The Spruce – Heather Zidack discusses why container mixes dry out so fast and how to maintain healthy container gardens.
Plant Health
Tree Burls
Burls are sound, hard, woody swellings or protrusions that form on the trunks, branches, or roots of trees. They often appear as rounded or ridged masses with normal bark tissue. Burls are benign and are the result of a response in growth to outside stresses. The normal bark texture of the tree will be on the exterior surface of the burl.
The exact cause of burl formation is a mystery, but these growths are formed by abnormal cell proliferation by the xylem. This growth can be triggered by stress factors such as environmental injury, insect feeding damage, or infections from fungal or bacterial pathogens. Some are thought to be the result of genetic factors that trigger abnormal growth without outside influences. Most burls are not causes of concern to the health of otherwise normally growing trees. Removal of burls from trees is not recommended as it will cause more harm than if the burl remains on the tree.
Some tree species seem to have more burls than others. In our area oaks, maples, willows, cherry and elms have more of a tendency to form burls than other tree species. Sometimes small groups of the same tree species in a tight area may all have burls. Whether the cause is environmental, genetic or both would require a good amount of research. Even then, the root cause may be impossible to discover.
Recently, a friend showed me a tree with one of the largest burls I have seen. This tree was located about a mile into the woods and was a good distance from the trail, but easily visible. It was almost five feet high and went almost completely around the trunk of the mature tree it was growing on.
Because of the nature of unique formation and structure of burls, grain formation is unusual, creating swirling patterns that can be very beautiful. A bird’s eye pattern is the result of an aborted adventitious bud. This makes wood galls a highly prized find by woodworkers, who use the wood especially for veneers and bowls.
There are woody galls caused by gall- forming mites, wasps or by fungal pathogens that are sometimes mistaken for burls. These include the black knot galls that form on infected black cherry and other Prunus species and are caused by a fungal pathogen, as well as horned galls on oaks that result from feeding by gall wasps. These types of growths can be harmful to the host tree.
To tell if an abnormal growth on a tree is a burl or a gall, compare the outer surface and texture of the growth. Burls have smooth, rounded surfaces that are fully covered in bark. The tissue is solid wood and will have intricate, swirling grain patterns. Galls typically have a rough texture to their surface, somewhat tumor-like and with vertical or horizontal ridges. The interior is not solid wood, but instead may be papery, pulpy or otherwise somewhat softer than the wood and is usually discolored. If cut open, there may be a wasp larva or a mite inside the gall. While both a gall and a burl result from excessive cell division, the causes are very different.
If you want to learn more, a good article on tree burls can be found on this link from the University of New Hampshire written by forestry field specialist Greg Jordan.
The UConn Home Garden Education Office 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 extension.uconn.edu/locations.
Water your CT Garden with Confidence
Watering is an essential skill for gardeners that is often overlooked. “How often should I water and how much?” is a frequent question with new gardens or when establishing new plants.
There’s no magic formula for watering your plants. The soil texture, local climate, and even the metabolism of your plants can affect how often water needs to be replenished. So how do we know what to do? Over time, experienced gardeners form a sense of their soil and their plant’s needs, and perfect their watering practices.
What plants really need
Most established garden plants require about 1 inch of water per week from rainfall and irrigation combined. When mother nature doesn’t provide this through rainfall, we can supplement by adding about 0.62 gallons of water per square foot in a garden bed. However, actual needs vary with soil type, weather conditions, plant species, and stage of growth.
Knowing your soil texture can help you anticipate what your watering schedule might look like. Sandy soils are known for rapid drainage, which often means they require more frequent watering. Clay soils, on the other hand, hold water for longer periods and generally need less frequent irrigation. Plants also have preferences for different soil types, many of which are related to water availability and drainage. Choosing the right plant for the right site can help ensure it receives adequate moisture.
A plant's water demand may vary depending on its stage of growth. For example, we tend to encourage additional support for plants that are fruiting/flowering, or plants that have just recently been transplanted. Keep a close eye on these plants and their water needs during stressful periods. Newly planted trees, shrubs and perennials need this additional monitoring and support through their first year of establishment in the landscape. You may find that you’re watering them more frequently during this time. This can be totally normal.
Sometimes, soil can appear dark even when it hasn’t been watered, so don’t rely on appearances alone. Your hands are one of the most reliable tools for checking soil moisture. Dig a few inches below the surface and feel the soil. If it feels cool and slightly moist, watering can likely wait. If it feels dry and crumbly, it's time to water. If the soil feels saturated or releases water when squeezed, allow it to dry somewhat before watering again.
