When I’m getting close to harvesting should there be a change in the colors of the leaves?
Really good questions @AllDay ...
One of the common misconceptions is that the plant needs to be flushed to ensure there isn't nutrients left in the plant/medium which results in the buds being harmful to smoke. The plant's leaves changing color is confirmation that nutrients are depleted. This isn't entirely true...
Nutrients being left in the plant/medium resulting in the buds being harmful to smoke is false.
So why flush then? Well, those who have tried not flushing their plant (when growing with synthetic nutrients) often complain of the buds tasting bad or being harsh on the throat when smoked. But this isn't because nutrients were left in the plant/medium. This is actually the result of chlorophyll being present; Chlorophyll is what gives leaves their green color. In order to reduce harshness and improve taste, the buds should be cured. During the curing process, chlorophyll beaks down.
If your plant is ready for harvest but the leaves are still green, all that means is it will probably take longer to cure to allow the chlorophyll to break down - which will improve taste and reduce harshness. According to Leafly, "After 2 to 3 weeks in containers, your cannabis will be cured enough to provide a quality experience, but 4 to 8 weeks of cure time will improve it even more. Some strains benefit from 6 months or more of curing."
*end long-winded response lol
@AllDay I do agree but with above. However when you're flushing it's different with soil and Coco coir. The time to flush with soil takes much longer from experience. It took almost 18 days off steady water to get ppm low in soil.