Hi there - we bought a house with a vegetable garden in the back. It was full of collard greens. When we tried to cut them all down (they had been overgrown for years), many of the seeds fell and now we have new microgreens growing. I can recognize the collard greens, but now there are also pointy leaf seedlings. There are so many of them I figured they were also vegetables, but my husband says they are weeds. Please see the photo. I know the rounded leaves are the collard greens.
Looks like a weed (Galinsoga) to me. Galinsoga (Department of Plant Science) But some vegetables look pretty similar too, like young voluntary tomatillos or ground cherries (their leaves are thinner and stalks are more tender). How To Grow Tomatillos From Seed & When To Plant
No distinctive smell suggests not Brassicaceae or Solanaceae -- so maybe they are indeed the Impatiens as was suggested.
I am worried it is a weed. It has taken over all the collard greens. There is a little flower coming out. See photo.
I am puzzled that the 'pointy leaf seedling' you were asking about in your OP had serrated leaves and the plant in your photo today shows smooth edged leaves. The veins on the leaves are not the same either. Is it possible that they are different plants?
Both Gallant soldier (Galinsoga) and Chickweed (Stellaria) are nasty weeds, that germinate throughout the vegetation period and develop into flowering plants until they finally freeze in the winter. Chickweed is hardier than Gallant soldier, it can survive pretty long even under the snow cover. On the first photo of OP, both weeds are present. There Chickweed sprouts are still tiny, I thought that the question was about the larger weed. Both are pretty common weeds, cosmopolits.
You said it was a vegetable garden : the ones with larger leaves made me think of a cabbage of some sort.