My general rule of thumb for harvesting my plants based on trich color is 10% clear, 75% milky, and 15% amber. However, this is just my personal preference. Through experimentation and note taking with each crop, you can figure out what ratio will be the most ideal for you and your customers.
One thing to remember though is that the ratio outlined above is just a general guideline. You will almost never be able to get it that precise, especially since every plant is different. Sometimes you will still have 20% clear when you’re already getting 15-20% amber.
The main point to remember is you want to harvest with over 50% of them cloudy, for the best overall high.
More indicators I look for to determine harvest time
Hair (or “pistil”) color on the buds
Years ago, back before the internet and weed becoming more legal and accepted in mainstream society, one of the main factors growers looked at was the color of the hairs on the plant. The plant starts with white hairs on the buds, these are actively growing and alive trying to receive male pollen to pollinate the plant so that it can produce seeds and “survive” for another season.
As the plant ages through the season some of these begin to turn brown until eventually if you let the plant go long enough it will stop growing new hairs and will stop most growth in any area of the plant. Growers generally want at least 85% of their hairs orange or brown before they harvest.
This isn’t as precise as the trich color, but when combined with the trich color and my next sign, it leads to making your harvest decision even easier. But remember, all strains are different. I have personally grown plants that for one reason or another had 85% orange hairs by week 7, and the plant still had at least two more weeks to go before harvest.
When the bud looks “done”
The final factor I want to discuss is the most vague and requires the most experience to get right. But this far into my growing career, it’s essentially the only real factor I look at. This will be difficult to explain, so if you have any further questions leave them in the comments below.
The simplest way I can describe the plant being done is when the bud looks “done”. Now I know that sounds vague and pointless, but let me explain.
Consider how a marijuana plant grows in the wild and its growing seasons. As the plant approaches winter, it produces seeds, or in the case of plants that haven’t been pollinated (like hopefully all of the ones you are growing), the plant has certain signs that let you know it has given all that it had to give.
If a plant is pollinated, it will have thousands of large seeds on it ready to fall into the soil so that it can come back the next spring. These seeds are in pods that protect them until they fall from the plant. These pods are the “flowers” that we all love and smoke on a daily basis. The difference is just that ours do not have seeds in them – they are only plant matter covered in trichomes.
Just like if the plant were seeded, our plants without seeds, will still have these engorged pods. They will swell up as the plant nears the end of its life. The entire bud will take on this swollen look as it packs on the majority of its weight in the last two weeks.
What about the leaves?! This is a factor that isn't always accurate (especially with some sativa/sativa dom strains) but if the plant is healthy, the leaves will usually yellow throughout the budding process and begin to die as they feed their energy to the ripening buds. With some strains, the color is not always yellow, the leaves may turn purple, black, red, etc - but there is a definitive change there regardless..
Cool write-up and nice photos!