Springtime is also the time when vegetables are planted. At least when it comes to cabbage, leeks and radishes. And that's exactly when it's time to protect the young vegetables from pests.
Leek moth and vegetable flies are to blame
The culprits are the leek moths and vegetable flies. These nest in the still young vegetables and eat into cavities. Sometimes you can see this very clearly with leeks when you cut them open. Small corridors can be seen there.
Protect nets
So in order to avoid this pest infestation, you should protect the young plants. This is best done with a net stretched over the beds. To ensure that no pests can get in, the net should either be weighted down with stones or the like at the edges, or buried in the ground.
The vegetables are always protected and can thrive. This procedure also makes sense for all other types of vegetables. Although these are not attacked by said pests, the nets also protect against snails and rabbits.