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Helping Plants During the September-October Drought

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By Pamm Cooper, UConn Home & Garden Education Center

A sloped yard showing signs of drought stress.
Drought stress on a sloped lawn. Photo by Pamm Cooper

Here at the UConn Home and Garden Center we have been getting questions about lawn and garden issues that have been particularly widespread in the state. Whether in the landscape or the garden, there is always something going on, good or bad, and keeping up with pests or cultural issues can be challenging. Because of the extended late season drought conditions this year, plants may be showing signs of stress. There are some basic things homeowners can do to help plants go into winter as healthy as possible.

Plants in temperate climates, like we have in New England, are normally manufacturing food to enable carbohydrate storage for new growth that will occur next spring. To do this, plants need both sunlight and water, and our extended drought conditions have limited most plants to enter survival mode, and carb storage is a second priority. The best way to help your plants is to water deeply any that still have green leaves. People with wells may need to determine if this is a priority for them. We can hope for a warm winter or insulating snow cover to help any plants with shallow roots survive until warm weather returns.

Drought stress on dogwood leaves
Drought stress on dogwood leaves. Photo by John Ruter

One sign of drought stress in woody broadleaf plants is leaf edges that curl upward. This is a good clue as to the beginning of water stress. Make sure to water these plants deeply, to ensure roots will be able to pick up the water. Usually the next day, leaves will start to uncurl if adequate water is applied. If drought stress continues, leaves may turn brown at the edges and early leaf drop may occur.

Evergreens, even established ones, can benefit from regular watering as long as the soil is not frozen and drought conditions remain. Evergreen foliage, whether needles or leaves, photosynthesize all year, and it is important that soil is not dry. Normally, we have snow that melts on and off, and if soils are not frozen, roots will be able to take up water and photosynthesis can still take place.

Perennials of certain species may be doing fine in this drought. Yarrows, some ox-eyed daisy cultivars, obedient plants, goldenrods, mountain mints and Agastache may be showing no signs of stress. Still, if any have green leaves at this point, consider watering them if dry and warm conditions continue.

This weekend I planted a small shrub, and I had to dig about fourteen inches down to accommodate the root mass. I have to say that I was surprised that the soil, not particularly one that dries out often, was powdery to the bottom of the hole. If you are planting anything now, make sure to water the soil thoroughly as you fill in the area around the roots, then water again when done. This is especially needed for small trees and shrubs but do the same for perennials.

Next year, woody plants that were impacted by drought this year may be more susceptible to certain diseases like verticillium wilt, Nectria canker and evergreens to Rhizosphaera needlecast. Be vigilant and scout for any signs or symptoms of these diseases.

Lawns that did not receive any rainfall or supplemental watering during the past two months may be dormant and crunchy at this time. It may not be clear if the grass will recover when temperatures cool and adequate water is applied. Some grass species may be dead, but it may not be clear until next spring when they fail to green up. There still may be time to apply supplemental irrigation, and with warm temperatures, grass may or may not green up, but at least the crowns may be kept alive to generate new leaves next spring. If any lawn areas were seeded in late summer, water new grass as needed. If it is wilting, water it for sure.

Be alert to what is happening in your own backyard, for the sooner you discover any problems the better. Contact us at the University of Connecticut Home and Garden Education Center for advice on lawns, landscapes, and other gardening subjects. Here's hoping for some needed rainfall and cooler temperatures to help our plants recover from the trying drought of 2024.

Penn State Extension has a good article on long-term effects of drought stress- https://extension.psu.edu/the-long-term-impact-of-drought-on-trees-and-shrubs

If you have questions about caring for plants during a drought, or if you have 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 or contact your local Cooperative Extension center.

Calling the Cut – Tree Triage, Care, and Removal

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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!

Tree with branches missing on one side.
Storm damage caused this tree to lose branches on one side. This lopsidedness increases risk to property below. Photo by H. Zidack

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.

How to Identify and Treat Salt Damage on Plants

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How to Identify and Treat Salt Damage on Plants
Laurel Humphrey, UConn Home & Garden Education Center

From freezing temperatures to blistering winds, the harsh winter elements can pose a challenge for people and plants alike. One common issue many gardeners face during the wintertime is salt damage on plants. While deicing road salts help to ease our troubles by keeping roads, driveways, and sidewalks clear, they only intensify winter damage on the ecosystems and plants nearby. As a country, the U.S. is estimated to apply about 20 million tons of salt per year for public safety on roadways. The most common form of deicing salt used to keep ice from forming on the roads is sodium chloride, or rock salt, which can be very damaging to vegetation. Deicing salts contribute to the damage and dieback of landscape plants each year, however there are steps one can take to identify salt injury and minimize its effects.

What are Symptoms of Salt Damage in Plants?

When deicing salts inevitably wash off the roads, they threaten plants both directly through contact with the foliage, as well as indirectly by changing the soil chemistry. In what is known as “spray zone” injury, salt water collects on plant foliage and enters the plant cells directly. This type of salt injury results in discoloration beginning at the margins of the plant and may eventually lead to premature leaf or needle drop. Salt spray can also dry out bud scales, exposing the developing leaves and flower buds to reduce growth later in the spring. Spray zone injury often produces a distinct pattern of damage, where symptoms are restricted to foliage facing the roadside and increase in severity as plants are found closer to the road.

Another way plants are affected by road salts is when runoff salt water dissolves in the soil and is taken up by plant roots. Within the soil, sodium chloride breaks down into ions that compete with the other nutrients plants need to survive. As a result, plants take in more of the harmful sodium salts and less of the beneficial nutrients they require. Plants tolerate small amounts of salt naturally, but toxic concentrations can result in symptoms of wilting, scorch, and burn. Overall, deicing salt exposure causes symptoms similar to drought and root damage in plants, such as tip browning, bud death, stem dieback, stunted growth, marginal burn and discoloration, and even tree death. These effects may vary depending on the plant species and degree of exposure, with salt applications in late winter thought to be most damaging to plants and less likely to be leached away from roots.

A row of bushes exhibiting salt damage
Deicing salt exposure can result in the damage and discoloration of plant foliage along roadsides. Photo courtesy of Joseph LaForest, UGA, Bugwood.org.

How can Road Salt Injuries be Managed?

In order to minimize the harmful effects of road salts and be sure your plants will make it to see a healthy spring, there are some steps you can take to reduce salt injury. One obvious option is to limit the use of road salts when possible, especially near lawns and landscapes. This can be done by mixing salt with other materials such as sand or sawdust to help maintain road traction, as well as choosing other salt options like calcium chloride that are less harmful to plants, although more expensive. Gardeners can also protect their plants from salt damage by covering them with materials like wood or burlap, and being careful to plant salt tolerant species near roads and sidewalks. Trees such as hedge maple, paper birch, and Northern red oak are more tolerant to salt exposure than sensitive species including red maple, boxwood, and Eastern white pine.

While it is not always possible to prevent salt damage from becoming an issue during the winter months, other management strategies can be used to treat salt injury. If you do identify exposure to salt damage in your landscape, be sure to wash salts off plant foliage as soon as possible. Prevent snow piles, sand, and runoff from building up near sensitive plants, and maintain healthy soil salinity levels through the addition of organic matter. The most effective way to minimize salt damage is by leaching salts away from the plant roots. Apply fresh water often to flush salts down through the soil when the ground is not frozen, and plant roots should be less vulnerable to the toxic effects of road salts.

Laurel Humphrey is a student employee working with the Plant Diagnostic Lab and Home & Garden Education Center. For questions on road salt 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.