We Asked Arborists When to Prune Dogwood Trees, and They All Said the Same Thing
The Spruce – Heather Zidack and other professionals give their insight on pruning Dogwood Trees
Yard Maintenance
Celebrate Arbor Day!
By Dawn Pettinelli, UConn Home & Garden Education Center
Arbor Day is celebrated in Connecticut on April 25th. Since it is a day traditionally set aside for the planting of trees, perhaps you might consider adding one to your home landscape. If you haven’t the need for another arboreal specimen, then plan on giving your existing trees a little TLC.
Trees have a lot to offer. They provide us with cool shade on hot summer days, brighten our spring season with lovely blossoms, add color to the fall landscape and winter interest throughout cold, dreary days. Trees provide food, nesting sites and shelter for many animals, especially birds. They help reduce noise pollution, trap particulate air pollutants, and can alter the microclimate surrounding them.
Most importantly, trees supply plenty of oxygen for us to breathe. Each year, an acre of trees produces enough oxygen to keep 18 people alive. They also sequester carbon dioxide. Trees convert atmospheric carbon dioxide into plant matter as they photosynthesize. This has important consequences worldwide. As more and more of our forested land is being cleared, less carbon dioxide can be stored in trees and more is available to increase the atmospheric carbon dioxide levels which, in turn, can contribute to global warming.
While we can’t stop global deforestation, we can make a difference in our own backyards by planting more trees or making sure that the trees already present receive the conditions they need to thrive.
When selecting a tree for your landscape, do consider factors like its ultimate height and spread, susceptibility to insect and disease problems, flowering, fruiting and fall foliage potential, rate of growth and site requirements. Review gardening books, consult with nurserymen and maybe visit an arboretum to view mature specimens.
Trees are purchased either as dormant stock through mail order sources, containerized, or balled-and-burlapped (B & B). Dormant trees generally arrive in the spring or fall and should be soaked for a couple of hours and planted immediately. If you can’t get them in the ground right away, they can be stored in a cool place for a few days out of direct sunlight. Make sure them are kept moist.
Containerized stock can be planted throughout the growing season although cooler spring or fall is best. Hard to transplant species are best purchased this way as there is less disruption to their root system. If potbound, make several vertical cuts about one-quarter inch deep around the root ball before planting.
Purchasing B & B trees is fine for younger specimens, but often larger trees have a good portion of their roots removed in this process. This can lead to poor survival. For greatest success, choose small to medium sized trees.
Holes for planting only need be as deep as the root system. The key is to make them at least 2 feet wider than the root ball. Especially in heavy or compacted soils, be sure to
loosen as much soil around the planting area as possible so roots can grow freely. The majority of roots are found in the upper 3 feet of soil.
Amendments such as peat moss or fertilizer are not necessary to add to the backfill. However, if the soil pH or phosphorus levels are low, ground limestone and bonemeal can be mixed into the backfill.
Add water to the hole before planting and let it drain. Next, position the root ball. Remove plastic mesh and cords. Burlap can be cut away as much as possible. Fill in the hole about half way. Gently firm the soil around the root ball. Don’t stomp on it or you will compact the soil. Water thoroughly and when the water drains, finish filling the hole. Make a well around the tree with soil and water once more. Apply a 2 to 3 inch layer of mulch keeping it away from the trunk. Newly planted trees need a thorough soaking each week throughout the first growing season either from natural precipitation or from you.
If you have questions about trees or any other gardening topic, call the UCONN Home & Garden Education Center (toll-free) at (877) 486-6271 or email us at ladybug@uconn.edu or visit our website, www.homegarden.cahnr.uconn.edu.
Preparing for Spring on CRIS Radio
Is Early Leaf Drop an Indicator of Tree Health?
By Nick Goltz, DPM, UConn Home & Garden Education Center, Plant Diagnostic Lab
The autumnal equinox, one of two times of the year at which day and night are equal in length, just passed on Sunday the 22nd. While this point marks the astrological start of fall, many of the trees lining the roads on my drive to work (and in many of our clients’ yards) seem to want to get a head start on the season. Since late August, we’ve been getting calls from folks across Connecticut asking why the leaves on their trees are changing color and falling early. You may even be thinking, “Hey, a few of my trees are dropping their leaves early too. Is that something that can indicate how healthy they are?” In a word, maybe!
