As the temperatures warm into the 70’s and the rain chance remains good, keep an eye open for disease in your lawn. Large patch disease is common in turfgrass this time of the year. It is caused by the fungus Rhizoctonia solani. The fungus is present in the soil and thatch layer year-round. When the temperatures rise into the 60’s and 70’s it begins to spread. Large patch thrives under these conditions, especially when the soil is wet. With frequent showers the disease spreads quickly. The first symptom of large patch is circular, discolored areas within the lawn. The outer borders of the patches are orange to yellowish in color. In the center of the circle there are grass blades trying to green up again. They are usually unsuccessful, resulting in odd-shaped patches of dying grass that begin to connect to each other. A simple field diagnostic techniques to confirm large patch disease is to pull on the diseased grass shoots near the edge of the circle. The blades will come loose from the stolon easily. At the base of the leaves the stem and sheaths will appear dark brown and rotten. Yes, it is large patch. If the weather gets colder or hotter very quickly, the disease will go back into dormancy. Looking at the long range temperature predictions, cool night and warm days are likely to continue for awhile. So, start looking for a fungicide or two or contact your pest control service. However, remember fungicides don’t cure existing problems. They are utilized as a protectant for the unaffected portions of the grass. When favorable conditions are present, the turf should be sprayed in order to keep the fungus from penetrating the grass blades. Repeat applications will be needed for as long as the weather is cool and wet. Check the product label for the correct intervals. Several cultural practices promote large patch infection including over-fertilization, over-irrigation, low mowing height, poor drainage and excess thatch. This spring after the grass has greened-up on its own is a good time to look at these factors and make corrections. Keep a close eye because as soon as the temperatures drop again in the fall, large patch can reappear if the corrections were not complete. For more information: https://edis.ifas.ufl.edu/lh044
The Institute of Food and Agricultural Sciences (IFAS) is an Equal Opportunity Institution authorized to provide research, educational information and other services only to individuals and institutions that function with non-discrimination with respect to race, creed, color, religion, age, disability, sex, sexual orientation, marital status, national origin, political opinions or affiliations. For more information on obtaining other extension publications, contact your county Cooperative Extension service.
A spotted Japanese Persimmon leaf, Image Credit: Matthew Orwat
In gardening, brown or black spotted leaves are most often an indicator of disease problems or growth issues. This causes us to worry and seek answers as to why this is occurring. This is good since the first step in solving a plant growth or disease issue is diagnosis.
During Fall, the presence of brown or black spots on leaves of shade and fruit trees is usually not cause for alarm, as it might be in the spring or summer. Certain shade trees such as Southern Magnolia, Japanese Magnolia, various maple, persimmon and oak in the Red Oak group show substantial brown and black leaf spotting as Fall arrives. This is due to the fact that these leaves have been attacked by fungal pathogens and insects since Spring and resistance to damage has broken down over time. As Fall progresses, these leaves will senesce (purposeful deterioration due to age, such as at end of season) and fall to the ground. Therefore, this ugly spotting is part of natural seasonal leaf decomposition in deciduous trees.
Although Fall leaf spotting may not be something to worry about, oftentimes we run into plant problems that need quick diagnosis. Fortunately, your local Extension Office and the Plant Disease Diagnostic Clinic at NFREC exists for these situations. If you need help with plant problems, feel free to contact your local Extension Agent or Master Gardener Volunteer group and they will figure it out or send it along to the Diagnostic Clinic (small diagnostic fee if using NFREC clinic services).
If you happen to live in or near Washington County, we are launching our Second Mondays Free Plant Clinic. Staffed by knowledgeable and friendly UF / IFAS Master Gardener volunteers and your County Extension Agent, we will be available every second Monday of the month from 10am to 2pm at the Washington County Ag Center, which houses the UF / IFAS Extension Office. We will be located in the Master Gardener Volunteer Library which is just left of the central auditorium double doors. The launch date of this plant clinic is Monday, October 11th. See you then!
Photo by Full Earth Farm.
Yes, that’s right! We made it through the hottest part of the year and we are looking ahead to fall just around the corner! I am excited to be discussing September and what we can do to prepare for fall in the garden. As the nighttime temperatures start to cool down, we are given many more options.
