hey there RonnieB, foliar feeding makes a huge difference at all stages of the plant's growth. that's because leafs absorb most nutrients with an efficiency of 80%+ whereas roots have an absorption efficiency of something like 20% more or less depending on pH and chelation. So clearly if you spray , you can spray nutrients as well as cal mag with great results. to spray nutrients try spray kelp extracts which also contain auxin, the plant growth hormone. In fact the first three weeks from seed , you can spray the plant up to 6 times a day. cal mag is a great one to spray also, twice a week if you need to , or if there's a deficiency, it will make the plant rebound almost instantly. great technique to have ! Hope this helps ! 🚀