By Dawn Pettinelli, UConn Home & Garden Education Center
Photo by Dawn Pettinelli
For many, the sight of a lush green lawn brings about the desire to cast off one’s shoes and stroll through the sun-warmed grass feeling the soft verdant carpet below. Lawns, or at least grassy areas, are a ubiquitous part of almost every home outside city limits. While admittedly that perfect lawn is a source of curb appeal and homeowner pride, in recent years considerable attention has been given to the ecological and environmental costs of maintaining turf that is the envy of the neighborhood.
Managed turf grass areas, including golf courses and park areas cover about 8 percent (400 square miles) of the land area in Connecticut. That perfect lawn typically requires supplemental irrigation, fertilizer, regular mowing and often pesticide applications. Water could be better used for drinking, other domestic uses and just left in natural systems. Excess nutrients as well as pesticides can be found in ground and surface waters causing both human health as well as ecosystem problems. While some are turning to electric mowers and blowers, gas-powered equipment dependent more on fossil fuels, are most prevalent (at least in my neighborhood) contributing to climate change.
So what is a residential lawn owner to do? The authors of Redesigning the American Lawn were among the first to coin the term “freedom lawn.” So, what is a freedom lawn? Basically, anything that is green is allowed to grow. That would include dandelions, self-heal, violets, bluets, buttercups, clover and wild strawberries to list a few of those so-called “low growing broad-leaved plants”. By my definition, weeds are plants growing in the wrong place, so the plants are weeds no longer when accepted as part of the lawn.
One of the greatest reasons for encouraging a variety of plants to inhabit turf areas is that the world is facing a critical loss of biodiversity. There are significant declines in beneficial insect, native plant and bird populations, along with other living organisms. While that lush green lawn offers aesthetic pleasure to some, it does little to provide habitat or food for creatures other than problematic ones like grubs or chinch bugs.
A mixed grass- herbaceous plant lawn will contain flowering plants for pollinators and other beneficials. Various plant species have varying root systems. Some have deep taproots that break up compacted soil and bring up minerals. Others have more fibrous root systems that are continuously turning over added organic matter to the soil. A variety of plants along with their root exudates and associated microbes can help aggregate the soil, improving air and water passage. Porosity plus water holding capacity can be increased as well as lessening the potential for topsoil erosion. A healthy plant community usually portends a healthy soil.
Leaning into a freedom or pollinator lawn does not mean digging up one’s entire lawn and reseeding it although that is one option. Two seed mixes that I have seen advertised are Flawn and Fleur de Lawn. Both contain a mixture of fescues, microclover and the latter, some other flowering species. Probably greatest success with these seed mixes would be achieved starting with bare soil.
One can start encouraging biodiversity and pollinator plants by discontinuing the use of herbicides and allowing some flowering plants to move in. Often, they can be mowed before they set seed. When reseeding bare spots, use more drought tolerant fescues or native grasses like little bluestem to reduce the need for irrigation, once established. Higher mowing heights up to 3 or 4 inches will encourage deeper rooting of all plants making them more resilient during periods of drought.
Learn about the benefits of some of the low-growing broad-leaved plants that want to call your lawn home. Clovers add nitrogen to the soil reducing the amount of fertilizer necessary. Violets are host plants for the endangered regal fritillary. Dandelion greens are a great source of vitamins A and C. It is true that many of these plants are not native, but neither are the cool season turf grasses normally found in lawns.
In many yards, keeping part of it in lawn is essential for children’s play and sports activities, pet areas and entertaining. Take a tour of your yard and determine where a lawn makes sense and where it might be more appropriate for woody plants, ornamental beds or even a vegetable garden. Steep slopes or perpetually shaded areas may be best for groundcovers. Areas where water frequently collects after heavy rains might be more suitable for a rain garden.
However small, every effort to encourage biodiversity, provide for our beneficials and improve soil health is a step in the right direction. Rethinking your lawn areas might be a good place to start.
For information on lawns 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.
By Pamm Cooper, UConn Home & Garden Education CenterThis 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.
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.
“A garden is a grand teacher. It teaches patience and careful watchfulness; it teaches industry and thrift; above all, it teaches entire trust.”
— Gertrude Jekyll
Maximize your Garden Space this Season!
Gardening comes in all shapes and sizes, whether its a few pots on the patio, a large in-ground bed, or somewhere in between. We love the challenge of getting the most out of our gardens and finding new methods to increase efficiency and yield. There's many techniques out there - which one is best for you?
Click on each title to learn more and keep in mind that these are only a few of many techniques gardeners use to maximize their productions!
