Why are my stems purple or red?Updated 2 days ago

Purple or red stems can be caused by several factors, including genetics, phosphorus deficiency, pH imbalance, or cold stress.

If your strain isn’t naturally purple, here’s what to check:

• 🌡️ Temperature: Keep night temps above 68°F (20°C) — cold nights restrict nutrient movement and cause color changes.

• ⚗️ pH Balance: Out-of-range pH can cause phosphorus lockout, leading to purple stems even when nutrients are sufficient. Keep pH between 5.8–6.2 (coco/hydro) or 6.0–7.0 (soil).

• 🌿 Nutrition: Slightly increase Bloom (0-5-3) or Clyde (3-6-5) to ensure adequate phosphorus during the early flowering phase.

Some coloration is harmless and genetic, but if purple stems appear alongside slow growth or pale leaves, it’s a sign of a nutrient uptake issue — usually linked to pH or temperature.