When nutrients such as magnesium, calcium, potassium, phosphorus and nitrogen are lacking, plants respond in a variety of ways—oftentimes in the leaves. Nutrient deficiencies in plants are hard to spot and are often misdiagnosed. All the fan leaves on my plants have purple stems, however the new growth shoots have green stems (see pics to see what I mean). It won't cause all the stems to turn purple, just the new growth. Cauliflower stems turning purple.
If your plant seems to be in good condition aside from the stems being purple, refrain from making any changes for a one or two weeks. Also, all lower growth leaves tips are turning yellow, and eventually brown. what do purple stems on seedlings mean i got them in rookwool cubes

While some peppers, such as bell peppers, commonly have purple or black stems that are completely normal, there are some diseases that do cause discolored pepper stems. allso they eat up the nitrogen more than other plants do.mine seem to anyhow. This would mean your plant needs more cal-mag. Best way to tell would be to look at the leaves on the outside and look for yellowing that turns brown. The majority of the time the plants will turn green fairly quickly. . Hi, I grew broccoli and cauliflower from seed and transplanted them into the garden on Memorial day, exactly three days ago. The top is green and its flourishing. i think its in the genetics.as my killers have purple stems all the time .allso my blue cheese grows purple stems allso.. i think its down to the thai side in the blueberry ,as a guess that is.? Asked June 2, 2017, 12:27 AM EDT. My stems are turning purple, and any leaves that are connected to the purple area seems to be withering. i also use liquid seaweed and cannazym. Other strains, especially those that show stems of seedlings that have turned purple, and have no other issues, have been genetically modified to do so. Plant deficiencies are often encouraged by a number of factors including poor soil, insect damage, too much fertilizer, poor drainage or disease. Solution for purple stems. Here are some pics. I run about 2.5ml/gl of GH Flora Nova Bloom and Grow. For some peppers, purple or black stems are normal and as long as the plant looks healthy, you shouldn’t worry about the dark coloration on the stem. My starts were thriving, bright green and sturdy. Lately its been doing good, and still is, but I want to know whats causing this?
Some marijuana strains naturally grow purple stems which cause their budding seedlings to appear even more purplish in cooler temps at night.