure they meet the requirements of the owner of the power system.[citation needed]
Trees in urban landscape settings are often subject to disturbances, whether human or natural, both above and below ground. They may require care to improve their chances of survival following damage from either biotic or abiotic causes. Arborists can provide appropriate solutions, such as pruning trees for health and good structure, for aesthetic reasons, and to permit people to walk under them (a technique often referred to as "crown raising"), or to keep them away from wires, fences and buildings (a technique referred to as "crown reduction").[7] Timing and methods of treatment depend on the species of tree and the purpose of the work. To determine the best practices, a thorough knowledge of local species and environments is essential.[citation needed]
There can be a vast difference between the techniques and practices of professional arborists and those of inadequately trained tree workers. Some commonly offered "services" are considered unacceptable by modern arboricultural standards and may seriously damage, disfigure, weaken, or even kill trees. One such example is tree topping, lopping, or "hat-racking", where entire tops of trees or main stems are removed, generally by cross-cutting the main stem(s) or leaders, leaving large unsightly stubs. Trees that manage to survive such treatment are left prone to a spectrum of detrimental effects, including vigorous but weakly attached regrowth, pest susceptibility, pathogen intrusion, and internal decay.[8]
Pruning should only be done with a specific purpose in mind. Every cut is a wound, and every leaf lost is removal of photosynthetic potential. Proper pruning can be helpful in many ways, but should always be done with the minimum amount of live tissue removed.[9]
In recent years, research has proven that wound dressings such as paint, tar or other coverings are unnecessary and may harm trees. The coverings may encourage growth of decay-causing fungi. Proper pruning, by cutting through branches at the right location, can do more to limit decay than wound dressing [10]
Chemicals can be applied to trees for insect or disease control through soil application, stem injections or spraying. Compacted or disturbed soils can be improved in various ways.[citation needed]
Arborists can also assess trees to determine the health, structure, safety or feasibility within a landscape and in proximity to humans. Modern arboriculture has progressed in technology and sophistication from practices of the past. Many current practices are based on knowledge gained through recent research, including that of Alex Shigo, considered one "father" of modern arboriculture.[11]
Depending on the jurisdiction, there may be a number of legal issues surrounding the practices of arborists, including boundary issues, public safety issues, "heritage" trees of community value, and "neighbour" issues such as ownership, obstruction of views, impacts of roots crossing boundaries, nuisance problems, disease or insect quarantines, and safety of nearby trees or plants that may be affected.[citation needed]
Arborists are frequently consulted to establish the factual basis of disputes involving trees, or by private property owners seeking to avoid legal liability through the duty of care.[12] Arborists may be asked to assess the value of a tree[13] in the process of an insurance claim for trees damaged or destroyed,[14] or to recover damages resulting from tree theft or vandalism.[15] In cities with tree preservation orders an arborist's evaluation of tree hazard may be required before a property owner may remove a tree, or to assure the protection of trees in development plans and during construction operations. Carrying out work on protected trees and hedges is illegal without express permission from local authorities,[16] and can result in legal action including fines.[17] Homeowners who have entered into contracts with a Homeowner's association (see also Restrictive covenants) may need an arborists' professional opinion of a hazardous condition prior to removing a tree, or may be obligated to assure the protection of the views of neighboring properties prior to planting a tree or in the course of pruning.[18] Arborists may be consulted in forensic investigations where the evidence of a crime can be determined within the growth rings of a tree, for example. Arborists may be engaged by one member of a dispute in order to identify factual information about trees useful to that member of the dispute, or they can be engaged as an expert witness providing unbiased scientific knowledge in a court case. Homeowners associations seeking to write restrictive covenants, or legislative bodies seeking to write laws involving trees, may seek the counsel of arborists in order to avoid future difficulties.[19]
Before undertaking works in the UK, arborists have a legal responsibility to survey trees for wildlife, especially bats, which are given particular legal protection. In addition, any tree in the UK can be covered by a tree preservation order and it is illegal to conduct any work on a tree, including deadwooding or pruning, before permission has been sought from the local council.[citation needed]
The protagonist in Italo Calvino's novel The Baron in the Trees lives life on the ground as a boy and spends the rest of his life swinging from tree to tree in the Italian countryside. As a young man he helps the local fruit farmers by pruning their trees.[citation needed]
Some noteworthy arborists include:
Arboriculture (/ˈɑËÂÂrbÉ™rɪˌkÊŒltʃər, É‘ËÂÂrˈbÉâ€ÂËÂÂr-/)[1] is the cultivation, management, and study of individual trees, shrubs, vines, and other perennial woody plants. The science of arboriculture studies how these plants grow and respond to cultural practices and to their environment. The practice of arboriculture includes cultural techniques such as selection, planting, training, fertilization, pest and pathogen control, pruning, shaping, and removal.