First, let me share the good news that, for most trees, premature color change and leaf drop doesn’t mean that they are in any immediate danger. Plants, much like humans and other animals, respond to stress differently depending on their environment and the kind of year they’ve been having. Just like we might see a little hair loss after a particularly stressful few months, trees may drop their leaves early as a response to stress. Identifying what is causing the stress however, is important when deciding if concern is warranted.
What type of stressors might be causing this early color change and leaf drop? For most trees, the answer is water. Connecticut and several other states in New England had a series of heavy rain events and flash flooding throughout the summer. While we’ve had hardly any rain in the land of steady habits for several weeks now, for many trees, the damage has already been done and symptoms are just appearing now. Saturated soils deprived plant roots of oxygen, damaging them and making them more susceptible to disease. Plants in especially low-lying areas, caught in floodwaters, or grown in poorly-draining clay soils likely experienced the most damage and earliest leaf drop. Some plants may have even perished outright from the damage. Besides water, excessive heat and the increased prevalence of fungal and bacterial diseases, as well as some insect pests, may have also contributed to the stress our plants are letting us know about now.
So, how can you know if the early color change or leaf drop is an issue for your favorite tree or just its way of complaining about a stressful summer? When and where the leaf change and drop is occurring can help you determine if the damage is likely a normal stress response or due to something more sinister.
Consider when the color change and leaf drop first began. In this instance, seeing some leaves begin to change in the last week of August is less concerning than seeing them change at the end of June. Plants that have their leaves change color and drop in midsummer or earlier are most likely dealing with a disease or pest issue, rather than a stress response. I recommend you get advice for these plants by contacting the UConn Home & Garden Education Center and remove them from your garden if they are unlikely to recover.
Also, consider what part(s) of the canopy was affected. Conifers such as white pine drop their leaves (we usually call them needles) in response to stress too, but you will typically see this take place on the interior of the plant – the older needles that aren’t capturing much sun anymore. Branches on deciduous trees, such as oak, that are in shady spots tend to drop their leaves early too, and this is normal.
Branches in full sun that lose their leaves very early, while others on the tree remain fine, are a bit suspicious. Mark these branches with tape or string and monitor them carefully as the plant produces its first leaves or flowers in the spring. If these marked branches do not produce leaves or flowers with the rest of the tree, get advice (again, by contacting the folks at the UConn HGEC)! The best option is usually to cut them close to the main trunk, then disinfect your pruning tools.
If you’re concerned about the health of your tree, including as a result of a potential disease or pest issue, practice good fall habits to give your trees the best foot forward next spring! Clean as much leaf litter as possible and remove it from the base of trees that dropped their leaves early. If you suspect the plant is diseased or has pests, throw away these leaves or burn them before composting. For example, many plant pathogenic fungi can survive the winter on fallen leaves and reinfect healthy plant tissue the following spring. It’s also a good idea to minimize added stress for your plants. Try not to expose them to herbicides, deicing salts, fertilizers, or other chemicals until they’re looking strong again.
If you aren’t sure how to proceed with your fall cleanup or if you’d simply like a second opinion on your favorite tree, get free horticultural consultation from the UConn Home & Garden Education Center by emailing ladybug@uconn.edu or by calling (877) 486-6271.
Time to Fertilize Your Lawn
By Dawn Pettinelli, UConn Home & Garden Education Center
While September brings with it shorter days, we still have plenty of opportunities to attend to those fall yard and garden chores. Among them is applying fertilizer to lawns. Keep in mind that for the most part, our lawns consist of cool season grasses. In a more typical year, turfgrass growth slows down during dry, hot summer weather. Up until the past few weeks, this summer had seen enough rainfall to keep lawns green and growing.
Turf plants take up nutrients as they grow and these need to be occasionally replenished. September through mid-October is a perfect time to do so as the cooler temperatures stimulate shoot and root growth and hopefully, some gentle fall rains will help the nutrients infiltrate the soil and reach the roots.
