Your Raised Beds Worked Hard All Season—Garden Pros Share 6 Ways to Help Them Recover Before Winter
The Spruce – Heather Zidack and other gardening professionals recommend their top tips to help your garden beds prepare for winter.
Yard & Garden
Should You Lime This Fall?
Feeling blue? How Blue Pigments Create Vibrant Hues in Plants
Blue is a color seldom seen in nature. Although the sky and bodies of water appear blue, very few animals and plants also exhibit this striking color. Anthocyanins, a type of pigment, are responsible for creating the red, purple, and blue hues found in plants. Anthocyanins are sensitive to environmental effects, such as acidity and the presence of metal ions. A primary example of this phenomenon is seen in the primary pigment Delphinidin, a type of anthocyanin. Delphinidin changes color in the presence of aluminum ions, which become more soluble/available in acidic environments. Bigleaf hydrangeas contain this pigment, infamously lining the neighborhoods of Connecticut in a range of pastel blues to deep fuchsia hues dependent on soil pH levels.
Other plants, such as the blue oil fern, can appear iridescent blue due to structural color. Since they are accustomed to the dim understory of the rainforest, these plants must take advantage of as much light as they can get. Many plants reflect green light the most, creating their characteristic green hue. Blue oil ferns have specialized chloroplasts on the surface of their leaves called iridoplasts, allowing the plant to capture more green light rather than reflect it. These iridoplasts create a shiny blue appearance despite no blue pigments being present. The arrangement of photosynthetic membranes in iridoplasts creates an optical nanostructure known as photonic crystals that slow down and concentrate light, ultimately allowing the plant to use available light more efficiently.
Many companies have taken the rarity of blue plants as a challenge, working to engineer a blue flower themselves. Roses, orchids, and chrysanthemums have been genetically modified in recent years to achieve this goal, but the results thus far have only yielded shades of purple. One project, the Phalaenopsis Blue Gene Orchid engineered in Japan, was recently deregulated in the United States and thus approved for sale (though not yet widely available). A Delphinidin gene was inserted from an Asiatic dayflower into a pink “Wedding Promenade” orchid. A white orchid flower, an apparent blank canvas, could not be used as a starting point because Delphinidin needs co-pigments to bind and stabilize the color—White Phalaenopsis lacks these important support molecules. The Blue Gene Orchid flowers in a deep purple-indigo, likely due to its intracellular pH and naturally occurring co-pigments that bind and alter coloration.
The easiest method, however, to acquire blue flowers may be available in your kitchen: food coloring. If you place cut flowers into a cup of water with blue food coloring (20-30 drops), the water will be sucked up through water transport tubes (xylem), giving your flowers a pleasant blue coloring. While artificial, it allows for unique customization and can be a great experiment to do with kids. White carnations and roses worked best when I attempted this for my second-grade science fair. Grocery stores selling blue flowers often use this trick via stem injection or may also paint blue coloring on the outside of the flower. While a standalone blue pigment doesn’t exist in plants, nature has found a way to create a beautiful rainbow for us to enjoy!
Gardening Season Isn’t Over Yet: 6 Fast-Growing Flowers You Can Still Grow Through the Start of Fall
Gardening Season Isn’t Over Yet: 6 Fast-Growing Flowers You Can Still Grow Through the Start of Fall
The Spruce – Heather Zidack joins other gardening professionals to recommend fall blooming annuals for extending your season of color.
Vascular Invaders – Verticillium and Botryosphaeria fungi
Vascular plant diseases present a complex series of challenges, both in diagnosis and management. Pathogens of this nature invade the roots and vascular system of their host, stifling the ability of water and essential nutrients to travel throughout the plant. Without proper vascular function, leaves become yellow and wilted. Abnormal discoloration and the pattern which it forms within stem or branch tissue is often the key indication that a vascular disease may be present.
Two of the most prominent vascular pathogens are fungal species of Verticillium or Botryosphaeria. Both infect a wide array of hosts, overlapping to encompass many ornamental trees, shrubs, and vegetable crops. While there are many similarities between the diseases these pathogens cause, there are also defining characteristics which distinguish one from the other.
Verticillium dahliae and verticillium albo-atrum have the potential to cause verticillium wilt. Hosts span from vegetables like tomatoes and potatoes to trees like maple and ash. The fungal structures of either species inhabit soil where infected plant debris has decomposed. There, they can survive for 10-15 years. During the pathogen’s dormant phase, survival structures called microsclerotia germinate. Hyphae (filamentous fungal growth structures) are emitted from these structures and can extend to potential hosts within limited distances. Verticillium inoculates hosts by entering root tips or other areas of root formation, breaking through exterior layers to reach the vascular tissue inside. Conidia (spores) are formed in this location, dispersing to other potential hosts, while Verticillium continues to spread throughout the plant.
Although Verticillium wilt symptoms differ among hosts, abnormalities like leaf yellowing (chlorosis) or browning, wilting, and branch dieback raise suspicion of infection across the board. Symptoms may be isolated to one side of the plant or individual branches. Branch or stem discoloration is another key indicator of infection, accompanied by a streaking and a characteristic ring-shaped brown pattern on the interior of woody tissue. Damage is often concentrated in the lower areas of the plant, as Verticillium invades hosts from their base, working upwards.
