The spots start off in the spring on top of the leaves as small yellow areas. These spots may remain relatively small, or may enlarge over the growing season to approximately 3 ∕ 4 inch in diameter. The larvae feed in groups and eat entire leaves, leaving only the mid-veins, defoliating an entire branch before moving to another. While not life-threatening, tar spot is a fungal infection that affects maple tree leaves. Frequently Asked Questions About Black Spots on Maple Tree Leaves. It's leaves are turning black and withering. A fungus is causing black spots on maple tree leaves. Instead, it’s recommended that the homeowner rake up the affected leaves and dispose of them in a way that will prevent the fungal spores from overwintering. As spots mature, the centers may fall out, leaving roughly circular holes. Sign up now! Fungal Disease Doesn't Affect A Tree's Health, Just Its Appearance. The fungus winters-over on fallen leaves. Tar spots on the maple leaves develop as a small yellow spot and turn black afterwards. × View full size in a new window. Tar leaf spot diseases that occur on our native maple species are occasionally observed, but cause inconsequential damage. It belongs to the genus Rhytisma. Purple-bordered leaf spot leads to the formation of roughly circular dead areas (typically less than ¼ inch in diameter) on maple leaves. Black spot disease is diagnosed when black or brown spots appear on leaves.. Leaf blister and anthracnose can occur on the same tree and even on the same leaf. Q. I noticed that the maples in my neighborhood have black spots on them. ), appears as black, sunken lesions. Everything you need to know about those black spots taking over some maple leaves by Lauren Abbate September 16, 2017 September 18, 2017. As its name implies, tar spot disease looks like big black tar spots on the top of the leaves. It is not until mid to late summer that the darker coloration of the spots shows up. Since maple tar spot affects only the appearance of the tree and not its health, Johnson said that treatment is not necessary. Today's news and more in your inbox Sign up Now! On older leaves, spots enlarge slowly. 'Tar spots' appear on some maple tree leaves. The fungus responsible for the tar spots on the leaves of the tree is the most harmless maple tree fungus. Verticillium wilt: Early symptoms of verticillium wilt include heavy seed production, leaves that are smaller than normal, and browning of the margins of leaves. It has been dropping these leaves for about two weeks. If you take a close look at the trees in your yard, you may notice signs such as black spots on the leaves. 1 Response. If the leaves are not raked up in the fall, the fungal spores will reappear in the spring and spread to nearby trees. Velvety, felt-like patches, formed of numerous microscopic galls amid the leaf hairs on the underside of the leaves, occur on sugar, silver and red maple, and occasionally Norway maple. These spots are caused by a fungal disease aptly called Tar Spot. All About Maple Tar Spot, the Black Spots on Your Maple Trees Share this Post: Share on facebook Share on twitter Share on googleplus Share on linkedin Share on pinterest I recently was conducting some training classes with the Field Service Professionals in Mequon, WI and I saw a tree disease that seems to be increasing in frequency over the last couple of years – Maple Tar Spot. I have other hard maple trees with no leaf problems. The spots eventually merge and cover the entire surface of infected foliage. Will the tree die or will it survive? The tree is about twenty five years old. An EEO/AA employer, University of Wisconsin-Madison Division of Extension provides equal opportunities in employment and programming, including Title VI, Title IX, the Americans with Disabilities Act (ADA) and Section 504 of the Rehabilitation Act requirements. Maples are deciduous trees characterized by opposite leaf arrangement and spectacular fall color. One of the things many maple tree owners see is that the leaves start producing black spots on them. The black spots are fairly unsightly, but they don’t do any harm to your trees and will be shed when the leaves fall. Connect with your County Extension Office », Find an Extension employee in our staff directory », Get the latest news and updates on Extension's work around the state, Feedback, questions or accessibility issues: info@extension.wisc.edu | © 2020 The Board of Regents of the University of Wisconsin System Privacy Policy | Non-Discrimination Policy | Discrimination and Harassment Complaints | Disability Accommodation Requests | Civil Rights. The causal agent is the fungus Taphrina carveri. Maple leaves have black spots. Have you noticed black splotches on the leaves of your maple tree this year? This is actually a harmless autumn blaze maple disease that is caused by fungus and pathogens. We have several maples where the edges of the leaves are turning