Too late for pre emergent in South Central MN?

[Steve Bakken]

I was gonna put it down last week but had to leave town. Is there still time or have i missed my window?

[LunkerCity]

Steve, I'd say you are a little late. Here in Ely we have broadleaf weeds popping all over and have had a few dandelions already flower. You may get some control out of it, but whatever is already up will not be affected. Good Luck!

[Steve Bakken]

I'm still trying to figure out how all that works, cuz we've had dandelions here too since the morning ground temps were still in the forties. Do different seeds germinate at different temperatures?

[hotrod1]

It may be to late to get 100% control of crabgrass but if you apply it now you will control any that hasn't germinated yet. If you use a product with Dimension, you can get some control over young crabgrass.

Your pre-emergent will not control dandilions. You will need to use a poest-emergant herbicide for broadleaf weeds

[Dotch]

Unlikely given the GDU accumulation here in SC MN we have seen a lot of crabgrass germination just yet so there is as hotrod says likely still some time. Used to be the rule of thumb was about when the lilacs bloom coincided with time to apply pre-emergent chemical for crabgrass. That's about where we are presently. This roughly corresponds to what the fact sheet from Extension says about crabgrass control.

For broadleaf weeds would definitely agree, post-emerge is the way to go. Dandelions are perennials Steve and they are a cool season weed capable of getting going when temps are still cool. This is why we often see them get going and flower on the south side of a house before anything else. They produce seed ahead of the hotter weather then become less active until late summer into fall when they build carbohydrate reserves for overwintering. This is why the one-two punch of a spring followed by a fall application with a product containing 2,4-D works well on them.

http://www.extension.umn.edu/distribution/horticulture/DG1137.html

[fishersofmen]

Plenty of time....if you don't get to it this week put it down next week. To be honest you will have better control than everyone else who has put it down and had 5 inches of rain wash most of it away. Sometimes being a bit late to the party works in your favor.

[LwnmwnMan2]

Plenty of time....if you don't get to it this week put it down next week. To be honest you will have better control than everyone else who has put it down and had 5 inches of rain wash most of it away. Sometimes being a bit late to the party works in your favor.

This. What you have to realize, is that while someone will say "I've already seen Crabgrass popping" 3-4-5 weeks ago, chances are, that either it wasn't Crabgrass, or that there were 1 or 2 plants that popped where mid-June there will be 300.

Put it down, you are fine.

Also, Dandelions and Broadleafs have nothing to do with pre-emergent.

Also, also, just as different plants "flower" in a garden at different times, weeds do the same thing.