We're talkin' nutes! Nitrogen, Potassium, and Phosphorus

We’re getting ready for the next season and are making sure we have all the nutrients we need for the growth cycle.  Nutrients are an important part of cannabis growing and need varying quantities during the growth stages, luckily there are plenty of blends and teas formulated for both the veg and the flower stages available.  When looking at these blends, the listed nutrients are listed by their symbols of NPK with a number of their ratio to the blend.  N for nitrogen, P for phosphorus, and K for potassium.  The ideal ratio of these nutrients depends on the growing medium with soil needing only a small amount since the soil blend should already have nutrients in it.

Cannabis growth happens in four cycles, seedling, grow, bloom, and flush.  The flush cycle isn’t actually a cycle, it’s the last step before harvesting. Cannabis seedlings don’t need too many nutrients.  As long as they are being grown in a medium like soil that contains the nutrients seedlings need, no nutrients will need to be added.  When growing hydroponically, however, seedlings do need minute amounts of growth nutrients, at about 10%-25% of the normal strength.  Nutes should be given to seedling for only about the first two weeks after the first true leaves appear.

After up-potting the seedling into a bigger pot, cannabis plants enter the growth or veg stage.  This is when the plant grows big and can be trained for maximum bud growth.  During this stage the cannabis plant needs more nitrogen to develop leaf growth, the nodes where the leaves grow is where the buds develop later. During this stage, the ideal ratio of NPK is 7-5-5.

The veg stage lasts about 3-16 weeks with the last two weeks being dedicated to transitioning to the flowering stage.  During this time the nitrogen can begin to be lowered with the potassium and phosphorus can be raised until the ideal ratio of 3-10-10 is achieved for the flowering stage.  The flowering period lasts about 8-11 weeks with the final 2-3 weeks dedicated to flushing out all the nutrients with pH balanced water, any leftover nutrients can create a harsh taste.

It is possible for plants to receive too many nutrients, and they'll show signs of either their deficiency or excess of any nutrients.  These signs are most visible in the leaves with each nutrient having an unique effect on the way the leaves turn color or begin to fall off. Too much nitrogen and the leaves turn dark green and curve into what many growers call "The Claw," not enough nitrogen and the leaves begin to yellow and fall off.  You'll see this during the last weeks in flower when the plant uses up all the remaining nutrients starting with nitrogen.  During this time is normal, seeing yellow leaves during veg is not and the nitrogen should be adjusted as needed.  

Cannabis requires many nutrients to grow, the main ones we discussed are just the beginning.  To learn more about nutrients and cannabis click here and here.