Weed management questions

[bigterp]

Planning to follow the triangle approach to weed control and had a few questions. A quick background first. My 20K square foot lawn is, to my best guess, a mix of KBG, TTTF and some rye grass. It's quite the melting pot of grass types, but seems to do very well, minus the numerous weeds that also flourish. I have numerous deciduous trees in both my front and back lawns and my property is bordered by woods. This is my first attempt at caring for my lawn other than mowing. After a soil analysis, I've determined I'll only need to start a fall nitrogen regimen. All other nutrients are in the proper ranges and balances and my pH is at 6.2. Plan for the nitrogen is to use slow release urea starting around Labor Day at the rate of 1lb/K of N per month. Then a quick release urea at the same rate late fall as a winterizer. A few weeks ago I applied BLSC and KH and plan to repeat the application in the next week or two.This past weekend I removed 3 pines and 1 diseased tree from my front lawn and seeded these areas. I also seeded a few spots in the back lawn that were in need. With all of that being said, my questions are:

- With the trees in my lawn should I avoid any herbicide with Dicamba in it and stick with just 2,4D? I've read conflicting information about Dicamba and trees, but would rather error on the side of caution and not risk damaging any of my trees if Dicamba is indeed a risk to trees.

- I plan to start my triangle approach 2 weeks or so after my first urea application. This would be 4 weeks out from the new seedings mentioned above. Should I avoid spraying any herbicide on the newly seeded areas 4 weeks out?

- There are spots in my lawn that are pretty weedy, others are barely weedy or not weedy at all. The heavier weeded areas I'm concerned with the need to overseed/re-seed these areas once the weeds die off. Is it silly to expect the surviving grass to fill in the areas that will now be void of weeds? My issue with overseeding or re-seeding is the chore of irrigation. I do not have any in ground sprinklers and would be relying on hose end sprinklers and hand watering to keep very large areas irrigated. This is already proving to be quite the chore, although manageable, with the seedings I just did over the weekend.

-If after tackling my weeds using the triangle approach and there is a need to seed the bare spots, should this be done in the Spring? I'm assuming it would be too late in the year to do any seeding after my weeds have died. My first average frost date is Oct. 11-20th. This would only be 4 weeks after my bottom triangle application.

[ken-n-nancy]

Planning to follow the triangle approach to weed control and had a few questions. A quick background first. My 20K square foot lawn is, to my best guess, a mix of KBG, TTTF and some rye grass.

Welcome to the site and thanks for the background info! It helps folks to understand what your situation and objectives are when discussing possibilities of how to proceed.

It's quite the melting pot of grass types, but seems to do very well, minus the numerous weeds that also flourish.... This is my first attempt at caring for my lawn other than mowing. ...

Sounds like you're charting out a good course. Improve your lawn through good care techniques as you describe, and you'll definitely see a positive change this fall!

With the trees in my lawn should I avoid any herbicide with Dicamba in it and stick with just 2,4D? I've read conflicting information about Dicamba and trees, but would rather error on the side of caution and not risk damaging any of my trees if Dicamba is indeed a risk to trees.

Personally, I apply no pesticides with Dicamba for the same reason. I don't know whether or not it really helps the trees, but I've found that 2,4-D for "level one" of the triangle approach works just fine for me. I use a "generic" 2,4-D product from Tractor Supply Co made by PBI Gordon that is called something like "Pasture Pro."

In my opinion, the biggest difference by leaving out Dicamba is that it sometimes takes a little longer for the weeds to shrivel up and die, but if one is patient, it doesn't make a big difference -- lawn care is a marathon, not a sprint, and whether the weed succumbs in 3 days or 10 days doesn't make much of a difference in my book...

I plan to start my triangle approach 2 weeks or so after my first urea application. This would be 4 weeks out from the new seedings mentioned above. Should I avoid spraying any herbicide on the newly seeded areas 4 weeks out?

You don't want to apply 2,4-D to new seedlings. I don't recall exactly what the label recommendations are on 2,4-D for new seedlings, but you will find that information on the label of the specific product you're applying.

Personally, I don't worry much about "easy" weeds that would be handled by 2,4-D in a newly seeded area. They're usually sparse enough and easy enough to identify that the worst offenders can be handled by hand-pulling around the time the newly seeded area is ready for its first mowing. Plus, they'll succumb readily enough to a spraying after the grass is a little more mature. You can then spray the weeds with 2,4-D when the grass has developed sufficiently. (Just off the top of my head, I seem to recall that labels usually recommend to wait until the grass is developed enough for the 2nd or 3rd mowing.)

There are spots in my lawn that are pretty weedy, others are barely weedy or not weedy at all. The heavier weeded areas I'm concerned with the need to overseed/re-seed these areas once the weeds die off. Is it silly to expect the surviving grass to fill in the areas that will now be void of weeds?

Not silly at all. Personally, this fall if I were in your shoes, I'd be inclined to do just the Fall Nitrogen Regimen and the killing of the weeds via the Triangle Approach. When the existing grass transitions from being in survival mode to thriving due to having good care, you'll be surprised at how much even an "average" lawn can improve in just a month or so in the fall. I've never had real good results in overseeding, but I know that plenty of others do.

If after tackling my weeds using the triangle approach and there is a need to seed the bare spots, should this be done in the Spring?

A picture would help a lot to having us understand the situation. In general, in a lawn which has received no care other than weekly mowing, there is a surprising amount of grass growing sparsely in and amongst the weeds. With proper care, in just a single fall or spring season each spindly blade of existing grass will grow into a clump of 30-40 blades and be a few inches across. As long as you have at least one spindly blade of grass in every area the size of a drink coaster, you'll be surprised at the recovery that can take place.

Below are links to a couple "success stories" of the Triangle Approach and Fall Nitrogen Regimen that you may find of interest:

viewtopic.php?f=4&t=16835&p=229709

viewtopic.php?f=4&t=14996

[bigterp]

Thanks for such a thorough response!! That all makes sense, and makes me feel much more comfortable tackling my weed problem. My biggest concern with doing the triangle approach on my lawn was ending up with numerous bare spots (both small and large) after the weeds had died. But it sounds like I might not have much to worry about after all, especially if my grass responds well to my fall nitrogen regimen and the decrease weed competition.

I found the Pasture Pro at my local Tractor Supply. Just finished reading the label. What concentration do you use? The label recommends 0.5% to 1% spray application (4tsps/gal to 8tsps/gal). I'll be using a handheld pressure sprayer (2 gallon) to do my entire lawn, so it's going to take a little while but that's OK. Are you just basically wetting everything with the mixture? This also looks like it would work well on the encroaching vegetation (mostly thorny plants/bushes) that creep from the woods into my yard and drive me nuts when I cut the grass.

Plan now is to continue with my nitrogen regimen and do a blanket spraying of the 2,4-D around 2 weeks after my first urea drop. Then assess what I have going into winter. If I really feel the need to fill in any bare spots I might try some dormant seeding late winter or just wait until spring to patch up anything that is needed.

Thanks again. Much appreciated!!