Another thought to keep in mind for healthy root growth; first of all, we tend to give an over abundance of nitrogen, so I feed mostly flowering nutes unless the plant asks for some nitro by just begining to pale. P & K for flowers & stong stems.... & roots! ( I do use growth nutes when in RAPID veg growth, but gently, never MORE than recommended strength). This works for me. My fav for this, & seedlings first few feeds..... fox farms big bloom. Also, my seedlings always have really sturdy stems. No floppy fall overs! When in veg, I do supply a diluted foliar feed of nitro once a week. Just keep in mind that bloom nutes do more than just feed buds. Makes healthy stem & ROOTS too ! (I always give transplants a shot of big bloom because of what it does for root health! ) I never follow the recommended nute program, I tweek a nute here & there according to what the plants tell me.