Grow Diary Granddaddy Purple

Granddaddy Purple – Week 4

Today marks day 26 since emergence, and both Granddaddy Purple plants have officially entered their transition period after the 12/12 flip. They were given four full days to recover after being topped above the fifth node, and both responded with explosive growth. We're now two days into transition with no pistils yet, which is completely normal as the plants shift hormonally before flower initiation.

This week brought massive vertical gains. GDP1 grew from 11.25 inches to 21.5 inches, and GDP2 jumped from 12.5 inches to 23 inches. The stretch has been fast but controlled, with tight internodes and strong lateral growth. Every node is now being actively trained outward to create width and airflow before the real stretch begins. The structure is balanced, and the canopy is wide and even, which is exactly what I wanted going into flower.

Nutrient strength remained moderate throughout the week. Each plant received a blend of late-veg and early-bloom food at around 895 PPM, with the solution pH adjusted to 6.1 for optimal uptake in PRO-Mix HP. Silica was increased to 2 mL per gallon to help fortify the stems ahead of stretch, along with Cal-Mag at 4 mL per gallon. The plants handled the nutrients perfectly with no tip burn or signs of overfeeding, and the leaf color remains rich, uniform, and healthy.

Low-stress training expanded significantly this week. All nodes are being spread outward - first the lower branches, then the mid-tier, and now even the developing top colas are beginning to receive gentle directional training to prepare for stretch. During this process, one branch on GDP2 suffered a small split near the node. I stabilized it with tape and plant ties, leaving airflow around the wound. It hasn’t wilted or leaked sap, which would mean the vascular tissue is intact and it should heal over the upcoming week.

Lighting remained steady and controlled. I didn’t change the dimmer at all this week; instead, I raised the light incrementally as the plants grew so that they moved naturally into the 600–650 PPFD range. DLI stayed stable at 26–29 throughout the week. Before topping, the plants were receiving stronger light as they grew upward, but after topping the light was raised to reduce stress, and then brought back down to transition intensity once stretch began.

UVA was increased from 30 minutes to 45 minutes daily with no signs of stress.

Overall, Week 4 was a dramatic and successful transition. The plants recovered beautifully from topping, took to training without issue, and are now building the structure they need for strong flowering. Stretch is underway, vigor is high, and everything is positioned perfectly for pistils to appear soon as the transition ends and true flower begins.