So, what kind and how much fertilizer does one need? Of course, the best way to determine that is with a soil test (www.soiltesting.cahnr.uconn.edu) but without a soil test, follow the directions on the fertilizer package. Whether one chooses a natural/organic or a synthetic fertilizer is up to the individual. A 2024 National Lawn Fertilizer Study by Axiom, found that 95% of respondents said it was important to apply fertilizers that are safe for children, pets and the environment. Somewhat ironically, despite safety concerns, 67% have used fertilizers that contain weed killers or insecticides. In most cases, applications of any kind of pesticide, whether it be an herbicide, insecticide or fungicide are not necessary at this time of year.
Most folks who tend lawns or gardens are aware that fertilizer packages come with a guaranteed analysis. These are the 3 numbers on the package, for example 5-10-10. They are always in the same order and always stand for the percent by dry weight of total nitrogen, phosphorus and potassium. Unless you are purchasing a lawn starter fertilizer, which you would use for new seedings and soddings, you will notice that maintenance lawn fertilizers sold in Connecticut have 0 as a middle number, so for instance 18- 0- 4.
This is because of phosphorus legislation passed in 2013. Many people may not be aware that phosphorus is the number one inland freshwater pollutant in the state and when it enters streams, rivers, ponds or lakes, it encourages algae growth that eventually dies and decomposes depleting the oxygen in the water and leading to fish kills. Also, it may encourage the growth of toxic cyanobacteria as well as making the waters undesirable for recreational activities. In a nutshell, the law says that phosphorus should not be applied to an established lawn unless a soil test performed in the past 2 years provides a recommendation for phosphorus.
When applying a lawn fertilizer, either the soil test recommendations or the ones on the package call for approximately 1 pound of nitrogen to be applied for every 1000 square feet of lawn. Two things to check are the size of your lawn and also, the setting on your spreader.
Ideally one would like to apply the fertilizer when the grass is dry but before a light rain. If no rain is predicted, it would be beneficial if the lawn was watered lightly so that fertilizer prills are not sticking to the blades of grass but washed into the soil.
Lawn fertilizers generally are available as either fast or slow release. The nutrients in fast release fertilizers, especially nitrogen, are generally water soluble and readily available to your lawn grasses. Many lawn fertilizers also contain slow release or water insoluble forms of nitrogen. These are typically more expensive but supply nitrogen over longer periods of time. They are less likely to burn and more slowly fertilize plants.
Whichever one you pick; it should be put down by October 15th. Weather is unpredictable after that, and plants may or may not be able to use the nutrients before colder temperatures prevail and grass growth slows.
This time of year is great for reseeding any bare spots, topdressing with compost if organic matter levels are low, using a mulching mower to incorporate leaves as they fall and for aerating if the soil is compacted. Send your lawn questions to ladybug@uconn.edu or call the UConn Home & Garden Education Center with your queries at (877) 486-6271.
Calling the Cut – Tree Triage, Care, and Removal
By Nick Goltz, DPM, UConn Plant Diagnostic Lab/UConn Home & Garden Education Center
The forecast is looking good for a perfect 4th of July weekend. Most folks will take advantage of the weather ahead to plan that perfect grilling menu for when their friends and family visit. This is a much-needed respite from the severe weather that passed through over the past few weeks. Severe winds and torrential rains hammered Connecticut and most of the rest of the Northeast after a recent heat wave. With the weather for the week ahead of us is looking much better than the weather of the week behind us, now is the perfect time to assess our trees and determine if any action needs to be taken before the next storm comes!
I’ll start and end this column with the advice that a professional arborist should be called-in if you are ever unsure of your tree’s health, or if you need support regarding safe management and potential removal. In Connecticut, one of the best resources for finding a licensed, local arborist as well as additional resources regarding tree care and maintenance can be found on the Connecticut Tree Protective Association website, ctpa.org. That said, tree triage can start with you at home. There are many things one can be on the lookout for to determine if a tree need professional attention, and potentially in what order the work should be done.
