>>2450882>>2451776An overdose of fertilizer can easily kill young plants, yes. Best to be very sparing with it till you know what you're doing, underfeeding is better than over feeding. If you are using a commercial potting mix it will be pre-fertilized, you won't need to add anything but straight water for some time.
My poor reaper peppers are teasing me. It was such a cold spring they got stunted early and still behind. Usually by now I'd be picking lots. I know the wait will be worth it though.