Turf Management-De-thatching, what does it do?

[Carl Rogers]

Another series of questions from the peanut gallery...

What is de-thatching?

Does it help Turf breathe or stimulate growth?

How often is enough?

Would the inablity of through the green short grass areas to dry out a sign it is needed?

In a climate of maintenance reduction, is it a must do activity?

[John Moore II]

OK, for the non-superintendent version.

Another series of questions from the peanut gallery...

What is de-thatching?

Thatch is an accumulation of clipping and dead plant material below the leaves of the plant. It prevents air and water from moving freely in the turf. To de-thatch, typically the green staff will use a verti-cut attachment on a regular greens mower to et down below the surface and break up the thatch.

Does it help Turf breathe or stimulate growth?

Yes, it helps turf breathe.

How often is enough?

At the courses where I used to work, we typically verti-cut the greens once a month, on the months that we did not aerify the greens.

Would the inablity of through the green short grass areas to dry out a sign it is needed?

Not sure, I don't think I've ever seen a course specifically de-thatch fairway grass. We would aerate the fairways once a year, but I don't think we ever verti-cut them.

In a climate of maintenance reduction, is it a must do activity?

Yes it needs to be done. And it doesn't cost any more than normal maintenance. The blade attachments can be purchased and the cost spread over several years. And the actual cutting just takes the place of mowing the greens and surrounds one morning. There is no real additional cost to the process, to the best of my knowledge.

Hope this helps. Maybe Tony Nysse, Joe Hancock or someone else will chime in and give a better answer.

[Don_Mahaffey]

Carl,
I'll bet your super would be able to give you most accurate answers to your qustions.

In general de thatching is a routine part of most fine turf management programs.

Clippings don't usually contribute to a thatch problem unless you already have one.

You de thatch as often as you need to.

Are you talking maintenance reduction or cost reduction? A turf with no thatch issues will be less expensive to care for then a turf that has thatch problems. Some mat is nice, but too much and you inhibit water and air movement and pretty soon your growing turf in thatch instead of soil and that will be a problem. Cutting out thatch management for the sake of saving $$$ is a short term fix and a long term problem. It may save a little now but it will cost more down the road.

[Michael Rossi]

John

Good description, just a couple additions.

Thatch is living roots and shoots not just the dead stuff. It can be thought of as a condo for disease and insects, the thicker the layer the bigger the population possible. The thatch will also slow or prevent water, nutrients and pesticides from getting to the soil. When thatch dries out it can become hydrophobic. If a thatch accumulation is buried by topdressing it can attribute to black layer. Some thatch is desired to help protect the crown of the plant, <1/4" and is usually referred to as a matt layer.

When to remove - when the turf is actively growing.

How often - depends on turf type, time of year and other cultural practices. If an aggressive topdressing program is in place it may never be required, generally verticutting and topdressing go hand in hand.

Verticutting assists in getting nutrients and water to the soil, and does allow the turf to breath as you put it, by allowing the gaseous exchange to occur of CO2 and O2 back and forth from the soil and atmosphere providing the soil is not compacted. V-cutting will also help firm up the surface by removing the puffy thatch.

To save $$$ by skipping a practice or 2 perhaps for a short time, but to eliminate the program will cost more $$$ in the long run. The super on site could be able to give you a hands on view and I would guess welcome your interest.

[Craig Sweet]

We recently finished verti-cutting all our fairways...with a triplex mower no less!  Not only does it do everything already mentioned, but it also makes the fairways look "cleaner" in the Spring!

We verti-cut roughs every spring...tee's at least once a season, and greens at least once a month.

[John Moore II]

We recently finished verti-cutting all our fairways...with a triplex mower no less!  Not only does it do everything already mentioned, but it also makes the fairways look "cleaner" in the Spring!

We verti-cut roughs every spring...tee's at least once a season, and greens at least once a month.

Craig-I just have to ask what club you are associated with? Because I was with a rather mid/high end place and I don't recall us ever verti-cutting the fairways or tees, much less the rough. Must have a major budget around there.

[Michael Rossi]

We recently finished verti-cutting all our fairways...with a triplex mower no less!  Not only does it do everything already mentioned, but it also makes the fairways look "cleaner" in the Spring!

We verti-cut roughs every spring...tee's at least once a season, and greens at least once a month.

Craig-I just have to ask what club you are associated with? Because I was with a rather mid/high end place and I don't recall us ever verti-cutting the fairways or tees, much less the rough. Must have a major budget around there.

John

If you do not verticutt it cost more, who is spending more on maintenance?

EDIT - it should be noted that verticutting is not the only way to control the thatch layer and many other cultural practices can keep it in check. Verticutting is just one tool that accompanies many.

[Michael Rossi]

Carl

It does also stimulate growth.

[Don_Mahaffey]

John,
Removing thatch can be as easy as pulling a spring tooth harrow around the course or as expensive as every other week verticutting with small equipment. Either way if your growing a thatch producing turf then your dealing with it in some way or your paying for it down the line through increased irrigation, fertility and other chemical applications. Chances are the course that doesn't do this basic cultural practice is the one with the higher maintenance costs and budget.

[John Moore II]

I honestly may be mistaken about us verti-cutting the fairways and rough. Maybe I just never noticed it. I would notice it on the greens because you an see the lines in the turf where they cut. But I just never saw that in the fairway or other places.

What other ways can you control thatch?

[Michael Rossi]

Aerifying is a major remover of thatch, constant topdressing to keep it diluted, grooming (nearly verticutting), scarifying, fertility levels, drainage and watering frequency. Also if a turf manager can keep the microbial population active and the environmental conditions participate the microbes will break down the material as it accumulates.

The variables to each situation make it entirely site specific as to how thatch is managed. 

[Craig Sweet]

John...our budget isn't THAT big! After all, this is Montana     This is the first time we have verticut the fairways in the four years I have been here...we have aerified them every year with solid tines....the rough does not take too long with a larger mower....one person cutting and someone picking up behind with a Z Master....as for the greens...we verticut as often as possible, aerify with a hydro injection aerifier every so often, and punch holes twice a year...

[Tim Nugent]

Craig, the type of grass you have will influence the type and amount of cultivation.  You say Montana and that means cool season turf.  But even then, Bent will have different requirements than Bluegrass or Fescue.  Everything above is correct.  Also, keep in mind in warm, moist, shaded areas are perfect breeding grounds for many deseases. 

[Bill_McBride]

Everybody who puts in Champion putting greens loves the surface, but I have heard (from supers) that it is an absolute bear to maintain, heavy dethatching required very soon in its life.

[Pete Lavallee]

The City of San Diego dethatches both Torrey Pines and Balboa Park GC's each year prior to overseeding. The Kikuyu makes a ton of thatch and the City fills several 40 foot dumpsters at each course with the dead brown grass collected. Part of the effort is to send the grass into dormancy to help the overseeding. Of course removing all that dead material must help the turf as well.

[Craig Sweet]

Tim...we have mostly bent and poa....the poa really suffers here in the winter.... as you can imagine...in fact crown hydration (really dehaydration) was real bad this winter.. so we will probably do some serious seeding this spring with bent....both greens and fairways.

[Steve Okula]

Fairway verticutting is fairly common on courses with bermuda grass turf, even on modest budgets.