I’m sure you’ve heard this phrase used to describe real estate, but with trees too, location is everything. The first thing to consider when performing your tree triage is the location of the tree. Regardless of tree age, size, species, or health, the trees that should always merit our immediate attention are those in locations where they could pose a danger to life or property if a limb were to fall off or if the tree were to topple altogether. Trees within striking distance of homes, power lines, and important structures like chicken coops and pet houses should always be the first inspected before the storm comes and after it passes. If a tree knocks down a power line or hits a home, call for help. Never attempt to work around a live cable (one that still carries electricity) without the proper training and equipment.
The second thing to consider as you perform your tree triage is health of the tree. Trees weakened by disease or age are more likely to succumb to strong winds or topple after standing water weakens or kills roots. Inspect your trees for symptoms of stress and disease such as branches that no longer produce leaves. Depending on the species of tree, a few may not be much cause for concern, but if there are several branches on a tree that no longer produce new leaves or needles, the tree is likely not in great health. Another symptom of stress or disease is a visible canker, or large wound, on the trunk of the tree. Trees in good health will typically grow new tissue over an injury sustained by pruning, animal feeding, or a previous storm. Cankers that appear to be getting larger over a few years, rather than smaller, are often a cause for concern.
There are even some obvious signs of disease such as conk or shelf mushrooms that grow directly from the wood of the tree. While these organisms are important for nutrient cycling in natural ecosystems, they often indicate that a tree is approaching the end of its life. The shelf mushroom is only the sexual structure of the fungus, there to produce spores and reach new trees. While removing the mushroom may slow the spread of the fungus to other trees nearby, the majority of the “body” of the fungus will still exist within the tree, weakening it by breaking down woody tissue over time.
Trees, like other living things, do not live indefinitely and become more vulnerable to illness and stress as they age. Just like people need to take care of themselves to ensure they live a long, healthy life, so too must trees be cared for over the course of their lives to ensure they have the best possible outcome. Regular fertilization and pruning are essential to not only ensure that a tree grows robustly, but also that it does not become lopsided or heavy on one side as it ages. Even healthy trees can fall if they are never pruned and have a poor center of gravity! Pruning should be performed frequently to promote new growth, discourage lopsidedness, and allow increased airflow through the canopy. This will have the double benefit of decreasing disease pressure that often accompanies high canopy humidity and prolonged leaf wetness. Though it depends on the species of tree, most here in New England perform best when pruned while they are dormant in winter. Remember to not remove more than 1/3 of the tree’s branches when pruning, if possible!
There are other factors to consider when determining if a tree should come down that we don’t have space to discuss at length here, such as the species of tree, whether the tree is used for other purposes (such as part of a living fence), whether the tree has historic or personal significance, or what removal of the tree may mean for other plants nearby that depend on its shade. And, of course, nobody should consider tree removal without considering cost and time. If cost is a concern, remember to do your triage and prioritize the management of trees that could potentially damage your home, property, or power lines if they were to fall. These considerations and others are worth discussing with an arborist as they survey your property!
For questions about planting and pruning trees or other gardening topics, feel free to contact us, toll-free, at the UConn Home & Garden Education Center at (877) 486-6271, visit our website at www.homegarden.cahnr.uconn.edu or contact your local Cooperative Extension Center.
Tying Climbing Roses
By Marie Woodward, UConn Home & Garden Education Center
Climbing and rambling roses are a beautiful addition to any garden, adding height and depth to your outdoor space. These types of roses require proper training and tying to ensure that they grow in the desired direction, produce the most blooms and don’t become tangled or unruly. Follow this guide on how to tie climbing and rambling roses to get the best results.
For materials, one would need some twine or soft plant ties, a sharp pair of pruning shears, sturdy long-sleeved, thorn resistant garden gloves. Also, some wire and tools to secure to a trellis, fence or other structure may be necessary.
Climbing roses have two types of canes. Main canes are stems that originate from the base of the rose giving it its structure and support. They are also referred to as leaders. Lateral canes originate from the main cane. It is the lateral canes that produce the flowers and add volume to the shrub. In general, main canes are not pruned unless they are diseased or dead.
Before you start attaching the plant to a trellis, make sure that your rose is properly pruned. Removing any dead or diseased canes will encourage healthy growth. Cut back any wild or overly long shoots to create a manageable framework for tying. Starting with this step will allow for more control as you move through the process of tying.