black. My 10 year old maple tree is not doing well this year. Maple leaves are quite common in Toronto. Maple Tree Branches Dying. Every spring and summer, we get calls from Milwaukee area homeowners concerned about black spots on the leaves of their maple trees. In many cases, these leaves with the black spots are dropping early, which adds to the concern. Any ideas what it is or what I can do? As tar spot develops, black structures (resembling blobs of … The flowers are upright and green, yellow, or red in color depending on species, and the fruit appears in winged clusters which hold the seeds of this self-pollinating tree. Black Spots on Soft Maple Leaves (WI) From: James Wagner City: Wauzeka, WI: I have a soft maple tree that has some of the leaves turning black with holes in them. Both of these Rhytisma species form black spots on maple leaves late in the season (September and October until leaf fall is a good time to observe tar spot in the northern latitudes). This occurs when the tree loses water from its leaves faster than it can absorb it from the soil. Defoliated trees should be watered (about one inch of water per week), and properly fertilized (based on a soil nutrient test). Unsightly black spots on maple leaves won’t harm trees. … Spores produced on infected leaves can lead to additional infections within the tree canopy throughout the growing season. Is there a treatment for black spots on maple tree leaves? thestar.com - A lot of maple leaves that have fallen lately have black spots on them that make it look like the trees that shed them may be sick. Spots have tan to brown centers and distinct purple, red, or brown margins. Gather and burn all the leaves to eliminate any chance of having the fungus survive. These develop into brown-black lesions, retaining the yellow border. Maple dieback includes symptoms such as dead twigs or branch tips and dead areas in the canopy. Maple tar spot rarely does any damage to the tree’s health. The good news is that while this disease causes blotchy brown spots to pop up on the tree’s leaves, it doesn’t impact the tree’s overall health. inch) yellowish spots that form on infected leaves. At this stage, the leaf spots are light green to yellow green. Same this year. Tiny, black, pimple-like reproductive structures (called pycnidia) often form within the spots, and are diagnostic. Infested leaves rot and fall from the tree as the tissue decay worsens. The ¼-3/8” mat-like galls begin light green or yellow-green and often become more conspicuous when they change to a bright red or crimson. This action can minimize fungal spores to infect the following spring. Eventually the entire leaf dies. Lesions are a mix of lighter brown to black. In the spring, rain and wind move spores of the fungus from the leaf litter to newly developing maple leaves, where infections occur. Tar spot is one of the most readily visible and easiest maple diseases to diagnose. The fungus takes control of the tree when the tree suffers ongoing weakness brought on from maple tree decline. Steganosporium ovatum cankers appear as a secondary infection on the maple tree. The pathogenic fungus is responsible for the untimely fall of the leaves. Their diameter can be about an inch or more; and they can be found on the seeds (samaras) too. Compost, bury or burn leaf litter from infected trees in the fall, or in the spring before trees releaf. These photos show a range of symptoms presented by this disease. Unsightly Black Spot On Maple Leaves Will Not Harm Trees published September 15 2020 5:01 PM SPRINGFIELD - If you’re seeing spots on maple trees, you are not alone. One species produces tiny black spots that later coalesce into larger black spots … Black spots on maple tree leaves treating black spots on maple leaves brown spots on maple tree leaves maple tar spot disease learn about the. Compared with maple anthracnose, the spots are more rounded in shape and contain small, raised blisters. The most common species are Rhytisma acerinum and R. punctatum. Healthy maples often recover, suffering only … Anthracnose primarily occurs during stretches of cool, rainy spring weather. Lesions are a mix of lighter brown to black. Buds may fail to open or may turn black and die shortly after opening. As tar spot , black structures develops (resembling blobs of tar) form. Then, they progress to the black spots on the leaves you see above. Tar spots on the maple leaves develop as a small yellow spot and turn black afterwards. Leaves that change to fall colors before the end of summer are a sure indication of decline. It can be easily identified. Can anything be done to prevent it? The tree was very healthy and is about forty feet high with a good solid trunk and has a good amount of leaves … The spots can also appear on the seeds (samaras). Sign up for our free newsletters now. The fungal pathogens (Gloeosporium spp.) What exactly is maple … These spots are