A person who practices or studies arboriculture can be termed an arborist or an arboriculturist. A tree surgeon is more typically someone who is trained in the physical maintenance and manipulation of trees and therefore more a part of the arboriculture process rather than an arborist. Risk management, legal issues, and aesthetic considerations have come to play prominent roles in the practice of arboriculture. Businesses often need to hire arboriculturists to complete "tree hazard surveys" and generally manage the trees on-site to fulfill occupational safety and health obligations.[citation needed]
Arboriculture is primarily focused on individual woody plants and trees maintained for permanent landscape and amenity purposes, usually in gardens, parks or other populated settings, by arborists, for the enjoyment, protection, and benefit of people.[citation needed]
Arboricultural matters are also considered to be within the practice of urban forestry yet the clear and separate divisions are not distinct or discreet.[citation needed]
Tree benefits are the economic, ecological, social and aesthetic use, function purpose, or services of a tree (or group of trees), in its situational context in the landscape.
A tree defect is any feature, condition, or deformity of a tree that indicates weak structure or instability that could contribute to tree failure.
Common types of tree defects:
Codominant stems: two or more stems that grow upward from a single point of origin and compete with one another.
Included bark: bark is incorporated in the joint between two limbs, creating a weak attachment
Dead, diseased, or broken branches:
Cracks
Cavity and hollows: sunken or open areas wherein a tree has suffered injury followed by decay. Further indications include: fungal fruiting structures, insect or animal nests.
Lean: a lean of more than 40% from vertical presents a risk of tree failure
Taper: change in diameter over the length of trunks branches and roots
Epicormic branches (water sprouts in canopy or suckers from root system): often grow in response to major damage or excessive pruning
Roots:
Proper tree installation ensures the long-term viability of the tree and reduces the risk of tree failure.
Quality nursery stock must be used. There must be no visible damage or sign of disease. Ideally the tree should have good crown structure. A healthy root ball should not have circling roots and new fibrous roots should be present at the soil perimeter. Girdling or circling roots should be pruned out. Excess soil above the root flare should be removed immediately, since it presents a risk of disease ingress into the trunk.
Appropriate time of year to plant: generally fall or early spring in temperate regions of the northern hemisphere.
Planting hole: the planting hole should be 3 times the width of the root ball. The hole should be dug deep enough that when the root ball is placed on the substrate, the root flare is 3–5cm above the surrounding soil grade. If soil is left against the trunk, it may lead to bark, cambium and wood decay. Angular sides to the planting hole will encourage roots to grow radially from the trunk, rather than circling the planting hole. In urban settings, soil preparation may include the use of:
Tree wells: a zone of mulch can be installed around the tree trunk to: limit root zone competition (from turf or weeds), reduce soil compaction, improve soil structure, conserve moisture, and keep lawn equipment at a distance. No more than 5–10cm of mulch should be used to avoid suffocating the roots. Mulch must be kept approximately 20cm from the trunk to avoid burying the root flare. With city trees additional tree well preparation includes:
Tree grates/grill and frames: limit compaction on root zone and mechanical damage to roots and trunk
Root barriers: forces roots to grow down under surface asphalt/concrete/pavers to limit infrastructure damage from roots
Staking: newly planted, immature trees should be staked for one growing season to allow for the root system to establish. Staking for longer than one season should only be considered in situations where the root system has failed to establish sufficient structural support. Guy wires can be used for larger, newly planted trees. Care must be used to avoid stem girdling from the support system ties.
Irrigation: irrigation infrastructure may be installed to ensure a regular water supply throughout the lifetime of the tree. Wicking beds are an underground reservoir from which water is wicked into soil. Watering bags may be temporarily installed around tree stakes to provide water until the root system becomes established. Permeable paving allows for water infiltration in paved urban settings, such as parks and walkways.
Within the United Kingdom trees are considered as a material consideration within the town planning system and may be conserved as amenity landscape[2] features.
The role of the Arborist or Local Government Arboricultural Officer is likely to have a great effect on such matters. Identification of trees of high quality which may have extensive longevity is a key element in the preservation of trees.
Urban and rural trees may benefit from statutory protection under the Town and Country Planning[3] system. Such protection can result in the conservation and improvement of the urban forest as well as rural settlements.
Historically the profession divides into the operational and professional areas. These might be further subdivided into the private and public sectors. The profession is broadly considered as having one trade body known as the Arboricultural Association, although the Institute of Chartered Foresters offers a route for professional recognition and chartered arboriculturist status.
The qualifications associated with the industry range from vocational to Doctorate. Arboriculture is a comparatively young industry.