Supportive wiring, better known as strain wires, helps to promote flowering. They hold the main canes at a 45–90-degree angle. These angles encourage lateral canes to flush and produce more abundant flowers.
If you're training your roses against a wall or fence, attach the horizontal strain wires to the structure, spacing them about 12-18 inches apart vertically and 5 feet apart horizontally.
If you have a vinyl fence you can use vinyl safe hooks and secure the wire with a turnbuckle vertically, spacing them about two feet apart to avoid drilling holes in the vinyl material.
Using twine or soft plant ties, attach the rose canes to the support structure at regular intervals, starting about 1.5 feet from the ground. Tie them securely but not too tightly You want to allow room for the canes to grow and expand. Avoid fishing lines or other rigid materials. Using the wrong ties or tying too tightly could lead to cane injury.
As the roses push new growth, continue to tie the new main canes to the support structure. Continue to guide them in the desired direction, with those 45–90-degree angles as a guide.
Regularly check your roses and adjust the ties as needed. Ensure that they remain secure but not too tight. Prune any wild or unruly shoots and remove any dead or diseased wood to keep your roses healthy and under control.
By following these steps and regularly maintaining your climbing rose, you’ll create a stunning vertical display that adds beauty and depth to your garden. While this guide provides good tips on for starting and maintaining younger climbing roses, older roses that have been neglected may need restorative measures. If you need more information on climbing roses or any other gardening questions, feel free to contact us, toll-free, at the UConn Home & Garden Education Center at (877) 486-6271, visit our website at www.homegarden.cahnr.uconn.edu
It’s Spring! Time to Feed the Plants!
By Dawn Pettinelli, UConn Home & Garden Education Center
Plants need nutrients to grow and develop just like we need vitamins and minerals. They get most of their nutrients dissolved in the water they take up with their roots. When we add fertilizer to the soil around our garden plants, we are adding vital plant nutrients.
Native Connecticut soils are typically low in pH and low in nutrients. Our native plants have adapted to our native soils but most of our garden plants are not from around here. Zinnias and tomatoes are from South America, bluegrass lawns and lilacs hail from Europe and rhododendrons from Asia. Our native soils may not supply the nutrients they need so it is up to us to do so.
Of course, the best way to know which nutrients and how much to add is with a soil test. April is a very busy month at the UConn Soil Nutrient Analysis Lab (www.soiltesting.cahnr.uconn.edu) but there is still time to get your soil tested before planting.
Without soil test recommendations, always follow the directions on the fertilizer package. Applying too much can injure your plants plus excessive nitrogen and phosphorus can wind up in our waterways. Before fertilizing, calculate out the square footage of your garden or lawn. You don’t need to measure exactly; you can measure a pace and then walk down the length and across the width of your gardens to get a rough estimate of area. For odd-shaped beds or lawns, break them down into more square, oval or rectangular areas and add them up.
All fertilizers come with 3 numbers on the package denoting the percent, on a dry weight basis, of nitrogen, phosphorus and potassium. Nitogen promotes green, leafy growth, phosphorus encourages fruits and roots, and potassium is for all round health and tolerance to stresses like drought, cold and disease. So, fertilizers with a higher nitrogen number would be most appropriate for turf grasses, trees and shrubs, while ones higher in phosphorus are generally used in vegetable and flower gardens.
Whether you select a synthetic or natural organic fertilizer is a matter of personal choice. Both are beneficial to plants. For annual plantings, whether vegetable or flowers, it would be ideal to mix the fertilizer into the top 6 inches of soil. That’s where most of the roots will be so it makes sense that the nutrients they need are there too. Put down the fertilizer, as well as any limestone or other amendments shortly before planting. Long season annuals, like tomatoes, pumpkins and marigolds would appreciate a second application of fertilizer, referred to as side dressing, about 2 months after the first one.
As you are cleaning up your perennial beds and see the new shoots popping through the soil, add some fertilizer around plants and carefully scratch it in. Do the same for bulbs. It is harder to fertilize if the beds are heavily mulched. Not much fertilizer spread on top of mulch will make it to the plant roots. Rake or pull away the mulch, sprinkle some fertilizer directly to the soil around your plants and replace the mulch.
