Trying again with pumpkin patch

[Juank1979]

Hello everybody, I'm here again trying with my pumpkin garden.
Could somebody give me an advice about what kind of fertilizer do I have to use in early plants to help them to grow better and be more resistant in vine borer´s atack later.
Another question is when do I should start covering the plants to protect them for pests with row cover. I´ve planted them about 3 weeks ago, they are about 12 inches now.
Thanks in advance for answering my two questions.