Water Deeply
Giving your plants a good soak does more than just help them in the short term. Deep watering provides a slow, thorough soak that reaches the plant’s root zone rather than just the soil surface. This encourages deeper root growth and can improve drought tolerance, often allowing for less frequent watering. For most vegetables and perennials, water should reach at least 6–12 inches into the soil. Trees and shrubs may benefit from moisture penetrating even deeper into the root zone.
Apply water slowly at the dripline so it soaks in without pooling or running off. Use a soaker hose, or a regular hose on a slow trickle over the root zone of your plants. Avoid high-flow sprinklers, since they may cause runoff. Keep in mind that water movement depends on soil type.
Check the soil every so often to ensure that water is penetrating deep enough and set a timer for yourself. After a few watering cycles, you will become familiar with the timing and flow rate for your specific soil and plants.
Stay Consistent
Don’t automatically change your watering habits just because the temperature changes. Hot weather can increase water demand, but it is essential to always check the soil first. During periods of heat and drought stress, plants can close their stomata and reduce water use as a survival mechanism. While this may slow water uptake, plants still need adequate soil moisture. Overwatering, however, may not be helpful. Instead, roots can sit in saturated soil and develop diseases like root rot. Always check the top few inches of soil to ensure water is needed.
When weather starts to cool off in the fall, continue your watering practices. By watering until the ground freezes, you help your plants, survive the winter. The effects of winter burn can be reduced when evergreens enter the winter properly hydrated.
Watering is an essential task in the garden year-round. It is important to know your plants, your soil, and the climate you are growing in to ensure you are giving your plants enough hydration. By watering only when needed, watering deeply, and continuing these practices well into the fall, you will be sure to have healthy plants year round!
The UConn Home Garden Education Office 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 extension.uconn.edu/locations.
What’s Going Down with Your CT Basil This Summer?
Managing Invasive Plants
Episode 166: Managing Invasive Plants
UConn 360– Lauren Kurtz discusses invasive plant management and the new Invasive Species Certificate Program.
Wet and Wild: the Complex Lives of Cedar Rust Fungi
We all know that old saying, “April showers bring May fungi!” (No? Just me?). All joking aside, you may have noticed that the recent wet spring weather lead many fungi to break dormancy, release spores, and wind up in new places. While growers and gardeners often find themselves preparing for the season by promoting airflow between plants, increasing soil drainage, and applying preventive fungicides when really needed, it’s hard to deny the spectacle of spring fungi and the beauty they bring to our spring gardens; and few are as spectacular as cedar rusts (Again, only me?)!
Cedar rusts are flashy diseases caused by multiple species of the fungi in the genus Gymnosporangium. In the case of cedar apple rust, a disease we see all the time here in Connecticut, the causal agent is the fungus Gymnosporangium juniper-virginianae. Gymnosporangium is a group of heteroecious fungi, meaning that they require two hosts to complete their life cycles. Species within the Juniperus genus are primary hosts of cedar rusts with plants such as apple, crabapple, hawthorn, or quince usually serving as a secondary host, though close relatives such as pear or chokeberry may occasionally be seen with cedar rust.
Spores – small reproductive structures produced by fungi – are released from fungal structures to infect other hosts. Cedar rusts, attention seekers that they are, utilize multiple types of spores to get to their host plants of choice. Beginning with the secondary hosts in late summer, spores called aeciospores are produced and distributed by wind and rain, traveling to inoculate nearby juniper trees. Wet, mild weather in early fall creates the perfect conditions for these aeciospores to germinate, eventually resulting in the formation of large galls on the primary host.
Juniper galls are irregularly shaped structures on the plant and range in color from gray to dark red. Circular indentations are present on the gall’s surface, through which bizarre looking telial horns protrude in the spring the year after the host is first inoculated with the disease. These structures are first colored dark brown and have a dry appearance but later become gelatinous and bright orange as they mature and expand for a brief time during moist spring conditions. The surfaces of telial horns are coated in teliospores which later germinate to form the next important player in the cedar apple rust disease cycle, basidiospores. After releasing spores, the telial horns will dry up and fall off. The basidiospores are then distributed by wind and rain to inoculate secondary hosts such as apples or crabapples. Immature leaves with wet surfaces are the most susceptible targets for infection.
