Guideline for initial fertilizer/pre-em application?

[wrooster]

Gents,

Is there a basic rule-of-thumb in terms of average temperature (specifically soil temperature) for initial springtime application of N and pre-emergent?

Right now in north/central NJ, the soil temperature is a bit lower that normal -- as there has been little sign of spring to date, and in fact it's 28'F outside right now.

Clicking here shows soil temperature to be about 40'F:
http://climate.rutgers.edu/njwxnet/m...erature1&t=cur

So...

a) there isn't much sign of the turfgrass coming out of dormancy. I have TTTF (Johnathan Green Black Beauty Ultra, specifically).
b) waiting for the 2nd cut of the grass this year seems perhaps a bit late for effective pre-emergent application.
c) when, then?
d) would it be beneficial to split application of the N and pre-emergent, rather than using a single integrated product?

Thanks,
Wrooster

[DA Quality Lawn & YS]

First off you are jumping the gun to the extreme thinking you are close to flinging out fert and pre now.
Hold the horses.
Crab begins to germinate at 50 deg. soil temps, and that has to be a consistent temp not just a daytime hi temp.
Around there, that doesn't happen normally until mid May or so. Last year was anomaly. You have to adjust each year. Find a soil temp website online to use, or go according to your own meter.

[wrooster]

Are you perhaps posting from a smartphone?

Originally Posted by DA Quality Lawn & YS

First off you are jumping the gun to the extreme thinking you are close to flinging out fert and pre now. Hold the horses.

Where did I mention above that I was looking to apply anything right now?

Originally Posted by DA Quality Lawn & YS

Crab begins to germinate at 50 deg. soil temps, and that has to be a consistent temp not just a daytime hi temp. Around there, that doesn't happen normally until mid May or so. Last year was anomaly. You have to adjust each year. Find a soil temp website online to use, or go according to your own meter.

Above, in my original post, you may see a link to just such a website.

My question:

Originally Posted by Wrooster

Is there a basic rule-of-thumb in terms of average temperature (specifically soil temperature) for initial springtime application of N and pre-emergent?

Wrooster

[Smallaxe]

After the second mowing would be a fine time for both fert and pre-m... the grass tells you more about how conditions in the soil are than average temp websites...
Depending on your HEAT conditions such as sandy soils with thin grass baking in the sun all day, may very well quickly have CG germinating as soon as the second mowing is finished...
If you have realitively thick grass on fertile soils and partial shading from nearby trees throughout the day ,,, you may not see CG until the mid-Summer period...

There is no One-Size-Fits-All button...

[boss75]

Originally Posted by DA Quality Lawn & YS

First off you are jumping the gun to the extreme thinking you are close to flinging out fert and pre now.
Hold the horses.
Crab begins to germinate at 50 deg. soil temps, and that has to be a consistent temp not just a daytime hi temp.
Around there, that doesn't happen normally until mid May or so. Last year was anomaly. You have to adjust each year. Find a soil temp website online to use, or go according to your own meter.

Hello, do you know of such a web site that that would give me the temp. for SE Mich.

[RigglePLC]

Neither of my soil temp links is working. Maybe they think it is too early to start. You could assume that crabgrass will arise on about the first frost-free date in your area.
http://www.farmersalmanac.com/weathe...e-frost-dates/
Crabgrass is killed by frost of course.

[GreenUtah]

Since the almanac was mentioned, you can also use forsythia as a visual clue in the northern climes. It will generally set its blooms when the soil temperature is approaching germination temps.

As mentioned earlier, turf with south/southwest exposures, surrounded by cement, asphalt, reflected light/heat, thin and dry, etc. etc. will go sooner. If you can locate and visually cue off a forsythia bush in those circumstances, you may not need to soil temp sample each day if that's not your thing.

[Smallaxe]

Originally Posted by GreenUtah

Since the almanac was mentioned, you can also use forsythia as a visual clue in the northern climes. It will generally set its blooms when the soil temperature is approaching germination temps.

As mentioned earlier, turf with south/southwest exposures, surrounded by cement, asphalt, reflected light/heat, thin and dry, etc. etc. will go sooner. If you can locate and visually cue off a forsythia bush in those circumstances, you may not need to soil temp sample each day if that's not your thing.

Forsythia predicts Broadleaf,,, not crabgrass...

[GreenUtah]

Originally Posted by Smallaxe

Forsythia predicts Broadleaf,,, not crabgrass...

http://purdueturftips.blogspot.com/2...germinate.html

[Smallaxe]

Originally Posted by GreenUtah

http://purdueturftips.blogspot.com/2...germinate.html

* " Plant Phenological Indicators: The flowering of landscape plants can also be used as a good estimate of when crabgrass might be germinating. Many are aware that forsythia is traditionally considered a good plant to indicate that crabgrass will soon start germinating. Forsythia will be in full bloom prior to crabgrass germination and forsythia flowers will wither near crabgrass germination (Masin et al., 2005; Cardina et al., 2011). Most think that crabgrass germinates when forsythia blooms, but this is false. Instead, turf managers should use forsythia blooms as an encouragement to hurry up and get their preemergence application made before crabgrass begins to germinate. ..." *

Interesting comments from Purdue... Perhaps it is closer to the truth in the areas that they have tested...
However:

My experience in CentroWisco is that firsythia blooms around the 3rd week in April...
Full Sun well warmed garden soil has its germination flush in the first week in May...
The earliest I've ever seen CG in lawns is sometime in June,,, but it is closer to July when we finally get hot...

I never use pre-m so I get to spot it, if and when it occurs...