For trees and shrubs, fertilizer should be spread under the whole canopy as a healthy root system will grow at least as wide as the branches and perhaps even more so. Do your best to remove the mulch before fertilizing. Typically trees and shrubs are fertilized once a year in the spring. Once they have reached their mature size, often the fertilizer is cut down to half rate as woody plants can recycle many of the nutrients they need.
Lawns can be fertilized now but pay attention to the moisture level of the soil. With all the rain that we have been experiencing, the soil is pretty soggy in spots. Stay off wet soils as they will become compacted. Most lawns do well with just a spring and fall application of fertilizer. If the clippings are left down, they supply nutrients plus add organic matter to the soil. Be sure to set your spreader on the proper setting.
If you have questions about fertilizing or if you have any other gardening questions, contact the UConn Home & Garden Education at (877) 486-6271 or www.homegarden.cahnr,uconn.edu or your local Cooperative Extension Center.
The Do’s and Don’ts of Early Spring Gardening
By Heather Zidack, UConn Home & Garden Education Center
There’s a well-known scene in the movie “Braveheart” where Mel Gibson’s character, commands his men to “Hold!” as the enemy is rushing upon them. It’s a scene that I often reference as an analogy for this part of the year. Daylight savings time has changed our clocks, the sunshine is warm, temperatures are reaching the “light jacket” level of comfortable, and we all feel spring rushing towards us with the promise of seedlings, flower buds, and fresh green leaves. With this, there are certainly plenty of chores that we can do right now to prepare, but there are others that we really should be waiting for a few weeks longer.
Houseplants may enjoy a short afternoon in the outdoor sunlight on these warmer days but resist the urge to put them outside full time until night temperatures consistently reach 50 degrees Fahrenheit. The occasional day trip is an effective way to help them transition from the protection of your indoor environment to full sun outdoors. More importantly, consider giving your houseplants a good spring cleaning. Repot or divide root bound plants, remove the winter dust from leaves with a damp rag, and trim out any dead or unsightly growth. Now they’re ready for their spring debut!
Fertilizing is another task that many gardeners feel may be a chore to check off their lists early. This is a project that should wait a little bit longer. Often, fertilizer will push new growth in your plants. Pushing them too early can leave tender leaves and buds at risk of exposure to frost and freezing temperatures, actively slowing or stunting growth that you intended to give a boost to. In the same vein, grub control, pre-emergent, and many other synthetic materials used in the landscape require specific soil temperatures to be effective and it’s still just too cold. Always read the label of any garden product to learn the best timing of any application. At this point in the year, consider doing a soil test. If you haven’t done so before, it's great to have a baseline for planting and caring for your garden. If you’ve done it a few years ago – check it again! Things change and you may be surprised by what nutrients you need (or don’t) since you last checked in.
It may still be a little early for mulch as well. Adding fresh mulch too early in the season can trap moisture and slow the soil from warming up to optimum growing temperature. Take this time to pull out grass and weeds that may have taken root in mulched beds and put this time into your hardscape. Look for tripping hazards to address like cracked, sinking, or heaved pavers. Check structures like pergolas, sheds, and even raised beds for rotting boards, warping, or structural damage. Repair as needed. Building new garden spaces is always an option! Create your punch list of projects that will need fresh paint or sealant. If the weather is going to be warm and sunny – consider power washing hardscapes and structures now.
Late winter/early spring is a fantastic time for pruning trees and shrubs in the landscape. It’s ideal because there is great visibility, and the cooler temperatures prevent disease and insects from taking advantage of fresh wounds. You want to make sure you’re pruning correctly, for the species and purpose of the trees and shrubs in your landscape – so do your homework! As a rule of thumb, roses, hydrangeas, and some hardy perennials tend to appreciate a later pruning and can vary between types within the species, so stay aware of what you have on your property to ensure success!
“But when do I get to play in the dirt?” That's next! For our outside plants, think about dividing perennials. Divisions at this point in the year make the plants much easier to handle for the gardener. Moving your plants now gives them a chance to “wake up in place” this spring. You will reduce concerns with transplant shock when you move plants ahead of their spring flush and our summer heat.
