I am growing spinach in pots and up to now have been enjoying picking the baby leaves. Since last week the leaves look like something has worked it's way inside them and they are papery thin and dry. Also I found a kind of black/grey grub inside a leaf yesterday. Is this leaf miner?.
It had already bolted so I was going to pull it up anyway. However, as I am going to plant some more (only for baby leaves), can I do it in the same soil (with addition of compost)if they might have leaf miner or do I need to throw soil away?