Weather Events

Spring Showers Bring Flooded Gardens

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By Amelia Martin, UConn Plant Science Graduate Student 

You may have noticed the heavy rains and chilly temperatures last week’s nor ’easter brought to Connecticut. Maybe you were one of many who checked their back window to see their gardens had flooded and their plants are looking worse for the wear. If this sounds familiar and you are curious what garden flooding means for your plants and want to know how to protect them- you found the right article! 

A flooded garden is not a unique problem, especially during periods of heavy rainfall, but there are some factors that may contribute to the severity of flooding. Having minimal or poor drainage can amplify the problem, especially if planting in garden boxes with closed bottoms. Soil compaction can contribute to flooding if you are planting directly in the ground. Compacted soil can happen if there has been too much tillage, if wheels or machinery have been over the area, or even from excess foot traffic. Lastly, the layout and landscaping of a yard can contribute to flooding as well. If you placed your garden at the bottom of a hill or there are minimal drainage angles surrounding your garden, water may be pooling up faster than it can drain.  

To prevent flooding, check your gutters and make sure they are free from debris and directed to a drain or storm barrel. Put down gravel and mulch to help prevent surface flooding. Avoid cutting your grass too short to maintain strong roots which help to absorb water. Maintain healthy soil to allow for the best water absorption. Dig out a shallow drainage channel if you have the space for it. Consider switching to raised beds with drainage rather than in-ground gardens in easily flooded areas. Try adding native plants to your garden. Native plants have deep roots which helps them absorb excess water and prevent runoff. While handling these issues would be preventative measures, let’s talk about what to do if your garden has already flooded.  

Assess the drainage situation and take note of where the water is pooling the most. If flooding is unusual in your garden- there may be something blocking the normal drainage route, which may be a quick fix. If not, knowing where water is likely to pool may help in future garden planning, or help you determine where to make improvements.  

Stay off your garden beds.  If you step on your soil while it is saturated, it will compact it, ruining the soil’s tilth. Instead, if you need to access your garden beds consider putting a wooden board down to walk on to distribute your weight better. 

Re-fertilize your plants. Heavy rain can wash away nutrients out of the soil through a process called leaching. Check the forecast to make sure no more extreme weather is immediately approaching before fertilizing- or you may have to do it again. 

Add supports to your plants. The wind and rain may have led to plants falling over. Add in some additional supports to get them upright again and give them a better chance for the next time heavy rain comes.  

While having a flooded garden may be a bummer, there are some gardening activities that are actually easier to do in saturated soil! Once the rain stops and the ground is still wet, use this time to weed. The soft ground will make weeds especially easy to pull up- just try not to step on the garden beds. After a rain or a flood, re-mulching is always a good idea. The rain might wash away some previously placed mulch, use this as an opportunity to locate any spots barren of mulch and in need of a re-fill. After a couple days when the soil is soft but not sodden, the ground will be the perfect consistency to dig and put stakes.  

Lastly, check for any young plants that didn’t survive the water or any seeds that haven’t come up. Take this as an opportunity to plant new seeds, as seeds do better in already moist soil where they have less chance of being displaced when watered.  

At the end of the day, while having a flooded garden may not be the best for your plants, it is not the end of the world. There are a handful of preventative measures that can be taken ranging from backyard renovations to quick fixes- it is about finding what works best for you and your garden.  

The UConn Home & Garden Education Center supports UConn Extension’s mission by providing answers you can trust with research-based information and resources. For gardening questions, contact us toll-free at (877) 486-6271, visit our website at homegarden.cahnr.uconn.edu, or reach out to your local UConn Extension center at cahnr.uconn.edu/extension/locations. 

This article was published in the Hartford Courant May 31, 2025

Spring Landscape and Garden Issues in 2025

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By Pamm Cooper, UConn Home & Garden Education Center This spring has been a dramatic one as ornamental trees and shrubs are putting on quite a colorful floral display. Many deciduous ornamentals including redbuds, forsythia, crabapples, fruit trees, quince azaleas and many others were not adversely affected by last summer’s drought and the cold, windy winter and frozen soils that followed. A lesser noticed but significant drama is the negative effect these same environmental conditions had on ornamental and native evergreens. 

Rhododendrons and ‘Green Giant’ arborvitae seemed to suffer the most damage followed by cherry laurels and hollies. Last year’s drought conditions that extended into late fall combined with very windy winter conditions and frozen soils were tough for some evergreens. Winter desiccation injury on broadleaved and needled evergreens causes foliage browning when plants cannot take up the water needed to keep foliage healthy. Damage to many rhododendrons and some azaleas could be seen during the winter and is still evident this spring. Buds may provide new leaves by June if branches are still alive.  

In contrast, 'Green Giant’ arborvitaes suddenly showed symptoms after warm weather began this spring. This was evident especially in trees on windy sites. Needles are brown or off color and time will tell if they are able to recover. If branch tips are flexible and show new buds, growth may resume. Prune any dead branches that show no signs of recovery. 

Large tent like structures with little caterpillars inside them in the crotch of a tree branch.
Eastern Tent Caterpillars in a Black Cherry Tree. Photo by Pamm Cooper

Eastern tent caterpillars have hatched from overwintering egg masses on native black cherries. Silken nests are evident located in crotches of these trees. Caterpillars feed outside the tents at night and hide in them during the day. There is only one generation, and feeding is generally finished by late June. Trees have time to leaf out again to remain healthy during the growing season. Birds like cuckoos and vireos will rip tents apart to feed on the caterpillars. 

