Poking Holes into Old Thoughts on Core Aeration

Following “Cultivated Thoughts on Thatch Management” and the results of core verifying our cool season turfgrass fields the week before a stretch of 100 degrees F (38 degrees C), I have spent more time examining the merits of core aeration.  Certainly we as professional managers know the importance of core aeration.  But with time constraints and all the other aeration options available to use today, coring is a bit less used.  After the last few weeks, I am convinced that it is time to buck that trend and get back to the basics of core aeration.

Why do we core aerate?  No- its not just to create overtime for ourselves and our work crews!  Removing the column of soil from the profile makes a direct, open avenue for gas exchange in the soil.  Water is able to infiltrate the profile easier, as well as the removal of thatch/ organic material/ soil that could be undesirable.  Certainly solid tines open columns similarly, but they do so at the expense of compacting the soil around the column.  Now-  do not mis-understand me-  ANY type of aeration/ venting that can be done at ANY time is essential to turfgrass survival,  especially in high traffic field situations.  But pulling cores is the most beneficial of all for gas exchange, thatch removal, and water infiltration into the top of the profile (deep tine aeration is a separate subject for deep water infiltration)

Basic teaching advocates core aeration 2 times a year.  I have spent most of my career buying into that thinking, especially because of the intensity of the process.  By now I am realizing that the benefits from core aeration are sometimes lost in the mess that is created from the aeration process.  By the time the clean up process ends, we find ourselves swearing that we will never do it again.  Last week alone we dulled a set of reels following clean up, then bent 2 reels from debris dropped during the coring and sweeping process.  If I walked into the office this morning and declared we are core aerating again this week, there would be mutiny!

But… outside on the fields… the results are evident from the flush of fresh air into the root zone and proper water infiltration.  Green, strong, healthy turf looks like it was 50 degrees last night- even though we spent the week in extreme heat.

Ironically as I was writing this, my colleague Mr. John Turnour made a similar comments about his aggressive core aeration program at Nationals Park in DC.  He too feels that the results are as dramatic as I do with the flush of air into the root zone bringing an immediate plant response with green, vibrant growth and health.  From a scientific standpoint, I am sure there is more to the response than just the air component- Nutrient availability especially.  I will research this and let you know… I am intrigued to know myself.

In conclusion, the question becomes… how often does it need to be done?  My new goal becomes 1 time a month in the growing season, skipping August unless it catches a cool stretch.  So a total 6-8 times.  That will total a removal of about 40% of the profile (@ 5% per time).  We are at 2 with us to July, so hopefully we can finish at 6.

4 more times-  oh boy- Don’t tell our work crews!!!

Cultivated Thoughts on Thatch Management

The past 10 days have seen an up and down weather pattern in the Mid-Atlantic-  A few cool, crisp days followed with hot, dry then hot, humid days.  Dry conditions have prevailed until today, allowing some aggressive cultivation to take place in conjunction with the wrap up of soccer league season and in preparation for summer club lacrosse season.

On cool season pitches, aeration pass number 6 took place with deep tine aeration at 8″ w/ an aggressive 15 degree kick, followed with pass number 7 w/ 3/4″ coring tines on 2×2 spacing.  With the combination, deep compaction relief took place along with air venting and thatch reduction in the top organic layer… both much needed following the heavy traffic of May and entering the summer stress period.  All aeration techniques will continue, just not as aggressively though into the heat….

Bermudagrass received an aggressive core aeration as well.  With it picking up growth… and starting into camp season next week, this is the last break during the week bermudagrass will see until the last week of August.  Deep tine aeration will follow suit next week in the evenings following camps

In reference to thatch reduction from core aeration, following the 1st sweeping of cores from the field we brushed the fields with a heavy brush to stand the grass plants back upright and fluff up any remaining cores.  Around Europe, brushing was common.. so I wanted to add it to our program immediately.  I assumed that the main benefit would be standing up the grass for better health and mowing.  Well I was right on that part, but the biggest immediate difference was the remaining thatch on the very top of the field that was fluffed up.  It was staggering!!  Piles of thatch were everywhere.  Certainly we expect to bring up some, but had no idea that it would be the amount it was.  Especially in a lighter growing period under growth regulation, following heavy traffic, and when we have mowed very little as we raise the height up a 1/4″ to 1 1/4″  If that amount comes up during light growth, I can only imagine the amount that will arise during aggressive growth.

As mentioned, brushing was a common practice around pitches in Europe, as it is in golf course management.  But in sports field management, its not something that takes place a lot.  After the observations of our 1st experience with it… it will become a weekly practice followed with mowing with baskets for collection.  I immediately am looking into tine harrows for additional fluffing and am sharpening the verticut blades as well…  We think our program is aggressive enough- but yet again we are wrong!






Thank You to Charles Boehm- SoccerPlex Stadium Match #30!

Special thanks as well to Mr. Charles Boehm from Potomac Soccer Wire for the kind words and respect in his article yesterday entitled “Minnick Magic”.  Mr Boehm is an exceptional writer- and I appreciate his ongoing curiosity in sports field management.  I have offered him the opportunity to come and try his hand in some mowing-  I am excited for him to take me up on it!  You can see his article at:


No, it is not a misprint that the DC United v Philadelphia Union last night was match number 30 since a May 12th DC United Women fixture.  A stretch of 29 matches took place in 17 days:  DC United Women, Maryland State Youth Soccer Association Championships, Potomac Soccer Association tournament, Nike “The Chance”, and 2 other US Open Cup Matches.  Those, on top of managing 21 other pitches under heavy traffic, have led to fatigue around the facility- from fields and staff.  Special kudos go to Grounds Manager Ryan Bjorn for leading a full speed assault during the chaos.  New assistant manager Dusty LeVan was thrown into the fire as well in early May.  They are more than excited to have the addition of assistant manager Julie Adamski this week. Reinforcements finally! haha

Amazingly enough, the field isn’t screaming for reinforcements.  At least not loud enough for us to be listening to it!!  The center of the field is a little bit thin, but still is thick enough to be described as a “full stand”.  The areas in front of the benches out towards mid-field are showing the most stress from the repeated warm up of the 60 different teams.  Rotating benches from one side of the pitch to the other helped, but the (60 teams x 18 players =) 1080 players warming up directly in front of their bench during the time caused some slight thinning.  In all reality though, over all the pitch is in great shape.

The lessons we learned and the information we have gathered through the heavy traffic period will help us better prepare for next time-  just as similar periods in the past prepared us for this time. Examples of the lessons used are: The field lines were shifted 6 times to move goal mouths and referee lines, 3 forms of aeration to total 5 aerations anchored survival, topdressing took place 2x, and nitrogen fertilizer was avoided in combination with the use of Primo for growth regulation and bio-stimulants to strengthen cell walls and provide energy to survive a week over 90 degrees.

Aeration was certainly the core piece of the puzzle though.  The more we aerate, the more the field is able to sustain. With that thought, ironically today I was graced with a conversation Mr. Brian Wood from Commercial Turf and Tractor back in my hometown of Chillicothe, MO.  Mr. Wood was instrumental in bringing deep tine aeration from the European market to the USA 25 years ago (congrats to him on the anniversary).  It is mind blowing to think that deep tine aeration was unknown here before 1988 when now it is one of the single most important pieces to our maintenance program for managing high traffic athletic fields and having them survive.  This heavy traffic period reinforces that more than ever!!

Brian has been spreading the word of the value of aeration for those 25 years…  Thank you for the Brian. As far as we have come in field quality in the last 25 years, the sky is the limit for the next 25!!!