This picture is taken about 2 weeks after planting the seeds which were taken straight out of the seed pods from the spring plants.
I don’t remember exactly what variety they were but most radishes are quick and should be ready around 25-30 days . Around the tail end the size can be checked by obviously just pulling one out or digging gently around the radish if you do it this way if it’s too small just bury it back up no harm no foul as long as you didn’t yank it out, same goes for onions, carrots and similar vegetables. To small and they aren’t done growing too large and they get a unpleasant woody texture and usually are spicier.