not actually “tar” on maple, but are rather a fungal disease known as tar spot. The leaves will appear green in spring and then change color to a beautiful yellow, orange and red in fall. It starts with small yellow spots on growing leaves, and by late summer these yellow spots expand into large black blotches that look like tar has been dropped on the leaves. The fungus winters-over on fallen leaves. By mid-July, the spots expand and a thick, raised, black stomata starts to form. Oval to irregularly shaped, shiny, black spots up to ½ inch in diameter form on the leaves of silver or red maples. What is causing this, and what can I do to help the tree? Sooty Mold. The University of Wisconsin-Madison Plant Disease Diagnostic Lab has a fact sheet on Maple tar spot here. At first the infected tissue is light green or yellow. Based on your description, it sounds like the trees are infected with maple leaf tar spot, known scientifically as species of Rhytisma fungi. On Japanese maple, lesions occur along primary veins and leaf margins and appear as tan-colored, papery spots. You're not alone. Rhytisma acerinum or R. punctatum: No control measures are necessary. cause small, red-brown or tan spots to appear on the leaves. © 2020 by Wisconsin Public Radio, a service of the Wisconsin Educational Communications Board and the University of Wisconsin-Madison. Three kinds of fungi cause black leaf diseases on aspen trees. Diseases caused by Marssonina and Septoria fungi begin as small black spots that grow and eventually join, forming large, black, dead spots on the trees' leaves. A foliar disease called leaf blister has been common on silver and red maples and their hybrids during the past few weeks. The symptoms of tar spot will appear in mid-June as small, pale yellow spots. The spots enlarge and they slowly turn into black spots. She said affected leaves generally remain on the tree as usual, but a severe case can result in some leaf drop. Then, during late summer, raised, shining black, tar-like dots develop within the yellow spots on the upper leaf surfaces. There are some differences on what the spots may end up looking like at maturity, depending on the species of maple on which it is growing. The disease doesn’t prove to be harmful to the health of the autumn blaze maple but it surely creates ugly looking tar spots on the leaves of the plants. Their size ranges from one-eighth of an inch to an inch or more in diameter on the Norway Maple. In any case most blistering on the leaves by fungi or by insect damage does not affect tree health and is considered cosmetic. I too have this problem with my silver maple but my issue has been slightly different. Symptoms: Begins as yellow spots on leaves before turning into black, tar-like spots Causes: The Rhytisma fungus Treatment: None. maple tree leaves turning black. Early Fall Color. But that’s about the extent of the issue. Currently not found in Wisconsin. Compared with maple anthracnose, the spots are more rounded in shape and contain small, raised blisters. If there are fewer leaves than normal, that’s another telltale sign. But the ugly … Brown leaf edges on maples and other trees are symptoms of scorch. with black spots, scarlet hind wings with black spots, and have bright yellow abdomen with black stripe. Black spot disease on other plants; The solution to eliminating black spots on maple. The spots can also appear on the seeds (samaras). You can also put them in the compost. This occurs when the tree loses water from its leaves faster than it can absorb it from the soil. A. It can be disheartening when tarry spots appear on the leaves of sycamore trees (Platanus spp. They usually occur in periodic outbreaks of a few years at a time, though the interval between outbreaks and how long that outbreak lasts depends on the species and environmental conditions. Tar spots on maples are caused by fungi in the genus Rhytisma. Various caterpillars consume maple leaves. For questions or comments about our programming, contact WPR’s Audience Services at 1-800-747-7444, email to listener@wpr.org or use our Listener Feedback form. Edges of Maple Leaves Turning Black. Leaves can have one to several spots of varying sizes at a time, which may lead to premature leaf drop. Any ideas? For technical questions or comments about WPR’s website, streaming or other digital media products, please use our Website Feedback form. The black spot of maple leaves can be sprayed with fungicides, but many do not succeed. These leaves are from a Blaze Maple, planted about 5 years ago. It's been growing nicely but last year I didn't get a lot of leaves and early in the spring it produced a lot of seeds. The most effective way is to collect fallen leaves and destroy them. On Norway maple, the black structures are typically numerous, small (approximately 1 ∕ 8 Wisconsin homeowners might be alarmed to see a maple tree’s leaves developing dark spots — but