Feeding Nutrients

I have a blueberry auto that’s 2 weeks in and growing well. The embryo leaves are yellowing up so I know it’s almost ready to hold its own real soon. The question I have is when would be a good time to start feeding the plant food to make sure there are no nutrient deficiencies of any kind and all that other good stuff? The soil I have it in is slow release nitrogen and this coming week will make it 3 weeks old. Another question I have, is there a certain kind of liquid plant food to give it since it is an auto?

You don’t need a different nutrient mix because it is an auto. Regular photo period strains and auto flower strains will need the same nutrient mixes and concentrations at the same time of their development, more nitrogen in the NPK ratios during the first stage of its life – the “vegetative” stage, and less nitrogen and more phosphorous in the NPK ratios during the latter stages of its life – after the plant has started developing its flowers.