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BostonBull
08-18-2008, 08:44 PM
How much is the optimal thickness? How "packed" should it be?

I just took the BR600 to the lawn, and noticed a LOT of very hardpacked areas with 2" of thatch. The grass was growing around these areas and masking them where no grass was growing because of the thatch.

Should I have my lawn de-thatched and start mulching from scratch next spring, or just blow these spots loose, aerate, seed, and go from there?

Sorry if this is a basic question!

Kiril
08-19-2008, 02:17 AM
How much is the optimal thickness?

None

How did you determine your thatch layer?

JDUtah
08-19-2008, 02:31 AM
http://www.lawnsite.com/showpost.php?p=2472741&postcount=50

Maybe?

BostonBull
08-19-2008, 06:28 AM
I was under the impression that thatch was useful at keeping the soil cool, and acting as a mulch in the sense of retaining water, to a certain degree?

Smallaxe
08-19-2008, 07:43 AM
There are 2 separate ideas/definitions of thatch. One is the accepted definition in that it is: dead roots that have grown to the surface and stems.

The other idea is that it is a collection of grass clipping and such that accumulates over time.

Densly packed dead roots and stems become a barrier to water penetration, (necessitating aeration, verticutting, or something) whereas a collection grass clippings do hold and release water into the soil.

Put on a bunch of sugar/molasses and toss on a few bags of compost if you can find it in the local Walmart Garden Center.

treegal1
08-19-2008, 07:04 PM
There are 2 separate ideas/definitions of thatch. One is the accepted definition in that it is: dead roots that have grown to the surface and stems.

The other idea is that it is a collection of grass clipping and such that accumulates over time.

Densly packed dead roots and stems become a barrier to water penetration, (necessitating aeration, verticutting, or something) whereas a collection grass clippings do hold and release water into the soil.

Put on a bunch of sugar/molasses and toss on a few bags of compost if you can find it in the local Walmart Garden Center.I was going to say something long, you did it in a few words, thanks:cool2:, got to go wind just picked up again..............

cudaclan
08-19-2008, 10:22 PM
Two inches of thatch is too excessive for an immediate response to recovery. Certain grass species (Kentucky Blue) are notorious for excessive thatch accumulation. A high concentration of nitrogen fed and shallow watering contribute to rhizome and stolon surface formation. Thatch does not “blanket” or retain water. It does however harbor pests and disease. Proper cutting height, improved grass species, minimal fertilization (if any), core aeration… incorporated minimize thatch. If you choose to dethatch, you will notice numerous bare spots that were not present. This is from the rhizome/stolons on the surface. Poor lawn maintenance practices created these superficial areas.

Whitey4
08-19-2008, 11:08 PM
Aerate the heck put of it, and slit seed.

In MA, NEVER apply fert in March.... that is when grass grows 60% of it's top growth even if it isn't fertilized in the spring. I bag clippings in the spring because THAT excessive top growth can cause thatch build up... then I mulch in the summer, as the shorter clippings will not increase the thatch layer, but will provide water retention and help reduce summer stress.

Let grass wake up on it's own in the spring... the roots will go deeper in search on N, and don't water it either unless there is a dry spell... the roots will also go deeper in search of moisture. That lawn may not (will not) green up as fast as other over fert'd lawns, but in August, it will look better than those others.

If it's that compacted and thatched, I'd aerate this fall... three passes, one horizontal, and two opposing diagonal passes and then slit seed. Aerate again in march, well before most weeds want to germinate. Hold off on fert until mid April, but a good winterizing fert in early November is a good idea... CGM or compost tea if organic is your preference.

Kiril
08-20-2008, 12:44 AM
the roots will go deeper in search on N, and don't water it either unless there is a dry spell... the roots will also go deeper in search of moisture.

Have you been drinking again?

Smallaxe
08-20-2008, 06:06 AM
Have you been drinking again?

As I understand botany - roots are always growing. The question is: where in the soil profile are the going to grow best?

What would the plant do if, let's say, The surface was allowed to dry out and there was NOT 40-0-0 sitting on top of the ground?

Would the roots near the surface decrease activity and the roots lower in the soil - assuming a higher moisture content - continue growing?

Kiril
08-20-2008, 10:09 AM
That is a likely scenario, assuming there are roots lower in the soil profile.