according to Lisa Johnson, it’s likely not as bad as it looks. Maple tar spot is mostly a cosmetic issue. The spot can grow up to 1.5 inches (4 cm) in diameter. We teach, learn, lead and serve, connecting people with the University of Wisconsin, and engaging with them in transforming lives and communities. Then, they progress to the black spots on the leaves you see above. Three treatments may be needed for adequate control: one at bud break, one when leaves are half expanded, and one when leaves are fully expanded. Tar spot of maple. R. acerinum forms comparatively few, large spots on a given leaf, while R. punctatum forms clusters of many, small ("punctate") spots. Maple Leaf Blister: Black Leaves on Maple Explained. Spots have tan to brown centers and distinct purple, red, or brown margins. Rhytisma fungi cause a variety of tar spots on maple leaves that are nonlethal but unsightly. But there is also a gap, if only one leaf containing the fungus is not destroyed then the fungus will easily move to another leaf in your maple tree. Treating Black Spots On Maple Leaves Naturally Prevention Black Dots On Maple Tar Spot Msu Extension Maple Tar Spot Disease Learn About The Control Of Why Do My Maple Leaves Have Spots Msu Extension Unsightly Black Spots On Maple Trees Mostly Cosmetic Toledo Blade Why Do My Maple Leaves Have Spots Msu Extension Maple Leaf Blister Black Leaves On Explained Horticulture Maple Tree Leaves … This is the first year that this has happened. The first tar spot symptoms usually show up in early summer as small (less than 1/8 inch diameter), light-green to yellowish-green spots. Newly planted maples, and established maples that have been severely affected by purple-bordered leaf spot for several years, may benefit from treatments with a fungicide containing chlorothalonil, copper, mancozeb, neem oil, sulfur or thiophanate-methyl. It’s also one of the least damaging ailments on its host. Rake and destroy leaves in … Brown spots appearing on maple tree leaves or on the leaves of box elder trees are typically caused by something known as tar spot. Colonies of black, calico, cottony maple or painted maple aphids congregate on maple leaves to consume sap. By Fanny Iriarte, Tom Harrington and Mark Gleason, Department of Plant Pathology . Their diameter can be about an inch or more; and they can be found on the seeds (samaras) too. The spots quickly grow and kill large sections of leaf tissue. Maple Tree leaves have big brown/black spots on all of leaves. MAPLE LEAF TAR SPOT - Early signs of this normally-late-season leaf blight disease of maple were observed this week on Freeman and Norway maples in southern and western Wisconsin. How do I avoid problems with purple-bordered leaf spot in the future?If available, select maple varieties that are resistant to purple-bordered leaf spot. This is because a fungal pathogen in the genus Rhytisma has taken hold. Be sure to read and follow all label instructions of the fungicide that you select to insure that you use the fungicide in the safest and most effective manner possible. Can you tell me what is causing this and if there is anything that can be done to help this tree? Also, look for leaves that are too light in color or look burnt. My maple tree has dying branches and leaves that are shriveling up, they have black spots on them. Unfortunately, maple tree tar spot is spread on the wind, which means that your tree can get reinfected next year if spores happen to hitch a ride on the right breeze. Description: Tar spot is an ugly but mostly harmless disease that strikes several maple species. There are several common things that could be described as blister. Appears to be spreading to my 2 other maples. Lesions on Norway maple tend to be narrow, purplish-black streaks along leaf veins. How it spreads: Infection typically begins in early spring and continues into the early summer. What does purple-bordered leaf spot look like?Purple-bordered leaf spot leads to the formation of roughly circular dead areas (typically less than ¼ inch in diameter) on maple leaves. Small, black, tar-like raised structures form on the upper surface within these yellow spots. Their size ranges from one-eighth of an inch to an inch or more in diameter on the Norway Maple. Don’t worry, though; the fungus only attacks the leaves, leaving the rest of your maple tree alone. URBANA, Ill. – If you’re seeing spots on maple trees, you are not alone. The fungus is not dangerous to people or pets and doesn't affect the tree's health, an arborist told WISN 12 News. Tiny, black, pimple-like reproductive structures (called pycnidia) often form within the spots, and are diagnostic. The disease anthracnose (caused by Colletotrichum spp. Flower clusters also may be infected and rapidly blighted and blackened. The leaves are covered with black patches on the interior of the leaf. Keep updated on the latest news and information. My Crimson King Maple