If you have Oriental lilies, be alert for the lily leaf beetle. This bright red insect can severely defoliate these lilies. Adults overwinter in soil close to the plants they were feeding on the previous season. They appear as soon as lilies begin new growth above the ground. Leaf undersides should be checked for eggs and larvae and crushed when found. Leaves can be treated if needed with a product that larvae will ingest as they feed on the treated leaves. Never spray flowers with any insect control product and always follow directions as written on the product label. 

Snowball aphid feeding damage is noticeable on the new leaves of European cranberry bush and snowball viburnums. As the aphids feed on the new leaves and twigs, leaves curl and twigs twist in response to aphid feeding on the sap. Aphids can be found by uncurling the leaves. Treatment is difficult as they are not out in the open where contact control products can reach them. Feeding should end within two months of egg hatch. These aphids overwinter as eggs laid on the branches of host viburnums. 

Viburnum leaf beetles, Pyrrhalta viburni, are another significant pest of ornamental and native viburnums. They’re active soon after viburnums leaf out. Damage will be seen as larval populations grow and they skeletonize leaves. Some viburnums may suffer complete defoliation. This pest prefers arrowwood, European cranberry bush or American cranberry bush viburnums. Try switching to resistant varieties such as V. plicatum and Korean spicebush viburnum V. calesii if leaf beetles are a chronic pest. 

If anyone has small St John’s wort shrubs or certain weigela cultivars that seem to be dead, wait and see if new growth resumes as it gets warmer and sunnier. The smaller St. Johns’ wort shrubs die back in fall, leaving brown stems with withered fruit. Prune these back almost to the ground as basal growth appears. Some weigela cultivars are just slowly getting started, while others are already full of leaves. Do not give up these plants but wait and see what happens in May. 

As always, our UConn Home and Garden Education Center office staff welcomes any questions gardeners may have concerning landscape and garden plants problems. Across the New England region, people are having much the same problems as we are having in Connecticut from the winter weather, but we can hope that plant recovery be swift and complete. Enjoy the growing season and stay alert- scout for pests and other problems before they get out of hand.  

The UConn Home & Garden Education Center supports UConn Extension’s mission by providing answers you can trust with research-based information and resources. For gardening questions, contact us toll-free at (877) 486-6271, visit our website at homegarden.cahnr.uconn.edu, or reach out to your local UConn Extension center at cahnr.uconn.edu/extension/locations. 

 

 

This article was published in the Hartford Courant May 10, 2025

Rocky Start for Rhododendron’s This Spring

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By Heather Zidack, UConn Home & Garden Education Center

Two Rhododendron shrubs. Shrub in the foreground showing leaf curl while shrub behind it looks healthy and is not displaying any signs of stress.
Rhododendrons are showing a varying degree of stress responses to winter conditions in the landscape. Photo by Heather Zidack

Rhododendrons are looking rough this spring. You’ve probably seen it in your yard or in your neighborhood. The UConn Home & Garden Education Center has been seeing an increase in the number of calls regarding injury or damage to rhododendrons.  In most cases, we are finding these reports to be winter injury. This is an environmental type of damage, caused by a perfect storm of conditions that we have seen throughout the state. So, let’s take a closer look into why this is happening.

Plants lose water through their leaves. During active growth, that water is constantly replenished from the roots. When the temperatures drop and the ground freezes in the winter, available water becomes limited. Plants have adapted to this in many ways. Dormancy is triggered by multiple factors, but water conservation is certainly one of those. Deciduous trees shed their leaves completely. Evergreens have developed various leaf adaptations to help with survival, too.

As broadleaf evergreens, rhododendrons have developed a waxy coat on their leaves to help prevent water loss. They also have a physiological mechanism to help defend themselves further. Just as you’d clasp your hands together on a cold winter day to shield them from the elements, rhododendron leaves curl themselves into cigar-shaped cylinders. The leading theory is that this happens to protect the leaves from further water loss. This natural defense mechanism has grabbed our attention this spring, since our weather patterns have lent a hand in amplifying a natural phenomenon.

At the end of last summer, CT started to see a moderate drought in much of the state. These conditions have persisted through this spring. Water availability was limited as plants went into the winter and remained limited throughout the season. Add in frozen soil and harsh winter winds and the environmental stress increased even more. When water is unavailable to the roots – through either freezing or drought conditions, plants lose their ability to return water to the living tissues. This drying out, referred to as desiccation, leads to winter injury or winter kill depending on the severity of damage. While we are finally seeing rain, these plants need time to recover and may not be ready to unfurl just yet.

Many have noted that some plants are faring better than others even within the same bed. This is also normal to some extent. It can be easy to forget that plants are living things in our landscapes. There is going to be variance in their ability to withstand environmental pressures and their recovery rates.

If you are seeing this in your rhododendrons, be patient this spring and monitor over the next month or so. With an increase of rain in the forecast, the extra hydration should help plants recover - or at least push out new growth. These shrubs will shed any leaves that are damaged beyond repair on their own. Do not prune or fertilize shrubs until the end of May to avoid further injury.  If we go a week without rain, consider watering your shrubs to help speed up recovery – but only water if the soil feels dry to the touch! If by mid-late May you are seeing absolutely no improvement, we start to consider other factors that may contribute to the plant’s health. For now, they just need a little more time.

The UConn Home & Garden Education Center supports UConn Extension’s mission by providing answers you can trust with research-based information and resources. For gardening questions, contact us toll-free at (877) 486-6271, visit our website at homegarden.cahnr.uconn.edu, or reach out to your local UConn Extension center at cahnr.uconn.edu/extension/locations.

This article was published in the Hartford Courant Apr. 12 2025

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.