The persistence and longevity of Verticillium structures in soil makes crop rotation and the destruction of diseased tissue crucial to disease management. While it’s usually best to remove the diseased plant entirely, woody plants with minor infections can survive for several more years, provided affected branches are pruned away and tools used for pruning are disinfected after use. Rubbing alcohol is a good choice, but there are several other disinfectants on the market labeled for use with tools. Do not compost or use diseased tissue for wood chips, as remaining fungal structures will survive for several years and may infect new host plants.
Botryosphaeria canker and dieback are attributed to several causal agents in the Botryosphaeriaceae family. Botryosphaeria is an opportunistic pathogen, choosing already stressed plants to infect and taking advantage of their weakened defense systems. Stress can stem from many sources—frequently environmental challenges, insect infestations, or prior instances of disease. While this group of pathogens has an extensive range of hosts, it is often observed on woody ornamentals—viburnum or rhododendron, for example—and trees like dogwood or maple. Fungal structures overwinter on previously infected tissue, or as endophytes which silently colonize plants without causing symptoms until they become weakened. Botryosphaeria uses many routes of entry when invading its hosts, including open wounds, cracks, or lenticels—porous openings on branch and stem tissue used for gas exchange.
As a vascular pathogen, wilting and dieback are characteristic symptoms of disease, accompanied by necrotic patches on bark and branches. Branches become girdled, and sunken cankers are evident. Depending on the host, sap may ooze from these areas, and black fungal sporulation (pycnidia) may be visible. Unlike verticillium wilt, interior vascular discoloration due to Botryosphaeria infection appears in wedges, resembling a slice of pie.
To manage Botryosphaeria canker and dieback, it is important to minimize sources of stress which can leave plants susceptible to infection. Appropriate pruning and sanitation practices, routine fertilization in accordance with the plant’s needs, and protection from environmental stressors (drought, heat, or cold) are all vital to maintaining vigor. Take care to prevent mechanical injury and wounds, minimizing the potential modes of entry for the pathogen.
As is the case with all plant diseases, laboratory analysis is required for an accurate diagnosis. If you suspect your plant has been infected by a vascular disease, submit branch tissue to the UConn Plant Diagnostic Laboratory for evaluation. Remember to collect tissue that is just beginning to appear symptomatic, as the lab is unable to diagnose plants that are already dead.
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.
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!
Chaos Gardening
Chaos gardening is a growing social media trend that encourages gardeners to relinquish control, scatter assorted seeds, step back, and see what happens. Instead of carefully spacing plants and planning layouts, chaos gardeners toss seeds and let nature decide what grows where. The results can vary widely, ranging from a surprising assortment of plants to a patch of disappointment.
Unlike traditional gardening, this approach emphasizes spontaneity over structure. For many, the appeal lies in its simplicity. Chaos gardening is easy to start, requires minimal knowledge, and often relies on leftover or inexpensive seed packets. The low-stakes, experimental nature makes it especially attractive to busy people or those new to gardening.
Still, the trend raises valid questions. Without site preparation or ongoing care, how well can seeds establish? And does “letting go” invite weeds into the garden under the guise of wildscaping?
In practice, chaos gardening often produces mixed results. While the concept is appealingly simple, success rates can be low, and plantings may struggle to persist long term. Still, gardeners interested in the trend can improve their chances of success by following a few simple suggestions.
Avoid using this approach in large or prominent spaces. Start small, either in a container or a less visible area of the yard. To maintain a sense of experimentation, while increasing success, consider focusing on a single species at a time or scattering spring bulbs through an existing lawn. Tossing out a packet of “wildflower” seeds may sound charming, but it will not produce an instant, picture-perfect meadow. More often, it results in a steadfast patch of mugwort.
Even with a relaxed approach, a bit of planning goes a long way. Key factors such as sunlight and soil conditions still matter. The principle of “right plant, right place” applies regardless of gardening style. Identifying site conditions, selecting appropriate species, and preparing the planting bed can significantly improve outcomes.
Gardeners should also approach seed mixes labeled “wildflower,” “pollinator-friendly,” or “native” with some caution. While not inherently problematic, these mixes can contain species that are poorly suited to local conditions. A quick review of the species on the list can help inform decisions about whether the plants are suited to the region or growing conditions.
Learning how to recognize seedlings, including common weeds and invasive plants, is another important step. Early identification allows gardeners to remove undesirable species before they establish. Observing which plants succeed can also guide future efforts, gradually transforming a disorderly patch into a more reliable and productive space.
Patience is essential. Many perennials grown from seed take more than one season to flower. Including a mix of annuals and perennials can help maintain visual interest while longer-lived plants establish. As with any gardening method, some trial and error is expected.
Chaos gardening may never replace traditional approaches, but it offers an accessible entry point for beginners and a creative outlet for experienced growers. With a balance of spontaneity and informed decision-making, even an unstructured planting can become a living experiment.
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.