has leaves that have black spots on it. Edges of Maple Leaves Turning Black. I have a total of 3 maples. She said that hot composting is effective, but if the compost pile is not likely to reach necessarily temperatures, bagging the leaves and disposing of them is a safer route. How do I save a tree with purple-bordered leaf spot?DON’T PANIC. Phyllosticta leaf spot is similar in many ways to other foliar diseases of maple such as anthracnose (see University of Wisconsin Garden Facts XHT1001) and tar spot (see University of Wisconsin Garden Facts XHT1126). If you spot the above symptoms on your tree, maple decline could be plaguing your tree. It’s fine to wait for leaves to fall naturally. The tar-like spot is a fruiting structure of the fungus. Maple Tree Types. Experts Say It May Not Last. Leaf spots and anthracnose are fairly common on viburnum … In late spring, chlorotic spots appear on tree leaves. Sometimes, several spots will run together, and the leaf may crinkle at the edge or along the mid-vein. A lot of maple leaves that have fallen lately have black spots on them that make it look like the trees that shed them may be sick. The lesions continue to grow, and by the end of summer form leaf spots that look like tar. University of Wisconsin Extension horticulture educator, WisContext: The Traditions And Transformation Of Maple Sugaring, Spring Gardening During The Coronavirus Pandemic, Climate Change Will Mean Less Wisconsin Maple Syrup, Wisconsin Sees 107 New COVID-19 Deaths, Breaking Another Daily Record, Prominent GOP Assembly Member John Nygren Stepping Down, Deer Harvest Up Nearly 16 Percent During 2020 Gun Hunting Season Despite Coronavirus Pandemic, Bucks Unveil New Jerseys Inspired By Milwaukee Rivers, Lake Michigan, Pabst Brewery Operations Leaving Milwaukee, Again, Trump Campaign Asks State Supreme Court To Overturn Biden's Wisconsin Victory. Thank you. They overwinter as prepupae in the … Tar spot, although unsightly, rarely threatens the health of the tree. Barrett Gruber*, Courtney E. Jahn*, Glen Stanosz and Brian Hudelson, UW-Madison Plant Pathology *Completed as partial fulfillment of the requirements for the graduate course: “Plant Pathology 559: Diseases of Economic Crops.” Revised:  8/13/2012 Item number:  XHT1149. Any ideas? The spots first appear as small yellow spots in June. Occasionally, the disease may defoliate trees early in the growing season, but these trees are typically able to produce new leaves within a few weeks. It's been a particularly good year for the disease, called tar spot, because of all the rain that has fallen in Wisconsin, said Brian Hudelson, director of the Plant Disease Diagnostics Clinic at the University of Wisconsin-Madison and plant pathologist at UW-Extension. The fungal disease causes black fruiting structures to cover the tree's bark. R. acerinum is an Ascomycete fungus that locally infects the leaves of trees and is a biotrophic parasite. Importance: Serious economic losses of grape, orchard, and logging industries as nymphs are known to feed upon and damage more than 70 native plant species including willow, oak, walnut, and maple. On sugar maple, lesions occur along primary veins and appear as large, brown blotches. The black … This fungal disease gets its name from the fact that the dark brown spots resemble tar. What is Maple Tar Spot Disease? 2) The rounded shape of the spots and blistering distinguish this disease from maple anthracnose, which produces irregularly shaped brown spots or blotches that follow the veins of leaves and is caused by a different fungus. (Fig. Fungal leaf spots typically occur during warm, moist summer months, and initially will occur on older foliage. The spots enlarge and color intensifies as summer progresses. The pale green-yellow larvae with black spots and a black or orange head grow up to ½ to ¾ inch long. My tree is in its' 7th year. The tree looks awful. Maple leaf blister is a disease of maple leaves that displays symptoms somewhat similar to maple anthracnose. The fungus survives the winter on fallen leaves. September 01, 2020. Where does purple-bordered leaf spot come from?Purple-bordered leaf spot is caused by the fungus Phyllosticta minima which overwinters in leaf litter. Leaf spot diseases are rarely serious on their own, but they can compound with other damaging agents, like environmental stress or insect pests, to cause permanent or fatal damage. Are the trees sick? Is My Maple Tree Dying? Johnson, a University of Wisconsin Extension horticulture educator for Dane County, said that the fungal disease known as maple tar spot has been widespread in the state this year. Norway and silver maple are the trees most susceptible to the disease, Johnson said, but other varieties are vulnerable as well. Symptoms and signs. Johnson, a University of Wisconsin Extension horticulture educator for Dane County, said that the fungal disease known as maple tar spot has been