Indoors, stepping your seedlings up into larger containers gives them a little more breathing room as we wait for the season to start. Only transplant seeds when they’ve started to show 2-3 sets of true leaves and keep in mind that different species can have different needs. If you excitedly started your tomatoes too early, and now notice leggy stems, try transplanting them in plastic cups and burying them all the way up to their first couple sets of true leaves. They will put out even more roots along that covered stem and be even better prepared when you put them in the garden this season!
There are still plenty of projects that can be done while we wait for spring to come! If you have questions on spring garden projects or any other gardening topic, feel free to contact us, toll-free at the UConn Home & Garden Education Center at (877) 486-6247, visit our website at www.homegarden.cahnr.uconn.edu or contact your local Cooperative Extension Center.
Prune Now for Beautiful Summer Trees
Prune Now for Beautiful Summer Trees
By Marie Woodward, UConn Home & Garden Education Center
Winter is a great time for gardeners to plan for their next growing season. Many think that planning can only be done inside. Not so. Now is an ideal time to prune deciduous landscape trees. The absence of leaves gives a clear view of the canopy above and allows for a clear assessment of a tree’s structure and any problems that may be present. In addition, there are no pests present in winter, and disease spread will be slowed by the cold weather. But before heading outside with those loppers and pruning saws, there are a few important things to know and consider.
It's important to understand the tree’s anatomy. A typical deciduous landscape tree will consist of three main parts: the leader, the scaffolding branches and the lateral branches. The leader is the dominant vertical branch of the tree. This is easily spotted as the straight, most upward growth from the trunk. The leader is the tree’s most important branch, crucial for the tree’ structure, photosynthesis, and even distribution of nutrients. Scaffolding branches emerge from the trunk and the leader to make up the canopy of the tree. Secondary branches that grow from the scaffold branches are called lateral branches. Once you understand the basic structure of the tree, it’s much easier to successfully prune it.
Photo from Virginia Cooperative ExtensionFirst, assess the tree. What species of tree is it? That will reveal its natural structure, something your pruning should ideally strive to support. Note though, that proximity to buildings or human activity nearby is likely to influence your pruning strategy (keeping scaffolding branches clear of buildings, for example, or making sure people can walk under the lowest branch?)
Locate the leader of the tree and look for problem branches. Dead, diseased, damaged, or crossing branches should be pruned first. When pruning dead or diseased branches, make cuts into healthy wood, well below the affected area. It’s also a good idea to disinfect tools between cuts to help prevent the spread of disease. (A 10% solution of bleach to water works well.)
After the tree’s diseased, damaged, or crossing branches are pruned, look for lateral branches that are trying to compete vertically with the leader. They can draw energy away from the leader and sap the tree’s vigor. Usually, there is no need to remove all of a competing branch. Just pruning the vertical portion back to the scaffold branch should be sufficient. This will slow the competitor branch’s rate of growth, allowing the leader to dominate.
When pruning a scaffold branch, it is important to cut outside the branch collar. That is the swollen area at the base of the branch, where it joins the trunk. Make the cut outside the branch collar at a 45-to-60-degree angle to the trunk and leave it alone to heal naturally. There is no need to coat or cover cuts. Doing so could prevent the wound from healing and might seal in pathogens adversely affecting the health of the tree.
According to Pete Smith, forester and arborist from the Arbor Day Foundation, there are five main factors to consider when pruning trees:
- After pruning, two-thirds of the height of the tree should still have branches and leaves to keep growing in a healthy manner.
- Do not remove more than one third of the total branches in one year.
- Branches attached to the trunk should not be more than one half of the diameter of the main trunk.
- Every pruning cut should be no more than one inch in diameter
- There should be a total of five cuts in a year.
Of course, when pruning a long-neglected tree, it may take a few seasons to be able to apply all five rules, but ultimately, your trees will be healthier and more beautiful if you follow these guidelines.
For questions about pruning or if you have any other gardening questions, contact the UConn Home & Garden Education at (877) 486-6271 or http://www.homegarden.cahnr.uconn.edu/ or your local Cooperative Extension Center.