I have these weeds and I am not sure what they are and have tried all kinds of stuff. I could give details if you need. Last message with all the details got erased. Despite all the measures, these weeds seem to be spreading. Please help. Not sure if you can see. I have a thin grass with a tall stalk that is different from the one with the tiny leaves in the pictures. The top of the stalk has a reddish brown color. I have been calling it Poa annua. Not sure if that is what it is. Let me know if you need pictures. I am also losing the battle with that one. I’m guessing I need two applications of Tenacity in the fall for that, but let me know if you have a better idea or if there is anything I can do about it at all. Here in the Cumberland Maryland area, it is everywhere including the highway medians.
Allegany County Maryland
Hi - The weed in your second photo is called hairy bittercress (Cardamine hirsuta). It is an annual weed that thrives in the cool spring weather. Eventually the plants die down when the weather gets warm, but they are notorious for their effective seed dispersal prior then! Hairy bittercress tends to show up in bare spots or where lawn is mowed too short. Fortunately, it is very easy to pull out. Here is our webpage about this plant and how to manage it in a lawn, https://extension.umd.edu/hgic/topics/hairy-bittercress
We will need to see better photos of the other weeds to determine what they are. The weed in your first photo looks like it has tiny pods, like a type of peppercress, but I cannot tell for sure from the photo if those are pods.
The weed in your third photo does not look like Poa annua, but again, it is difficult to see the details. Poa annua gets a branch of multiple flowers that are light yellow/straw-colored, not reddish-brown. There are good close-up photos on this page, for comparison. https://plants.ces.ncsu.edu/plants/poa-annua/
If you can provide additional close-up photos of the plants in question, we would be happy to take another look.