widespread in the state this year. Small Leaves. We have several maples where the edges of the leaves are turning black. Wisconsin homeowners might be alarmed to see a maple tree’s leaves developing dark spots — but according to Lisa Johnson, it’s likely not as bad as it looks. However, you may notice that the leaves have some brown or black spots in summer. Feedback, questions or accessibility issues: © 2020 The Board of Regents of the University of Wisconsin System. Early intervention can prevent a declining maple tree from dying. Maple leaf blister is a disease of maple leaves that displays symptoms somewhat similar to maple anthracnose. These spots may remain relatively small, or may enlarge over the growing season to roughly 3 ∕ 4 inch in diameter. There are some differences. There are some differences. Non-chemical control . For First Time In Months, Wisconsin's COVID-19 Cases Are Declining. A microscopic sign of the pathogen are the stroma, mats of hyphae found in the lesions. Maples that are declining may have paler, smaller and few leaves than in previous years. It also seems to be experiencing branch die back. Development of the tar spot varies by the species of pathogen. Every summer we get questions about black spots on maple leaves that look like tar. What Causes Tarlike Spots on a Sycamore Tree?. I can't see any bugs or anything. Asked May 28, 2014, 2:08 PM EDT. Firstly, Tar spot is very common on the leaves and does look like blobs of tar later in the summer. The foliage often falls from the affected trees prematurely, and the fungi overwinter in the fallen leaves. Tar spot is a very ... By mid-summer these have developed into large (up to 15mm across), slightly raised, shiny, black spots with a narrow yellow margin; Heavily-infected leaves may fall slightly early; Control. Tar spot is a fungal leaf disease that is common on maples. Rhytisma acerinum is a plant pathogen that commonly affects sycamores and maples in late summer and autumn, causing tar spot.Tar spot does not usually have an adverse effect on the trees' long-term health. Photo: Kathie Hodge (CC-BY-NC-SA). The dots bring down the look of your tree – and can even cause early leaf drop. What is purple-bordered leaf spot?Purple-bordered leaf spot (also called eye spot or Phyllosticta leaf spot) is a common, but primarily cosmetic disease that affects maples (in particular Amur, Japanese, red, silver and sugar maple). Symptoms first appear as pale yellow, raised spots on the upper leaf surfaces that later develop into distinctive black… At the beginning, these tar spots are pale yellow in color that later on turn dark. What does tar spot look like? Although purple-bordered leaf spot may look unsightly, the disease is usually only a cosmetic problem, rarely causing significant damage to mature and vigorously-growing trees. Emmet County Michigan. It impacts many trees, but doesn’t usually present any critical danger to them.. Black spot disease is a fungus that mostly attacks fruit trees like the cherry tree, walnut, grapevine, raspberry, blackcurrant, oak or red currant, certain shrubs like hydrangea and also vegetables such as cucumber, bean, pea, or tomato. Spots arise in late spring or early summer after leaves attain full size. Drought, windy conditions, and root damage or restrictions are often the cause. Brown leaf edges on maples and other trees are symptoms of scorch. Between Pandemic, Evictions And Dropping Temperatures, Homeless Shelters Anticipate A Tough Winter, Wisconsin Educational Communications Board. Maple trees occasionally contract fungal diseases, but anthracnose is the most problematic. Maple tar spot has rasied black spots that are outlined in light yellow. Do those black spots on maple leaves hurt the tree? Initial symptoms of tar spot are small (approximately 1 ∕ 8 inch) yellowish spots that form on infected leaves. We think it is Tar Spot. These trees are 40 years old and I don’t want to lose them. Maple tar spot is a very visible problem for maple trees. The tar spots that can occur on sugar maple, red maple, and our other native maple species is caused by one of two other species of Rhytisma (R. americanum, and R. punctatum). If you have the same scenario going on with your tree, don’t panic, this is a very common fungus disease called tar spot and is often seen on the Norway Maple, Silver Maple and the Freeman’s Maple. Leaves are curling up too. Humid and cool weather is favourable for the development of the disease. Every year about this time, I start receiving questions on the ugly black spots that homeowners are seeing on their maple trees. The disease largely has no effect on a tree’s health, she said, and is mainly a cosmetic issue, though “it does tend to catch people’s attention.”, She said it presents itself in the form of “large, raised black spots on the leaves.” Those spots are often surrounded by “a little yellow halo around the edge of the lesion.”.