Intercropping
This practice focuses on growing two or more crops in close proximity to maximize the use of space in the garden. Plants need to be of similar culture in terms of watering and care needs in order to be successful. Often, timing of harvest can be a significant player in this system. Planting radishes in between broccoli, for example, ensures that the radish will be harvested before the broccoli needs additional space to produce its crown.
Companion Planting
While it may seem easy to use companion planting and intercropping interchangeably, they are two different practices. Companion planting focuses more on the relationships between plants and their environment. For example, some companion plants benefit others by deterring pests or fixing nitrogen into the soil. These complex relationships add benefit to your garden while also maximizing space.
Succession Planting
This method involves re-planting immediately after harvest to utilize the space for as long as possible. For example, planting escarole and lettuce once warm season vegetables have been harvested can help extend the gardening season. Alternatively, planting peas from seed every 2 weeks during the months of April & May ensures staggered harvest when compared to a single planting ready for harvest at the same time.
Square Foot Gardening
Looking to create an organized and efficient vegetable garden this growing season? Try using the square foot gardening method. In this technique, the growing area is divided into small sections, each one square foot in size. The result is an orderly garden grid with a different plant species in each square. Construction is simple and can be done with minimal materials.
Container Gardens
We are fortunate that the availability of container-friendly production plants has been increasing over the years! If your garden space is limited, seek out plants that are specifically intended for containers.
Drought Injury Continues
A hedge of Green Giant Arborvitae showing signs of winter damage. Note that the one on the far right appears to be unaffected, likely due to some sheltering from winter winds. Photo by Pamm Cooper, UConn Home & Garden Education Center
Connecticut's woody ornamentals have suffered from a unique challenge this past winter season: the lingering effects of a moderate drought during the preceding fall, along with cold temperatures and harsh winds. This combination of factors poses a threat to the health and vitality of trees and shrubs, exacerbating the typical stressors of winter in New England.
Many gardeners even reported a delayed response, noting that their evergreens looked okay throughout the winter and early spring. While drought-stressed plants are generally more susceptible to winter injury, this year's moderate fall drought has weakened many woody ornamentals, leaving them vulnerable to frost damage, branch dieback and pathogens, which become opportunistic when woody ornamentals are under stress.
Monitoring your trees and shrubs over the coming season will help you mitigate any further damage. Providing supplemental water when less than 1" of rain is forecasted for the week may also help plants out of this stressful time. Checking the soil before watering will help you avoid overwatering, which can cause its own host of issues.
Wild ginger, Asarum canadense, is a native plant that is a good choice as a shaded groundcover. Found naturally in woodlands in the eastern U.S., flowers are often overlooked as they are hidden near the ground below the leaves of this low-growing plant. Not considered edible, it is unrelated to the ginger used in cooking.
Shopping for native plants this spring? UConn has created a valuable resource that not only identifies CT Native plants, but helps you find the garden centers that carry them!
As we move into the summer the common plant clover starts to pop up everywhere throughout your lawn! However, instead of hand pulling or digging out the “weed”, should you actually keep it in your yard this summer? The answer is: yes! Clover is actually extremely beneficial to the environment in multiple different ways, and is also more drought tolerant, requires less fertilizer than grass, and attracts pollinators such as bees! This plant is a nitrogen fixing legume, which forms a symbiotic relationship with Rhizobia bacteria that start to form bumps that are able to extract the nitrogen from the atmosphere. When the nitrogen is extracted, the Rhizobia helps turn it into a usable form for the legume, and it “fixes” it within the plant. Clover is a great plant to keep in your lawn this summer!
By Zaira O’Leary, University of Connecticut Sustainable Plant and Soil Science Undergraduate
A seasoned gardener always keeps their eye to the sky at any time of year! Maps and the 30 day outlook from NOAA will help you stay prepared for any and all of your gardening chores! (Click image to see larger map.)
Gardening Resources & Pest Alerts
During the growing season, UConn Extension publishes a regular pest alert for both vegetable and fruit producers. Additionally, the New England Vegetable Management Guide offers a lot of information about specific vegetable crops.
While the target audience for these publications is usually commercial growers, home gardeners can learn a lot from these materials including identification and management of common pests in your veggie gardens!
If you ever need confirmation on an ID or have additional questions about what you read in these reports, please do not hesitate to reach out to us at the Home & Garden Education Center! We're happy to help your gardens thrive.
Supplement Your Garden Produce with CT Grown Products!
Photo by Peter Morenus/UConn Photo
Connecticut is rich in agricultural history, with many operational farms that have lots to offer local markets!
Supporting local CT Agriculture is a way that gardeners can supplement the fresh foods they grow in their garden, with seasonal offerings from year round operations.