JDUtah
08-20-2008, 01:07 PM
"If the rhizosphere is poor in nutrients or too dry, root growth is slow. As rhizosphere conditions inprove, root growth increases. If fertilization and irrigation provide abundant nutrients and water, root growth may not keep pace with shoot growth. Plant growth under such conditions becomes carbohydrate-limited, and a relatively small root system meets the nutreint needs of the whole plant (Bloom et al. 1993) Indeed, crops under fertilization and irrigation allocate more resources to the shoot and reproductive structures that to roots, and this shift in allocation patterns often results in higher yields." pg 86 http://www.sinauer.com/detail.php?id=8567

When maintaining landscapes we really don't want excessive shoot growth. But we do want good root growth for drought tolerance. Interesting, and a little persuasive to not use fertilizers like normal. Hmmmmm...

BostonBull
08-20-2008, 09:58 PM
Thanks for all the great info!

Here is my fall plan..........

August:
Spray a heavy dose of PHC BioPack

Mid September
Dethatch my entire lawn
Aerate
Gypsum
Lime
Seed (Penningtons smart seed?)

Once seed starts to grow,
more Biopack
Topdress with compost
OR
Spray Tea

November
Maybe an organic fert......MAYBE.

any comments?

DeepGreenLawn
08-20-2008, 10:21 PM
"If the rhizosphere is poor in nutrients or too dry, root growth is slow. As rhizosphere conditions inprove, root growth increases. If fertilization and irrigation provide abundant nutrients and water, root growth may not keep pace with shoot growth. Plant growth under such conditions becomes carbohydrate-limited, and a relatively small root system meets the nutreint needs of the whole plant (Bloom et al. 1993) Indeed, crops under fertilization and irrigation allocate more resources to the shoot and reproductive structures that to roots, and this shift in allocation patterns often results in higher yields." pg 86 http://www.sinauer.com/detail.php?id=8567

When maintaining landscapes we really don't want excessive shoot growth. But we do want good root growth for drought tolerance. Interesting, and a little persuasive to not use fertilizers like normal. Hmmmmm...

This kind of leads me to the question I was wandering earlier today... I will start a new thread though...

Whitey4
08-20-2008, 11:50 PM
Have you been drinking again?

Not sure if you are joking or taking issue with my comments. Cornell produced research that indicated deeper root growth in the spring will occur if the turf is left slightly underwatered, which is kind of difficult to do in the spring anyway. Same thing for the March fert apps... yes, the turf root system will go deeper in search of N and moisture if it is left a little dry and the first fert app is delayed until mid April.

See JDUtah's post... pretty much what I was saying. Care to clarify (for a guy that hates grass?)

Kiril
08-21-2008, 01:20 AM
See JDUtah's post... pretty much what I was saying.

No it doesn't at all, but I have no stomach for argument with you. Roots will grow when conditions are favorable for growth, not in "search" of water or nutrients.

Ask yourself this.

If I have dry soil to a depth of 10" and a source of water at 14", are the roots (3" deep) going to "search" out the water, or are they simply going to die or go dormant?

Same goes for nutrients .... please review methods of plant nutrient uptake.

FYI, I don't hate grass, I hate irresponsible use and management of grass. Does a family of 3 need 10 acres of turf, I THINK NOT! That is an example of irresponsible use of turf.

lilmarvin4064
08-21-2008, 01:30 AM
I'd say optimum thatch thickness is 1/4" or so; >1/2"-3/4" is becoming a problem.

Whitey4
08-21-2008, 02:02 AM
No it doesn't at all, but I have no stomach for argument with you. Roots will grow when conditions are favorable for growth, not in "search" of water or nutrients.

Ask yourself this.

If I have dry soil to a depth of 10" and a source of water at 14", are the roots (3" deep) going to "search" out the water, or are they simply going to die or go dormant?

Same goes for nutrients .... please review methods of plant nutrient uptake.

FYI, I don't hate grass, I hate irresponsible use and management of grass. Does a family of 3 need 10 acres of turf, I THINK NOT! That is an example of irresponsible use of turf.

Huh? What in the world are you talking about? Did I say that moisture should be contained over a freakin foot deep beneath the turf? :laugh:

OK, lets review... the spring in the NE brings a lot of rainfall. Don't irrigate unless it's been 4 or 5 days since the last significant rainfall. YES, the turf's root system WILL naturally seek water... I never said to dehydrate the soil! And good luck with even trying during the sping!

If anyone has been hittin the keg tonight, I'd say it's you! LOL! in addition... early March apps of fert also discourage better, deeper root growth... and that IS what I said, and confoirmed by JDUtah, and btw, Cornell.

