Rain in June! LDS Halts, 1st Waitea, Jumping Worms? and Bentgrass is Growing
Well it finally happened. It rained. And so we are now growing better. Some warmth too. And if you wanted a growth barometer, look no further than your garden tomatoes — in a week they’ve seen some good growth. The same is true of creeping bentgrass or Agrostis stolonifera. Poor ‘ole bent has been shaking off the cool, cloudy Chicago blues this all dry spring. Bentgrass is finally growing given a couple things finally happened. 1) Nighttime lows are now above 50 degrees, and 2) precipitation of 0.5 inch or more (drum roll here). Nevertheless, we are still recovering from substantial localized dry spot or LDS. Especially dry conditions hit us hard and hit us early. To summarize the month of May, the national weather service explained it this way: Chicago received 1.35 inches in May which was 3.14 inches below normal. Another way it was explained? “May was VERY DRY”.
Hopefully you’ve been looking down and enjoying the view(s) as you walk outdoors. In the landscape, bearded iris or I. germanica are peaking. This flowering perennial is estimated to have 10,000+ varieties courtesy of professional (and amateur) breeders. Each variety can represent itself within a range of available plant sizes from 8 inches (dwarf) to 3 feet (tall), not to mention flower color (you name it). Some are now saying “Hallelujah” (golf course superintendents). Putting greens are finally looking a uniform green color. What’s next? For growers June represents a critical month during which root growth is maximized — soil temperatures often remain within the optimum range of 50-65 degrees. By midsummer (July-August) things will not be the same. During periods of supraoptimal soil temperatures (>77 degrees) natural root loss and the possibly of physiological decline known as summer bentgrass decline can and will occur. Just realize all hands are on deck right now to keep it (deep roots) that way — “an ounce of prevention is worth a pound of cure.” So get out, swing your club and enjoy — “practice makes perfect.”
Weather
Scouting for Disease — Waitea Patch or Brown Ring Patch (Waitea circinata var. circinata)
Following a period of extended rainfall on June 4, our first outbreak of fungal disease was observed on Sunshine Course in Lemont, Illinois. It wasn’t anything to write home about — treatment not required. The symptoms + turfgrass host + time of year = most likely Waitea patch or brown ring patch. Appreciate the exchange of notes with Rutger’s University (Dr. Ming-Yi Chou here).
Symptoms and Signs
- On Poa annua, rings will appear bright yellow
- On creeping bentgrass, rings can appear orange-bronze
- What we observed (relatively strong symptoms) appeared on newer creeping bentgrass varieties of ‘Pure Eclipse’, ‘Pure Select’ and ‘Piranha’
- Incubation overnight = produces lots of white-gray mycelia and is helpful for identification
- Hyphae = typical Rhizoctonia characteristics, relatively large with right angle branching and is helpful for identification
Conditions
- Soil temperatures 50–60 degrees F and air temperatures 65–85 degrees F
Cultural Control
- Promote creeping bentgrass growth over Poa annua
- Liquid spoon-feeding nitrogen (urea) has been shown to lessen Waitea
- Time irrigation in the early morning hours — do not water in the evening hours because natural leaf wetness may be extended (increases disease).
Chemical Control
- Many good systemic fungicides are available that control Waitea.
- Lightly watering-in immediately after fungicide application is often suggested because Waitea is active in the thatch/crowns of turfgrass.
- Contact fungicides do not work well (e.g., chlorothalonil).
Helpful References
Turfgrass Diseases: Brown Ring Patch (Causal Fungus: Waitea circinata var. circinata), PennState Fact Sheet on Waitea, Peter Landschoot, PhD
Chemical Control of Turfgrass Diseases 2024, Bruck Clarke, PhD; Paul Vincelli, PhD; Paul Koch, PhD; Ming-Yi Chou, PhD
Scouting for New Pests — Jumping Worm (Amynthas spp.)
Sometimes you don’t know what it is. And that was our experience when trying to determine what was going on in a local Chicago home lawn in May. It was Kentucky bluegrass lawn mixture that was being damaged by holes. But from what? And so who did I call? Dr. John Schepis, Extension Entomologist, University of Illinois.
Email Thread
May 9, 2025: “Hi John, Fast moving from a video. Creating a lot of holes in a lawn near Waukegan area (far north Chi suburbs). Not sure what it is. Any thoughts? Derek”
May 9, 2025: “Hi Derek, Thanks for sending me this interesting find! I can’t tell anything from the picture, unfortunately, but I think I know what you got from the description. Hope this helps solve the mystery! Best, John”
Asian Jumping Worm Tutorial, John Schepis, PhD
This sounds like the invasive Asian jumping worm (also called crazy worm, or snake worm due to the way they move). When poked, they move absolutely crazy in an attempt to get away, and they generally are known to move faster than our native earthworms. The location seems correct for where it is in Illinois currently, and the holes in the top of the soil make sense, as well as these worms only like to live in the first 2–3 inches of the soil. A big issue with these guys is that they don’t go deep into the soil, so they don’t incorporate nutrients from the surface into the soil, leading to those nutrients being removed as runoff. This poses a particular issue for forests and garden beds, but supposedly are less of a problem for turf (I don’t fully believe this). They also proliferate like crazy, and I believe they can outcompete native worms. I have a friend who specializes in these guys, so I will bother her for you to try to get you some treatment options.
Control Lacking
- Currently we have no treatment options available.
- Prevention of Amynthas spp. is the best method for reducing their spread.
- Do not buy or use jumping worms in gardens, vermicomposting, or bait.
- Avoid introduction of soil from areas in Illinois that are confirmed to have Asian jumping worm.
Helpful References for Illinois
Education & Communication by CDGA’s Green Committee
3 tips to avoid turf stress with cart traffic — from article
- Please practice the daily policy at your course. Cart traffic policies vary from course-to-course and even day-to-day. Slowly growing turfgrass is more vulnerable to heavy cart traffic.
- Avoid traffic over dry or heat-stressed turf. Cart traffic during hot, dry weather should be carefully monitored, as it can cause severe damage. The resultant tire marks often take weeks to heal during the summer.
- Do your best to steer clear of high-traffic areas. Sometimes it’s best to take the road less traveled. Most cart damage appears in areas where traffic is concentrated, like the ends of cart paths.
More information
Wienecke, David L. Letting the Numbers Tell the Story on Cart Damage. Greens Section Record, Nov-Dec 2004.
Final Photo
“Iris pseudacorus, the yellow flag, yellow iris, or water flag, is a species of flowering plant in the family Iridaceae. It is native to Europe, western Asia and northwest Africa. I. pseudacorus grows best in very wet conditions, and is common in wetlands, where it tolerates submersion, low pH, and anoxic soils. The plant spreads quickly, by both rhizome and water-dispersed seed. While it is primarily an aquatic or marginal plant, the rhizomes can survive prolonged dry conditions.
Large I. pseudacorus stands in western Scotland form a very important feeding and breeding habitat for the endangered corncrake. I. pseudacorus is one of two iris species native to the United Kingdom, the other being Iris foetidissima (stinking iris).” see Wikipedia