The next stage of the disease cycle kicks off with yellow-orange lesions that appear on the upper surfaces of leaves. A halo of red tissue may surround the edges of these spots, giving a dramatic bullseye appearance. Tiny, raised, fungal structures known as pycnia develop within the leaf lesions and on fruit surfaces. Pycnia produce pycniospores (notice a theme here?), which leads to the development of aecia during mid-summer. Yellow or brown lesions appear on the underside of leaves, from which the tubular aecia and of course, their aeciospore-covered surface, protrudes. During late summer under dry environmental conditions, aeciospores are released and travel to nearby juniper hosts where the disease cycle begins again.
You might be thinking, “enough with the spore-talk! What should I do about cedar rusts if I see signs of them?” Rest easy - although cedar rust fungi are complex and dramatic, they typically don’t cause lasting harm, and there are plenty of management strategies available to mitigate their damage. Pruning can be used to promote airflow and eliminate galls from junipers before telial horns have an opportunity to develop, and appropriate fungicides may be applied to secondary hosts as a preventative measure. And for those thinking of purchasing a new tree, know that many apple and crabapple cultivars are available at the nursery with various levels of resistance to cedar rust.
Have a question about plants? The UConn Home Garden Education Office 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 extension.uconn.edu/locations.
Do Eggshells Actually Help Your Roses Grow? Here’s What a Gardener Says
Do Eggshells Actually Help Your Roses Grow? Here’s What a Gardener Says
The Spruce – Heather Zidack discusses how Egg Shells are best used in the garden, and things to consider before adding them!
Wait, Why the Heck Are People Putting Pennies in Their Houseplants’ Soil?
Wait, Why the Heck Are People Putting Pennies in Their Houseplants’ Soil?
The Spruce – Heather Zidack educates readers on whether putting a penny in potting soil really keeps away pests and disease.
Beech Bark Disease – One More Problem For Connecticut Beech Trees
American beeches have been suffering from beech leaf disease that is widespread in both Connecticut landscapes and forests. The prognosis for this disease is currently uncertain, but research is investigating treatments and other methods for possible control. This disease is evident from dark bands appearing on the leaves, so homeowners can to some extent seek help from licensed arborists once this symptom is evident.
Meanwhile, beech bark disease is also becoming a major threat to American beech (Fagus grandifolia) in eastern North America. This disease is a result of an interaction between a scale insect and one of two Nectria fungal pathogens. When these scales are present, beech bark disease has an increased chance of infecting the tree. The scale responsible was introduced from Europe and first appeared in Nova Scotia around 1890, according to researchers. Within forty years, the fungal pathogen combined with heavy infestations of the beech scale were killing trees, although only in Eastern Canada and Maine.
The scale insect, Cryptococcus fagisuga, will attack American beech, European beech (Fagus sylvatica) as well as Chinese and Oriental beeches, F. enleriana and F. orientalis, respectively. The scale insects pierce through the thin bark of the beeches with a stylet and inject enzymes to help digest the plant material. These small wounds in the tree can now be the entry point of fungal pathogens, including the two native Nectria spp. that can cause beech bark disease.
Adults mate and females lay eggs in mid- summer. Eggs hatch from late summer until early winter and form a waxy white covering. These scale insects often go unnoticed until they develop a “woolly” appearance which is evident in the winter. The immature scales overwinter on the tree, and the next year will become adults. If you notice white woolly scale insects on beeches, especially on trunks, these are likely the beech bark scale. In two to three years, scale populations can reach high levels where the trunks may appear white. Scales do not have wings, but they can be blown by the wind to new trees or transported by birds or even humans.
Disease symptoms take several years to develop after scales appear. Anyone hiking through the forests of Connecticut has probably noticed disfigured bark caused by the Nectria pathogens responsible for beech bark disease. In severely infected trees, living tissue just beneath the outer bark is killed. Cankers appear looking like rough, raised, circular disks. Fungal fruiting bodies appear in the center of these raised circles. Sometimes there are so many red fruiting bodies of the fungus that large areas of the trunk appear red. Over time, bark may crack and split off. Trunks of weakened trees can snap in high wind events. Nectria kills areas of woody tissue, sometimes creating cankers on the tree stem and large branches which in turn weaken the tree. Infected trees can thus be susceptible to other diseases and insects.
