[ryeguy]

Is there a reason to prefer something like preen or snapshot over dithiopyr or prodiamine for a pre-emergent in landscape beds? I get that preen and snapshot aren't labeled for lawn use, but what makes them necessary instead of just using your lawn pre-em in your beds too? Is it because the other two depend on soil contact which is harder if there's mulch, rocks, etc?

 

[Colonel K0rn]

Great question, because I was wondering why I should pay $100 for Snapshot at Site One. I'm wondering if it's the longer coverage length?

 

[Pete1313]

No experience with snapshot but I tank mix isoxaben(one of the ingredients in snapshot) and prodiamine and then spray in my beds and had good results. Prodiamine will control the grassy weeds and isoxaben is for better broadleaf control.

 

[Pete1313]

A 1lb bottle of isoxaben will treat up to an acre. https://www.domyown.com/gallery-75-df-specialty-herbicide-p-1499.html
If you have alot of much beds, I think it's worth it. I have 8k sq ft of beds, so 1 bottle will last me about 5yrs.

 

[ryeguy]

Ok, I did more research and I think I found the answer. Pete's post above about isoxaben giving better broadleaf control tipped me off. Incoming info dump.

I read the labels of prodiamine, gallery df (isoxaben), and snapshot. Prodiamine is mostly only labelled to control grassy weeds. On the other hand, snapshot/preen have a mile long list of broadleaf weeds they control.

Pete linked isoxaben above. This is only one of two ingredients in snapshot. I like that it's sprayable, but it doesn't seem that Trifluralin is also available in liquid form, so if you went a spray-only route you're missing out on some coverage you'd get by using the granular.

So, the answer is: snapshot and preen control a significantly wider range of weeds with the tradeoff of not being labeled for turfgrass. You can use prodiamine or dithiopyr for convenience of not having to buy a separate product, but it won't control as many weed types.

Also of note is regular preen is just Trifluralin and claims 3 months of control. Preen Extended Control, which is the same as snapshot but more expensive per sqft app, adds isoxaben to the mix and claims 6 months of control.