For annual color plantings in September, try Ageratum, Celosia, Zinnias, and Wax Begonia to add fall color to your landscape. Bulbs will also add color, texture, and pattern to a bed. If you have some extra space, a variety of elephant ears could really accent a bed or you could always go with the classic calla, narcissus or zephyr lily. Popular vegetables to plant in North Florida in September are broccoli, carrot, cabbage, and collards. See Vegetable Gardening in Florida This is also the time of year to establish strawberry plants. Some great herbs to get started are Mexican tarragon, mint, rosemary, and basil.
Image Credit: Matthew Orwat UF/IFAS Extension Washington County
There are many things that can be done in your lawn during September. Monitoring your lawn for its health and potential insect pests is important this time of year. Common insects to scout for are fall armyworms, chinch bugs, mole crickets, and sod webworms. The last fertilizer application should be done by the middle to end of September. Make sure you choose a fertilizer with little to no phosphorus unless a soil test shows differently. To maintain a healthy lawn, avoid weed and feed products and only apply herbicides in areas with high infestations of weeds. Weed and feed products are not recommended because the timing of when to fertilize and the timing of the weed killer is not always the same. The best management practice is to use a separate treatment for weeds and when possible spot treat weeds.
If you already have bulbs in your landscape from previous growing seasons, this is the time to divide and replant those that are big. You can also add organic matter to new planting areas. Continue working on your vegetable plants and prepare them for either transplants for a fast start, or plants seeds for more variety. Throughout your landscape, it is important that plants are getting the right amount of water as we go in and out of wet and dry weather this time of year.
October will be here before we know it in just a couple of weeks. Look out for the next article to come. We will be getting into the cooler nights and more options for planting vegetables and herbs!
As homeowners, we do value our trees and no one wants to lose a shade tree especially on the house’s south side in Florida. On a recent site visit, a hickory tree had multiple concerns. Upon closer inspection, the tree had a bacterial infection about 30” off the ground with a smelly, black-brown ooze seeping forth. The leaf canopy was riddled with beetle holes and leaf margins were chewed by caterpillars. When leaves were viewed under the microscope, thrips (insects) and spider mites were found running around. The biggest homeowner cosmetic concern arose from hickory anthracnose (fungus) and upon closer inspection found the leaves to have hickory midge fly galls. The obvious question is should the tree come down? I’ll have you read the whole article before giving you the answer.
Each hickory gall is approximately 3/16″ wide.
Hickory anthracnose or leaf spot as seen in the banner photo is caused by a fungal infection during the wet summer months in Florida. The homeowner can usually recognize the disease by the large reddish brown spots on the upper leaf surface (sending a sample to the NFREC Plant Pathology Lab will confirm the diagnosis) and brownish spots with no formal shape on the bottom. Be sure to rake and remove all leaves to prevent your disease from overwintering close to the tree thus reducing infection next year.
A hickory gall has been cut in half to show the leaf tissue.
The fungus can be lessened by good cultural practices and appropriate fungicidal applications. Please remember it is best left to professionals when spraying a large tree. This alone is not cause to remove your tree.
Hickory gall is caused by the hickory midge fly, an insect that lays eggs in the leaf tissue. The plant responds by building up tissue around each egg almost like the oyster when forming a pearl.
As the gall tissue grows, eggs hatch and larva start to feed on this tissue. The larva will continue to
The larva has eaten all soft material inside the gall and is ready to pupate.
feed until it is ready to pupate within the gall. After forming a pupa, the midge fly will eventually emerge as an adult and females will continue to lay eggs on other leaves. The galls are more of a cosmetic damage and because your hickory leaves will fall from the tree as winter comes, the galls will normally not cause enough damage to worry about each year. Once again good cultural practices and disposal of each year’s leaves will reduce the gall numbers next year.
In a large tree with many leaves, foliar feeding by beetles and caterpillars do cause damage though the leaves will still produce enough food (photosynthesis) to keep the tree alive. Most of us never climb our trees to look at leaves to see the small insects/mites and there are more than enough leaves to maintain tree health.
The biggest concern during my site visit was their tree’s bacterial infection. A knife blade was pushed into the wound area and went in less than 1/4″. The homeowner was instructed to look at bactericide applications. In the end, this hickory tree with so many problems is still shading the home and helping cool the house. It is still giving refuge to wildlife and beneficial insects. When in doubt give our trees the benefit and keep them in place. Remember your local Extension agent is set up to make site visits and saving a tree is time well spent.
On August 12, 2021, our panel answered questions on a wide variety of landscape topics. Maybe you are asking the same questions, so read on!
Ideas on choosing plants
What are some perennials that can be planted this late in the summer but will still bloom through the cooler months into fall?