Consider attending a local farmers market, joining Community Supported Agriculture (CSA's), or even stopping by your nearest farm stand to see what they have to offer!
In spring, some farms and farmers markets even offer plant starts for sale to be planted in your home garden.
This Memorial Day we also recognize ctveterangrown.org as a valuable resource for both veteran farmers and community members who wish to support Veteran-Owned or Operated Farms in CT.
Harden off tomato, eggplant and pepper transplants before planting out at end of month.
As night temperatures moderate into the 60's, move houseplants outdoors. Help them with the transition by putting them outside on warm days and bringing them in on when nights are too cold. Avoid putting them directly into full sun or windy locations.
Remove any tree wraps or guards you placed on young trunks for winter protection.
Remove spent blooms on tulips, daffodils and other spring flowering bulbs. The plant will focus its energy on growing new bulbs rather than producing seeds.
Use fresh potting soil in your containers as old soil has fewer nutrients and may contain harmful bacteria and fungi.
Mow your lawn any time the grass is 1½ times the normal height, for example, if you mow at a 3-inch height, don’t let the grass get longer than 4 to 5”.
Aphids and lace bugs will appear soon. Spray with water or use a low-toxicity insecticide to control them. Asian lady beetles are a beneficial insect that feed on aphids.
Put nets over ripening strawberries to protect them from birds and other wildlife.
Clear grass and weeds from root zone areas around tree trunks and remove any suckers growing from the base of the trees. Spread compost and top with 3 to 4” of bark mulch. Keep mulch an inch or two away from the trunks.
Disinfect all pots and containers before refilling them for the season.
By Marie Woodward, UConn Home & Garden Education Center
USDA Hardiness Zone Map for Connecticut, 2023
If you are wondering whether that shrub, flower, or tree that you saw in a magazine or catalog will grow well in your garden, using a hardiness zone map is your best bet to ensure success.
A hardiness zone map is a tool that divides a geographical area into distinct zones based on average annual minimum winter temperatures. These maps are used by gardeners and farmers around the world to determine which plants are most likely to thrive in a particular region. Each country has its own hardiness map that correlates to their climate. In the United States, the USDA publishes a hardiness zone map, which covers all fifty states and includes Puerto Rico, Guam, American Samoa, and the U.S. Virgin Islands. It uses climate data collected over many years from weather stations throughout a specific region. Then the data is analyzed to determine average minimum winter temperatures from different areas.
The concept of hardiness zones was first introduced in 1927 by Dr. Alfred Rehder. Rehder worked at Harvard's Arnold Arboretum as a botanical taxonomist. He wanted to address the challenges gardeners and growers faced in selecting plants suited to their local climate. Prior to Rehder’s map, there was no standardized system for categorizing plants based on their ability to survive winter temperatures. His hand-drawn map featured eight hardiness zones and was based on the lowest winter temperatures recorded in various regions across the country. Rehder aimed to provide a practical tool for gardeners and growers. His map made it easier for them to choose plants with the best chances of survival in their region, ultimately contributing to more successful gardens and agricultural endeavors. Rehder’s innovative approach recognized the importance of adapting agricultural practices to local climates. In the 1960s, the USDA adopted and adapted Rehder's concept, creating the first official USDA Plant Hardiness Zone Map.
Since its initial release, the USDA Plant Hardiness Zone Map has been updated several times to reflect changes in climate and the availability of more accurate data. The latest update of the USDA hardiness map was released in November 2023, jointly developed by the USDA's Agricultural Research Service (ARS) and Oregon State University's PRISM Climate Group. This update incorporates data from 1991 to 2020, covering a broader range of weather stations than previous versions. One of the key findings from this update is that the contiguous United States has become approximately 2.5 degrees Fahrenheit warmer on average compared to the previous map. As a result, around half of the country has shifted into the next warmer half zone, while the other half has remained unchanged. The updated map still consists of 13 zones, but now offers more detailed information on temperature ranges within each zone, including 10-degree zones and 5-degree half zones. Connecticut has two hardiness zones each of which is divided into half zones; (6a,6b); (7a,7b), to better reflect the temperatures in the state over the past few decades.
The importance of hardiness zones lies in their ability to help gardeners and farmers choose plants that will thrive in their specific region. By selecting plants appropriate for their zone, growers can reduce the risk of frost damage and increase their chances of a successful growing season. However, due to unexpected temperatures outside the average range, there is no guarantee that a plant won’t suffer but it does reduce the risk of plant damage. In addition to gardeners, researchers use hardiness zones to study the spread of insects and exotic weeds, while the USDA Risk Management Agency uses the map to help determine crop insurance rates for commercial growers.
