I’ve got some high-grade, commercial Mexican marijuana growing indoors. The plants have been flowering for nearly 70 days and there are a lot of stigmas still there. How can I tell when the marijuana buds are mature?
The ripening periods for indicas and indica/sativa marijuana hybrids are pretty clear. When the the two stigmas recede into the ovary, the marijuana plants are ripe. The ovary starts to swell when the glands covering it balloon with THC.
Mexican sativas, on the other hand, need about 85 days to ripen with 12 hours of darkness. Their ripening periods are slightly different than indicas. The stigmas start to turn brown and become dry, but they will recede only slightly into the ovaries (which get only a bit larger). The harvest for the Mexican sativa typically occurred in November or December and the plants flowered for 12 weeks.
If you want to speed up ripening, then you can make the dark period equal to 14 hours instead of 12. Let the medium stay drier than normal. Although this is difficult with hydroponic systems, other mediums all you to alter the amount of daily irrigations. Also be sure to use a fertilizer with a lower concentration of nitrogen.