My plant’s leaves are curling upwards from the middle like a taco shell. Also, the stalks are turning dark purple. The leaves look like they’re crinkly with rounded edges and the stems are streaked. What’s the problem? — Hazey H.
These are the classic symptoms of a Calcium and Magnesium deficiency. If you’ve been adding a Cal/Mag supplement, then it’s possible you have nutrient lockout due to pH fluctuation. Typically, low pH levels will cause the plant to become unable to take in Magnesium and result in the kinds of problems you’re describing. Most nutrient formulations contain enough of these micronutrients for this not to be a problem, so raising your pH level from somewhere in the high 5’s to more like 6.2-6.5 in soil and 6.0-6.3 in a hydroponic reservoir usually will do the trick.
If pH is not the issue, you can add a Calcium and Magnesium additive solution found at any grow shop or online. This is preferable to Epsom Salts and other homemade remedies, and new leaf growth should come out green and un-crinkled. I recommend Suite Leaf’s Cal-Mag Maximizer, a naturally-organic Calcium and Magnesium additive that works in hydroponic and soil applications. Use promo code DANKO15 for 15 percent off anything on the Suite Leaf website until April 7th, 2017.