While the USDA Plant Hardiness Zone Map is an invaluable tool, it is important to note that it is not the only factor gardeners and farmers should consider when selecting plants. Other factors, such as soil type, precipitation, and local microclimates, can also impact plant growth and survival. Gardeners should use the map as a starting point and supplement it with local knowledge and research to make the best plant selections for their specific needs.
The development of the USDA Plant Hardiness Zone Map is a testament to the importance of adapting agricultural practices to local climates. Since its inception nearly a century ago, the map has evolved to reflect changes in climate and incorporate more accurate data. Today, the map remains an essential resource for gardeners and researchers alike, helping them to better understand and navigate the complexities of plant growth in the diverse regions of the United States. Knowing a plant’s hardiness zone when selecting that shrub, tree or flower will help you grow the garden of your dreams.
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.
By Dawn Pettinelli, UConn Home & Garden Education Center
Photo by Dawn Pettinelli
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.
Photo by Dawn Pettinelli
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.
Beans like this Dragon Tongue variety can add interest to your vegetable garden! Photo by H. Zidack
Full of fiber, packed with protein, and great to grow, beans have been a staple in the diet of humans for thousands of years. Native edible beans can be found on every continent but Antarctica, although many of the beans we eat today are domesticated varieties that originated in South America, Europe, and Asia. Fabaceae, the bean family, is one of the largest families of plants in the world, with over 20,000 species described. As legumes, beans can convert nitrogen in the atmosphere into nitrogen useable by other plants, making them very useful to integrate into crop rotation for savvy home gardeners who want to save a little money on nitrogen fertilizer. In fact, excessive nitrogen fertilization of legumes can inhibit the natural nitrogen-fixation process, so use only a low-strength nitrogen fertilizer if absolutely necessary. Legumes can even be used as cover crops in the winter to prevent soil erosion and provide a boost to your soil health all winter long. You can direct-seed beans and still get production all season, meaning Connecticut gardeners can get beans in the ground now.
Fava beans (Vicia faba) are grown all around the world, very adaptable to many climates, and are generally very easy to grow. They are cold-tolerant and can be grown all the way down to USDA Hardiness Zone 3. In Connecticut, for the best results, you should plant fava bean seeds in the early spring in a place that gets full sun and doesn’t stay too moist. They will take about three months to begin producing beans but will continue producing throughout the season and into the fall. Some frost-resistant varieties will even survive temperatures below freezing, and since they self-pollinate, bees are not necessary for the production of pods. Fava beans do not require trellises, but some larger varieties may benefit from cages or trellises for additional support. In the summer, pollinators love the flowers, and understandably so – bean flowers not only signal the coming produce but are also eye-catching. Many varieties have white and dark red flowers. Some varieties have pink flowers. Bean pods can be harvested and eaten whole if they are young and tender. It is important to note that some people may have an adverse reaction to consuming fava beans, a metabolic disorder called favism. Favism causes anemia in response to the inhalation of the plant’s pollen or consumption of the beans. Be sure to check with your doctor before trying these beans for the first time.
For “summery” beans that are native to central and south America, you can try planting kidney, cranberry, appaloosa, or navy beans, all in the genus Phaseolus. Perhaps the delight of beans in the Phaseolus genera is their diversity in appearance. Appaloosa beans are especially whimsical, with white, brown, and reddish mottling. They strongly resemble the horse for which they are named. Some of these species behave like pole beans, meaning they will need to be trellised, while others behave like bushes, meaning they should not need to be trellised. The seed packet should indicate whether they will need to be trellised. As with fava beans, be sure to water Phaseolus when the soil seems dry, taking care to avoid watering the leaves. Excessive leaf wetness may increase the likelihood for fungi to grow and cause disease.
No matter what bean you try growing, pests and disease are ever-present. Aphids, bean beetles, and European corn borer are all possible bean pests. Beans are susceptible to diseases like powdery mildew, Fusarium wilt, and bean rust. Selecting disease and pest-resistant varieties will reduce the risk of yield loss. Like most legumes, the ideal soil pH for growing beans is 6-7. Since native Connecticut soil typically has a pH closer to 5.5, be sure to send a soil sample to the UConn Soil and Nutrient Analysis Lab to test the pH (and nutrients!) of your soil before planting to ensure you get accurate recommendations for any amendments your garden may need to allow beans to thrive!
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.
By Heather Zidack, UConn Home & Garden Education Center
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 athomegarden.cahnr.uconn.edu, or reach out to your local UConn Extension center atcahnr.uconn.edu/extension/locations.
The snowy weather is getting mixed reviews around the state. Some people are thrilled, others are begging for a little more sunshine and less precipitation. (Spring 2025)
