Controlling Earthworm Casts

Earthworm casts can be a big nuisance this time of year.  These worm casts have negative effects on the playability and the overall aesthetics of the turf.  They also affect the quality of cut if not removed directly ahead of the mowers.  The earthworms are active all season long, but the casts they leave behind are more noticeable in the fall for a couple of reasons.  First off, it seems as though the soft moist soil this time of year is ideal for them to tunnel in and out of, compared to the hard compacted soils of summer.  More tunnels = more casts on the surface.  Second, our mowing frequency is reduced this time of year due to slower growth rates and reduced staffing levels.  Less mowing = more casts on the surface.

earthworm casts affect ball roll, aesthetics and mowing quality

Interestingly though, there are other forces at work that seem to be contributing to the excessive worm casts.  A recent USGA Green Section Record publication has shed some light on this issue and here is a quote from that article:

"During the past 20 years, however, the problem of excessive earthworm castings interfering with play on golf courses has become more serious and widespread.  Why?  Residues of old, highly persistent chemicals like chlordane, banned many years, are finally dissipating from soils and no longer suppressing earthworms.  Earthworm-toxic soil insecticides, like diazinon, bendiocarb, and carbaryl, have been replaced by chemistries that are more selective."

We have recently completed a trial using an organic fertilizer to control earthworms.  This fertilizer named Early Bird (I know, brilliant marketing) has provided us with excellent control of the earthworms resulting in an extremely significant reduction in worm casts.  We are going to be treating all the tees this week and will continue to monitor the earthworm activity to see exactly how long we can achieve results with each application.  Early Bird also provides nutrition to the turf while controlling the earthworms.

For further information, you can read the USGA Green Section Article in its entirety here: Controlling Earthworm Casts on Golf Courses

A breath of fresh air!

If you play golf on this beautiful October day, one thing you will likely notice is a bit of an unpleasant odour coming from the ground!  Don't worry though, that's a good thing!  It's just our fairways and greens taking a deep breath and exhaling.  FarmTek is on-site today deep-tining the fairways and we are verti-cutting and needle-tining (venting) the greens.  As I explained in an earlier blog post, the late-August deep-tining was cut from the budget and we did not anticipate the impact it would have on our drainage capability.  That being said, it became clear that the fairways were REALLY missing the scheduled deep-tining and became quite saturated as a result.  Here are some photos of today's deep-tining:

Deep-tining underway as the sun rises this morning.

NOT something you'd want to be run over by!

FarmTek guys doing their thing and are they ever good at it!

3/4" diameter channels for air and water movement.

Irrigation flag used to check aeration depth.

8" deep channels will certainly help the fairways drain!  Ahhh!

#1 completed - the holes will disappear with traffic and growth.

Now, onto what's being completed on the greens today.  First, the greens are being verti-cut to help remove organic matter (thatch) by thinning out the turf canopy.  Verti-cutting is a method of mowing with a set of vertically mounted blades that cut into and perpendicular to the surface of the turf.  Here is what a verti-cutting reel looks like closeup:

Series of thatch removing vertically mounted blades.

This slicing action removes organic material at a depth that can be adjusted based on how aggressive you'd like to get.  We are verti-cutting the greens and collars at a depth of 1/16" today, which may not sound that aggressive, but as you'll see we are removing alot of material.  Here is a photo of the verti-cutting triplex in action:

So much thatch removed that it doesn't all make it into the buckets!

Thatch harvested from only 4 greens!

Following the verti-cutting, we needle-tined (vented) the greens.  This venting process is a form of aeration that we can do throughout the year with no disruption to play.  As you'll see the effects of the venting are hardly noticeable at the surface, but the benefits below ground are substantial.  It is NOT a form of removing thatch though, so don't think that this means we can move away from traditional core aeration!  It's benefits are short-term and therefore the process must be scheduled routinely to reap the rewards.  Here are some photos of this process:

5" needle tine.

Needle-tining #5 green following verti-cutting.

Characteristic lines from verti-cutting and holes from venting.

Lastly, the greens were double rolled following the verti-cutting and venting and as you can see below, you can hardly tell we were there:

All that beneficial work done without any adverse effects on ball roll.

***Please note that these tasks could not have been completed as efficiently and effectively without our scheduled Maintenance Morning***