So... I guess you think all the PhD's at Cornell are drinking too, eh? Get off yer high horse, and READ.... geeze... the egos around here are whoppers! :laugh:

JDUtah
08-21-2008, 03:01 AM
lol, Whitey, change one word and things will be pristine...

Change seek or search to thrive.

Kiril's point is that the roots don't "search" for water... but that they thrive where water exists. Managing a soil so the top 1"-2" dries out but deeper then that stays moist will cause the roots already lower than the dry point to continues to grow... thus giving the appearance that the plant is growing deeper roots in 'search' of water.

Managing a soil to do such a thing might be harder than expected because of capillary action and also soil diffusion... or am I mistaken?

Also note that the very section i quoted refers to a study done by Weaver in 1926 that clearly demonstrates that wheat roots grew 40% deeper in irrigated soil over non irrigated soil. Kiril knows irrigation, and soil moisture properties... I would try to read deeper into what he said.

Kiril
08-21-2008, 04:31 AM
JD pretty much covered it. Don't mistake deeper root growth in the spring for roots "searching" ("seeking" ... same diff) out water. It would be more accurately put as roots following water as the soil drys because that is where conditions are more conducive to growth. They are not searching or seeking out water as you have suggested. If the conditions are not right for root growth (ex. lack of sufficient water), roots will not grow. Perhaps you need to review your reference.

FYI, in any irrigated scenario the above is true, and is not limited to spring time. This is the reason why we irrigate infrequently and deep. A better reason for not irrigating in the spring is to use what water is already available, and to avoid displacing higher quality water with lower quality water.

For turf that means turn on your TURF sprinklers in the spring when your grass starts to show signs of water stress.

Whitey4
08-22-2008, 10:24 AM
JD pretty much covered it. Don't mistake deeper root growth in the spring for roots "searching" ("seeking" ... same diff) out water. It would be more accurately put as roots following water as the soil drys because that is where conditions are more conducive to growth. They are not searching or seeking out water as you have suggested. If the conditions are not right for root growth (ex. lack of sufficient water), roots will not grow. Perhaps you need to review your reference.

FYI, in any irrigated scenario the above is true, and is not limited to spring time. This is the reason why we irrigate infrequently and deep. A better reason for not irrigating in the spring is to use what water is already available, and to avoid displacing higher quality water with lower quality water.

For turf that means turn on your TURF sprinklers in the spring when your grass starts to show signs of water stress.

Semantics... often how one who needs to defend a position will respond as a defense. You prefer I say that late N apps in the spring and less irrigation RESULTS in more root growth? Fine... there it is.

Kiril
08-22-2008, 11:56 AM
Semantics... often how one who needs to defend a position will respond as a defense. You prefer I say that late N apps in the spring and less irrigation RESULTS in more root growth? Fine... there it is.

More semantics for you. The moon is the sun because it reflects sunlight.

Whitey4
08-23-2008, 12:31 PM
More semantics for you. The moon is the sun because it reflects sunlight.

Put the bottle down...

Kiril
08-23-2008, 12:46 PM
Get your facts straight and I will.

treegal1
08-23-2008, 12:51 PM
he will have me drinking soon, LOLOL:laugh:

JDUtah
08-23-2008, 12:52 PM
I thought the moon was cheese?

And beer was made for turf appplications?

:confused:

Kiril
08-23-2008, 12:56 PM
I like cheese.

treegal1
08-23-2008, 01:00 PM
mmmmmmmmmmm food must go kill and eat, see ya........

Whitey4
08-23-2008, 03:23 PM
sounds like some of you need a basic primer on fert and irrigation... here ya go,,,,

http://www.ccenassau.org/hort/fact_sheets/c117_lawn_maint_for_li.pdf

treegal1
08-23-2008, 08:27 PM
:laugh::laugh::laugh::laugh::laugh:

Whitey4
08-23-2008, 09:29 PM
:laugh::laugh::laugh::laugh::laugh:

Kiril didn't tell me he had a new pet parrot.... treegal want a cracker? :)

treegal1
08-23-2008, 10:12 PM
yes and some cheese for the crackers. something to go with red wine. maybe if i get drunk I can think like you.........

Whitey4
08-24-2008, 02:49 PM
yes and some cheese for the crackers. something to go with red wine. maybe if i get drunk I can think like you.........

Get yer IQ up over 130... and you CAN! :laugh:

heritage
08-24-2008, 03:27 PM
I like cheese.

This was a funny response.Thank You Kiril....I laughed Throughly :)

Pete

JDUtah
08-24-2008, 06:08 PM
(edit - deleted by me)

To each his own I guess. :drinkup: