pistils turning brown after 21 days in flower?

wait longer

Looks pretty normal to me. Pistils turning brown is just part of the flowering process, especially if you’re a few weeks in. It usually means the buds are maturing. As long as they’re not all turning brown too early or curling up like they’re burnt, you’re good. If you’re around week 4 or later, this is expected. Just keep an eye on trichomes for ripeness — pistils alone aren’t the full story. Could be getting close to the finish line. Only time to worry is if it’s happening super early, or if you’ve got other stress signs like burnt tips, crazy heat, or if a hermie snuck in and pollinated something. From the looks of it, though, she’s doing fine. Keep it rolling!

is there excess wind in these locales? this can cause early maturation of pistils. So can pollination. Give it a good inspection. Also, some people have esoteric ways of counting 'flower' days and if it is an autoflower, it makes it more of a guess and even greater volatility between reality and what people perceive as length of flower etc.. 21 days from flipping to 12/12 is definitely too early. some external factor like wind or a foliar spray could cause it and so could a hermie. An autoflower goes into flower phase about 7 days before you can see the preflowers. As with a photoperiod, it is in flower long before you can see it with the naked eye. It is about the biological processes taking place inside the plant and not what you can see that matters. So, "21" days might be closer to 28-30 days and at that point a few rusty pistils is much less of a concern. Give a good inspection put fears of pollination to rest. if a fan is directly pointed in thsese areas, point it in a less direct fashion.

This could be natural progression. you couldve touched it. the fan could be too aggressive in that one spot. potential pollination or you accidentally sprayed with water or dropped water on it. but either way your plants are looking great and they are going to be

That an absolutly normal ripening process of the flower, they start white & Turn brown and dryer… It depends on genetics when These process starts, with some genetics the pistels stay white even in harvest window, but most of the times pistels going to become brown… If it‘s too early in the process it could also be a sign of too hot Temps, but it don‘t look like that at the moment

Stress, physical contact, or simply fast-maturing genetics: An early browning of pistils can be caused by various stress factors—such as excessive heat, low humidity, lights that are too strong or placed too close (e.g., LEDs), nutrient imbalances, or incorrect pH levels. In such cases, the plant may react by accelerating its maturation as a protective response to the stressful environment. Frequent physical contact—like touching the buds, strong airflow, training techniques, or parts of the plant rubbing against each other—can also lead to localized browning of pistils. This is usually harmless and limited to specific areas. However, it’s also entirely possible that the early browning is simply due to fast-maturing genetics. Some strains—particularly indica-dominant or autoflowering varieties—naturally develop brown pistils just a few weeks into the flowering stage. In that case, it’s completely normal and nothing to worry about. Your ladies looking very strong and healthy. Good Job! Keep growing like this!