Not late. It will protect from poa a germination now (til hard freeze) and in early spring.

 

PRODIAMINE_65WDG_Label.pdf (domyown.com)

(To add to what G-Man said)

 

I often try to keep a pre-M barrier up on areas of concern into or even possibly through December. After that, I doubt much would germinate or survive in my area, until March.

This reminds me, I need to see if I put down enough last month. I may need to top it off.

 

Came here to post a similar question but don’t want to make a duplicative thread. I’m in NJ and a little behind Aaron in my timing. I overseeded in two stages with my latest germination not coming until the end of September.

If I stick to 60 days post-germination, I’d be right around the beginning of December - is it even worth applying at that point? I want to do something to help with the Poa-A I get in the spring but had to overseed this year because my lawn took a beating from the heat/drought.

 

If you aren't frozen right now an application of prodiamine would be better then nothing. Poa already germinated will if course thrive until summer. But there is nothing you can do.

 

@Green @g-man

This is a timely thread for me, too. I'm working on controlling poa annua and creeping bentgrass in KBG. I planned on a two-part split app of prodiamine (50% in August and 50% in late October), but I goofed and put down 87% of the max annual amount in August.

I applied Anderson's Prodiamine ON DG Pro (0.48%) at 4.1 lb/M SF on August 27. That's 87% of the max recommended 4.7 lb/M SF for KBG. I misread the label and thought I could go to 7.1 lb/M SF on KBG, but that is only for warm season grasses and tall fescue. After I applied it, I re-read the label and found the max for KBG is 4.7 lb, not 7.1 lb (dumb beginner mistake).

Here's my question. Should I try to put down Part 2 of a split app? I'm worried that there's no way I can accurately apply another 0.6 lb/M SF. Or should I wait until spring for the next PRE app?

 

@Idaho Turf

If you plan to apply a low rate of additional Prodiamine, you'll need a formulation that can be sprayed. And everything will need fo be converted to lb AI per acre to determine how much additional from a different form you would need.

You can use the tables included in many Prodiamine products to determine this. Again, some converting will often be needed in many cases, because % AI differs from product to product.

In any case, 4 lbs of 0.48% should last a while. You should figure out how long. I know 3lbs of 0.37% is supposed to last like 4 months. Again, there should be a table or chart.

 

@Idaho Turf
You can use the tables included in many Prodiamine products to determine this. Again, some converting will often be needed in many cases, because % AI differs from product to product.

I bought some liquid prodiamine and can use that for the weak app. I forgot about that approach. Thanks.

The table and instructions included with Barricade 0.48% prodiamine are not self-consistent. The instructions for KBG say "4.7 lb/M SF per calendar year" but the table doesn't go above 3.5 lb/M SF for overseeding (below). It says that 3.5 provides 6 months of protection and has a hyphen for rates above that (I drew the red line for the 4.1 lb/M SF I applied). So what happens between 3.5 and 4.7 pounds? Infinite protection? Permanently sterilized soil? Andersons didn't test here, has no data, and don't know what will happen?

Here's a weird thing. I pre-germinated 4 pounds of KBG at the end of Sept for a 1,100 SF test area. I raked out the dead or damaged creeping bentgrass and poa annua, put down a 1/2 inch layer of compost/soil/sand mix, one app of gly, seeded with Milorganite and HumiChar on Oct 5, and a 1/4 inch top layer of peat moss. I actually have pretty good germination rates and seedlings!

I've got two theories: 1) the seed, being pre-germinated, was not affected by the prodiamine or 2) the prodiamine app is underneath the 1/2 inch compost/soil layer where the seed went. Or maybe both #1 and #2. Anyway, it's an interesting experiment.

My big problem will be cold - we haven't had a frost yet (very late this year), but nighttime temps will be in the 20s in the next three or four weeks. The seedlings will be close to 40 to 45 days old. I'll know next spring if they made it. I'll probably need additional seed then.