Sprouting green things

Many of the seeds I have planted have transformed nicely into little sprouty green things, which I believe is the goal for most seeds. In fact some of the seeds I have planted have taken off a little too well, as they are already outgrowing their baby pots! I would not normally be bothered by this fact but since the weather is being so slow to turn springy I'm worried many seedlings will outgrow their pots (and my house) before I can get them in the ground.

The first photo is of turnip sprouts...these little devils shot up over one night! The directions on the seed pack indicated that they are direct sow, meaning I didn't need to start them indoors, but I did (because I like being awkward like that). The second photo is of spring onions - exciting, no? The third photo is one of four zucchini plants that are doing really well, so leafy and green! I wish so badly that the snow melts so I can get a move on making their garden beds.