Duranta erecta ‘Sapphire Showers’ or ‘Gold Mound’, firespike, Senna bicapsularis, shrimp plant, lion’s ear
Where can native plants be obtained?
Dune sunflower, Helianthus debilis. Photo credit: Mary Salinas UF/IFAS Extension.
Gardening Solutions: Florida Native Plants – see link to FANN: https://gardeningsolutions.ifas.ufl.edu/plants/ornamentals/native-plants.html
What are some evergreen groundcover options for our area?
Mondo grass, Japanese plum yew, shore juniper, ajuga, ferns such as autumn fern.
What are some ideas for partial morning sun butterfly attracting tall flowers to plant now?
Milkweed, salt and pepper plant, swamp sunflower, dune sunflower, ironweed, porterweed, and salt bush.
I’m interested in moving away from a monoculture lawn. What are some suggestions for alternatives?
Perennial peanut, powderpuff mimosa, and frogfruit.
We are new to Florida and have questions about everything in our landscape.
Florida-Friendly-Landscaping TM Program and FFL Web Apps: https://ffl.ifas.ufl.edu/
UF IFAS Gardening Solutions: https://gardeningsolutions.ifas.ufl.edu/
What are some of the top trends in landscaping today?
Houseplants, edible gardens, native plants, food forests, attracting wildlife, container gardening, and zoysiagrass lawns
Artwork broccoli is a variety that produces small heads. Photo credit: Mary Salinas UF/IFAS Extension.
What vegetables are suitable for fall/winter gardening?
Cool Season Vegetables: https://gardeningsolutions.ifas.ufl.edu/plants/edibles/vegetables/cool-season-vegetables.html
North Florida Gardening Calendar: https://edis.ifas.ufl.edu/publication/EP451%20%20%20
Florida Vegetable Gardening Guide: https://edis.ifas.ufl.edu/publication/vh021
How can I add herbs to my landscape?
Herbs in the Florida Garden: https://gardeningsolutions.ifas.ufl.edu/plants/edibles/vegetables/herbs.html
My figs are green and hard. When do they ripen?
Why Won’t My Figs Ripen: https://www.lsuagcenter.com/profiles/rbogren/articles/page1597952870939
What is best soil for raised bed vegetable gardens?
Gardening in Raised Beds: https://edis.ifas.ufl.edu/publication/EP472
And there are always questions about weeds
How can I eradicate cogongrass?
Chamber bitter is a troublesome warm season weed in our region. Photo credit: Brantlee Spakes Richter, University of Florida, Bugwood.org
Is it okay to use cardboard for weed control?
The Cardboard Controversy: https://gardenprofessors.com/the-cardboard-controversy/
What is the best way to control weeds in grass and landscape beds?
Weed Management Guide for Florida Lawns: https://edis.ifas.ufl.edu/publication/EP141
Improving Weed Control in Landscape Planting Beds: https://edis.ifas.ufl.edu/pdf/EP/EP52300.pdf
Can ground water be brackish and stunt plants?
Reclaimed Water Use in the Landscape: https://edis.ifas.ufl.edu/publication/ss545
How can I prevent erosion from rainwater runoff?
Stormwater Runoff Control – NRCS: https://www.nrcs.usda.gov/wps/portal/nrcs/detail/national/water/?cid=nrcs144p2_027171
Rain Gardens: https://gardeningsolutions.ifas.ufl.edu/design/types-of-gardens/rain-gardens.html
What is the best time of the year to propagate flowering trees in zone 8B?
Landscape Plant Propagation Information Page – UF/IFAS Env. Hort: https://hort.ifas.ufl.edu/database/lppi/
Which type of mulch works best on slopes greater than 3 percent?
Landscape Mulches: How Quickly do they Settle?: https://edis.ifas.ufl.edu/publication/FR052
When should bulbs be fertilized?
Bulbs and More – UI Extension: https://web.extension.illinois.edu/bulbs/planting.cfm
Should I cut the spent blooms of agapanthus?
Agapanthus, extending the bloom time: https://gardeningsolutions.ifas.ufl.edu/plants/ornamentals/agapanthus.html
Monarch caterpillar munching on our native sandhill milkweed, Asclepias humistrata. Photo credit: Mary Salinas, UF IFAS Extension.
I planted native milkweed and have many monarch caterpillars. Should I protect them or leave them in nature?
