Is it ever too late for Serrenade....

[northeastlawn]

My new reno has done OK so far, but last weeks warm and humid weather triggered some fungus outbreaks here and there. I kept the watering to every other day in case it was heat stress related, and applied some Serrenade. I have one more app left in the bottle I have.

We have a good 1" of rain on the way tonight, then a return to cold nights. I'm down to my last bottle of Serenade. Is it worth keeping up the Serene apps as we approach the first frost?

Trying to figure out if its worth picking up another bottle, I realize serenade is made of living things and not sure if they will store well through the winter.

[andy10917]

Generally, I spin down the Proactive Biofungicide Program by October 1st, but if you're still seeing fungal disease in your area (other than Rust), there is no harm in continuing. It will work but slow down until the grass growth stops.

[Green]

Andy...what about applying in early Winter to prevent snow mold? Is that something you recommend or had success with?

[andy10917]

It's not a chemical (it's bacterial), and it is primarily a contact biofungicide. As that, I would expect its action to be very limited if at all. I haven't even looked to see if it lists Snow Mold as a covered disease.

[ken-n-nancy]

It's not a chemical (it's bacterial), and it is primarily a contact biofungicide. As that, I would expect its action to be very limited if at all. I haven't even looked to see if it lists Snow Mold as a covered disease.

I was hopeful that Serenade (Bacillus subtilis) would be effective against snow mold. Some non-research sites claim it is helpful, but I haven't found any research studies that support that.

For our Northeastern US area, the referenced table from Cornell does not indicate effectiveness for Bacillus subtilis on either Gray Snow Mold or Pink Snow mold. There are plenty of chemical fungicides which are listed as being effective against both, however.

[Green]

I was hopeful that Serenade (Bacillus subtilis) would be effective against snow mold.

So, what are you planning to do since you know the evidence isn't strong?

[ken-n-nancy]

So, what are you planning to do since you know the evidence isn't strong?

I'll be cutting the grass shorter after top-growth stops to reduce the length of the blades that will be matted down under the snow and fostering an environment for snow mold. My normal mowing height is 3.75" for the summer. I've brought that down to 3.25" already. I am thinking of leaving it there until growth stoppage, but then cutting down lower (2.75" or even 2.25"?) after that.

Personally, I will not be making continued "N" applications into the "Pause." In recent years, I've continued "N" applications a couple weeks after average first frost. I'm not going to do so this year -- I think the marginal added benefit of additional "N" applications doesn't match the increased risk of having lush grass going into winter.

I'm still on the fence about whether or not to make the final "N" application after top-growth ceases.

[Green]

I'll be cutting the grass shorter...

Same here. I was at 3.75 inches everywhere, and am in the process of taking it down to 3.25". Still have some areas that have yet to be taken down to 3.25. Last year, I did the final mow at 2.75" in most areas, instead of 2.25 like the year before. (I think we have similar cheap Craftsman mowers, which is why our mowing heights are exactly the same.) The reason for not going to 2.25 in most areas last year, was because 2.25 scalped some areas, and I noticed a general decrease in lawn quality as well, probably due to lack of leaf material in some areas.

So, it sounds like you're not going to try a late Serenade app? I'm on the fence about that...Andy makes a good point about it being primarily foliar...you'd think it would just wash right off and into the soil with a rain or snow in December. There's just not enough information about its impact on snow mold, in any case.

Why, may I ask, are you on the fence about the final Winterizer Nitrogen app?
Personally, I had pretty good results last year using various fractions of the 1 lb/K standard...so it doesn't have to be all-or-nothing, either! I did 0.5 lb/K in some areas, 2/3-lb in others, and close to 1 lb in some. The results were very similar in terms of green-up and Spring turf quality. The areas that received 2/3 and almost 1 lb of N might have grown a bit faster than those that received the half pound...but it's all subjective observation.

[Green]

NE lawn: I'm probably going to do one Serenade app on the overseeded areas this week. I haven't done any on those areas yet. Like you, I have part of my last bottle of Serenade remaining. I kept up with some areas regularly during the Summer, and other areas I didn't. One of those areas ended up with a rust outbreak. The Brown patch, rust, dollar spot, leaf spot, etc. were pretty minimal in other areas...definitely better than in years I hadn't used Serenade. I did have some red thread issues in early to mid Summer, though.

[ken-n-nancy]

So, it sounds like you're not going to try a late Serenade app? I'm on the fence about that...Andy makes a good point about it being primarily foliar...you'd think it would just wash right off and into the soil with a rain or snow in December. There's just not enough information about its impact on snow mold, in any case.

I can't imagine a late-fall (after top growth stops) Serenade application would cause any harm, so there's really no reason not to try it, other than saving a bit of $.

Why, may I ask, are you on the fence about the final Winterizer Nitrogen app?

My concern is simply that I've had snow mold and/or winterkill issues the last three years, which are also when I've been making the "after top growth stops" urea application. However, I've also possibly been pushing the "pre-pause" application later than I should, too, so maybe that's the real culprit.

[Green]

I agree about the Serenade idea. If someone has it leftover at the end of the season, why not use it, right?

My concern is simply that I've had snow mold and/or winterkill issues the last three years, which are also when I've been making the "after top growth stops" urea application. However, I've also possibly been pushing the "pre-pause" application later than I should, too, so maybe that's the real culprit.

Do you have any experience with skipping the final winterizer application on a section of lawn? If so, how did that turn out for the section of grass (as far as snow mold and Spring performance)? And was that in a year when you pushed N after the pause?

Speaking of pushing N later in the season...I still need to do a lot more reading and experimenting before I'll be even close to an expert, but I have an idea to try very low concentration foliar Nitrogen for that purpose...on the order of 0.05 lb/K or less. I keep thinking about this because my average first frost date has consistently been at least 6-8 weeks before growth stops in most lawn areas. Andy has told me I shouldn't require 6-8 weeks; 3-4 is sufficient. So I was thinking of a safer way to get that last app or two down. I'm not suggesting that anyone try it, though. Homemade FAS, for example, only incorporates a tiny amount...about 4/100 of a pound of N...if I calculated correctly.

[Green]

One of those areas ended up with a rust outbreak.

Quoting myself just to be clear...that rust outbreak was on a non-Serenade-treated lawn area.

[ken-n-nancy]

Do you have any experience with skipping the final winterizer application on a section of lawn?

No. Well, at least not since I've been taking care of the lawn. (We skipped all attention to the lawn other than mowing for about ten years. I don't think we had any snow mold issues back then, but don't really know for sure, as we weren't paying detailed attention back then...)

If so, how did that turn out for the section of grass (as far as snow mold and Spring performance)? And was that in a year when you pushed N after the pause?

Both good questions, but we haven't conducted those experiments to really know.

The right way to do this would be to set up a semi-scientific study where one treated specific marked-out areas differently to compare the results, while also including a "control" group with no special treatments at all.