So the bottom half of my 11 ft high Sativa its flourishing beautiful flowers with around 3 weeks to go before harvest. The top half, or probably the top 3rd of the plant is more spindly and has gone yellow. I have done all the usual soil tests added the usual default fertilizer etc, the other 2 plants growing in the same soil have no similar problems at all. The plant has no structural damage and the stem is a bit yellow too. Any help appreciated. Yllowtop2 by Weedmedic posted Apr 4, 2016 at 5:30 AM Yllowtop2 by Weedmedic posted Apr 4, 2016 at 5:30 AM
Soil PH level? Starting on top half could be an iron deficiency. Sent from my iPhone using Grasscity Forum mobile app
Hmm, if you have any additives with Iron and/or Sulfur I would add it. Majority of top leaves yellowing are either iron/sulfur due to PH imbalances or root bound. You're outdoor so probably not bound. PH may be potentially off lower in the soil. Sent from my iPhone using Grasscity Forum mobile app
Rain water from the water tank daily and tap water for a really big soaking once a week or when its been super hot.