Back. 1  Vitacost Chromium Picolinate -- 500 mcg - 300 Capsules. 4.5 out of 5 stars 11. 2  Vitacost Strontium -- 680 mg per serving - 240 Vegetarian Capsules. 4.6 out of 5 stars 19. 3  Vitacost Glucomannan -- 2000 mg per serving - 180 Capsules. 3.7 out of 5 stars 51.
The most common cause of marijuana leaf cupping aka leaf margin rolling, leaf margin burn, and leaf tip curl/burn is overzealous use of marijuana plant food. In relationship to factors such as marijuana plant vigour and rate of growth. Leaf burn is often the very first sign of too much marijuana fertilizer.
Comments. 1  I also have a plant (no bloom) with long leaves that are kind of crinkly but the ends of theleaf turns black. 2  Not sure what type of plant it is. 3  Black leaf tips are more likely to be caused by underwatering than overwatering. 4  Howdy! 5  Hey There.