It’s best to leave them in place. Featured Creatures: Monarch Butterfly: https://edis.ifas.ufl.edu/pdf/IN/IN780/IN780-Dxyup8sjiv.pdf
How does Vinca (periwinkle) do in direct sun? Will it make it through one of our panhandle summers? Can I plant in late August?
Periwinkles and No more fail with Cora series: https://gardeningsolutions.ifas.ufl.edu/plants/ornamentals/periwinkles.html#:~:text=Plant%20your%20periwinkles%20where%20they,rot%20if%20irrigated%20too%20frequently.
Insect and disease pests
What to do if you get termites in your raised bed?
The Facts About Termites and Mulch: https://edis.ifas.ufl.edu/publication/IN651
How to combat fungus?
Guidelines for ID and Management of Plant Disease Problems: https://edis.ifas.ufl.edu/publication/mg442
Are there preventative measures to prevent diseases when the humidity is very high and it is hot?
Fungi in Your Landscape by Maxine Hunter: http://blogs.ifas.ufl.edu/marionco/2020/01/16/fungi-in-your-landscape/
If you missed an episode, check out our playlist on YouTube https://www.youtube.com/watch?v=bp0HfdEkIQw&list=PLhgoAzWbtRXImdFE8Jdt0jsAOd-XldNCd
The lawn is a source of pride for most and anything out of the ordinary causes alarm. Now image finding something that looks like lumpy green jelly in your turfgrass and it doesn’t go away. You try raking it, spraying it, covering it, and it still comes back time and time again. One of the things we see in late spring/early summer turf is a reemergence of cyanobacteria (Nostoc), sometimes confused with algae because of green coloring and this remains all summer long.
Dehydrated cyanobacteria in a centipedegrass lawn.
Unlike normal bacteria that needs a food source, cyanobacteria contains chlorophyll and produces its own food source through photosynthesis which allows it to grow on bare sandy soils, fabric mats, concrete sidewalks, plastic, and yes even your lawn. Besides the green pigment, it also produces a blue pigment and is why we call it cyanobacteria which means blue-green bacteria. In addition to photosynthesis, cyanobacteria can also fix nitrogen, and are believed to produce cyanotoxins and allelopathic compounds which can affect plant growth around them.
Cyanobacteria are considered one of earth’s oldest organism and they have tremendous survival capabilities. They can dry out completely, be flat, flaky, black-green dried particles in your lawn and once rehydrated, spring back to life. If you happen to notice it spreading throughout your yard, remember that pieces of the organism can stick to your wet shoes or lawnmower tires and be transported unintentionally.
The question then becomes how to control the cyanobacteria and reclaim your turfgrass. The first solution is to have a healthy lawn. Cyanobacteria likes poorly-drained compacted soils. This same condition is unfavorable to turf growth and why you end up with bare spots and establishment. Reduce soil compaction by using a core aerator, and then adding organic matter. This will increase drainage, gas exchange, and encourage microorganism populations which I like to call soil pets. Spike aerators only push the soil particles aside and don’t really loosen as well. Try to reduce low lying areas in the lawn where water sits after rainfall and irrigation. You might have to till and reestablish those areas of the yard.
The same cyanobacteria pictured above 24 hours after being rehydrated in a petri dish of standing water.
Controlling the amount of water Mother Nature gives us and humidity levels during summer is not possible, but you can control your irrigation whether it be automatic (sprinkler system) or hand-watered. During the rainy season, you should be able to get by with only rainfall and shut off your system. If needed during extended dry weeks, it is easy enough to turn the system back on. It is thought that cyanobacteria likes phosphorus which is another reason to use little to no phosphorus in your lawn fertilizers.
As you begin to rid your lawn of cyanobacteria, remember when fully hydrated it forms a slippery surface so be careful walking on it. Cultural practices will be more effective in controlling the spread versus using chemical methods. Cultural solutions are safer for your lawn, yard and all of the wildlife that visits. If you need help with your cyanobacteria, please contact your local Extension office and we are always happy to assist.
A special thanks to Dr. Bryan Unruh, UF/IFAS for his assistance in identifying the cyanobacteria.
For additional information, please read the sources listed below.
Biology and Management of Nostoc (Cyanobacteria) in Nurseries and Greenhouses. H. Dail Laughinghouse IV, David E. Berthold, Chris Marble, and Debalina Saha
Rain, Overwatering Can Cause Slippery Algae to Pop Up in Turfgrass. C. Waltz
Nostoc. N.J. Franklin