Here is the picture of the sprouts, couldnt get it to appear in the main post for some reason

Well nigh impossible to id at this stage, I'm afraid. The red one could be a tree of some kind. If you dig down do you find a pit or nut? The one on the left is out of focus but I'm wondering if it's corn.

Let's be honest here. If these containers were sitting outside, they got rained on by all manner of airborne weed seeds. That's largely how weeds happen. They get blown in. Lots of weed seeds wait until it warms up before they ever try to germinate. In fact, I can't imagine a container being left outside for a year that won't have weeds coming up in it in the spring. Scout around outside where these containers were sitting, and you'll probably find more of these plants.

If these containers were kept inside, they can pretty much only be leftover seeds from what you previously planted. Some varieties of radish do have dormant periods.