So, this is not a happy tale, but homeowners do have some good news. Controlling the scale on any ornamental or native beeches on a property resulting in the absence of these scale insects will prevent beech bark disease. Because beech can form thick stands, thin some smaller trees out so the remaining trees will retain vigor. Make sure trees that have no scale present, and no disfigured bark are left with good space between them.
In case you may need an arborist, the Connecticut Tree Protective Association has licensed arborists that can help you assess the situation with your trees. A licensed arborist will be the best choice in any case. They will be educated in tree insect and disease problems and their solutions, if any are available. Contact the Connecticut Agricultural Experiment Station Forestry and Horticulture department for the latest news and control options for disease and insect problems. Hopefully, your beech trees will never have problems.
The UConn Home Garden Education Office 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 extension.uconn.edu/locations.
Chestnuts: A Tasty Thanksgiving Treat
With Thanksgiving approaching, many of us will be sitting down to hearty feasts with family and friends. Time-tested recipes on worn index cards or heavily thumbed cookbooks are combed through/uncovered. Many of us gardeners pick a few new plants for our gardens each year, so why not try a new plant on the dinner table? Chestnuts were reputedly served at the first Thanksgiving and thanks to dedicated breeding programs may be available locally today.
It’s hard to imagine that a little over 125 years ago there were probably 4 billion American chestnuts (Castanea dentata) spread out from southern Maine to northern Georgia. They were an important food source for both indigenous people as well as wildlife. Early European settlers found their rot resistant wood useful for many building purposes.
Unfortunately, a disease (Cryphonectria parasitica), known as chestnut blight, was unintentionally introduced in 1876 on imported Japanese chestnuts (C. crenata). These were sold via mail order throughout the eastern U.S., and our native American chestnuts soon became infected. This fungus spreads by windblown spores. Signs of infection include a reddish-orange ‘rash’ on the affected bark and as it reproduces, an orangey substance oozes from pores in the bark. Cankers form and eventually the plant can no longer internally transport water and nutrients. Chestnut blight kills the parent tree but not the roots so even to this day, you are able to find sprouts growing from chestnut roots. As the sprouts develop, they too will be killed back by the blight so while the tree is kept alive, American chestnuts are considered functionally extinct, but all is not lost.
Fortunately, both researchers and chestnut lovers have been working pretty much for the past 100 years on developing varieties resistant to chestnut blight. Breeding work has been done in many locations but the Connecticut Agricultural Experiment Station began their program in the early 1900s and it is the only program that has continued uninterrupted to this day. Presently this CAES program is led by Forest Pathologist and Ecologist, Dr. Susanna Kerio.
Various chestnut species including American, Chinese Japanese and European have been crossed, backcrossed, planted, evaluated, culled and selected by researchers and enthusiasts all over the eastern U.S. As one can imagine, it takes more time to evaluate a tree’s characteristics than say, an annual plant like a tomato.
Organizations like The American Chestnut Foundation started in 1982 have been championing the search. According to Deni Ranguelova, the New England Regional Science Coordinator, the goal is to develop blight resistant chestnuts and restore this magnificent tree to its native range. Members of this organization have the opportunity to obtain straight species or hybrid seed to try their hand at growing chestnuts and add observations to the chestnut knowledge base.
Why all this work on chestnuts? Well for one, they are deliciously mild and sweet. They are low in calories and high in fiber. Chestnuts are a good source of potassium and other nutrients. Eat them freshly roasted (just like in the song!), in holiday stuffings, soups, in main dishes and glazed. To cook them, they do need to be scored whether oven roasted, boiled, steamed or microwaved to keep them from bursting. Lots of instructions, recipes and videos can be found online.
Second, plants are productive. In fact, it was estimated that before their demise that a mature American chestnut may be able to produce 6000 nuts! They can serve as a food source to both people and wildlife as researchers and enthusiasts create blight resistant strains to plant in our natural areas or in commercial orchards.
Aside from being a member of The American Chestnut Foundation and obtaining seed, one can order chestnut seedlings from several online nurseries. Keep in mind that chestnuts do best in a sunny area with well-drained soil. Root rots can occur in poorly drained areas. Plants are being bred to be straight and tall for timber, or shorter and wider for nut production. Make sure you have enough space for a mature chestnut tree, or most likely 2 trees as chestnuts need another plant for cross pollination.
Even if a chestnut tree is not in your future, do try some chestnut dishes at your Thanksgiving table. They may start a new tradition.
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 extension.uconn.edu/locations.