If the specific strain of weed you are growing shows signs of illness or deficiencies in the plant leaf, this means that fungi, pests, insects, spider mites and other diseases are present in the grow room or in the strain you are growing. It is a must that you get rid of these problems immediately or they will spread at a pace that you wont be able to control, causing you to lose your entire MMJ Harvest. I have only had 1 problem with plant health, and that was spider mites, and that was from a friend bringing his infested plants over to my grow location. I quickly learned how fast they kill your harvest. I also discovered a new way of getting rid of them, using all natural ingredients that can be purchased at your local grocery store.
Preventing & Controlling Plant Leaf Problems
Preventing marijuana plant leaf problems can be as easy as keeping the entire grow room sanitized and clean at all times. Keep the grow room completely sealed off from the outside, allowing you to control the environment from the temperature to the humidity and Co2 Levels, at the same time, keeping bugs and mites out. Keeping the air clean using a can fan charcoal filter will help with smell and odors, as well help keep the air circulating keeping mold out and giving the plants Co2 from the fresh air thats present in the room.
Most Common Plant Leaf Deficiencies and Remedies
Bigger leaves are turning a yellowish color while the smaller leaves are green.
Nitrogen deficiency – add nitrate of soda or organic fertilizer.
Older leaves will curl at edges, turn dark, possibly with a purple cast.
Phosphorous deficiency – add commercial phosphate.
Mature leaves develop a yellowish cast to least veinal areas.
Magnesium deficiency – add commercial fertilizer with a magnesium content.
Mature leaves turn yellow and then become spotted with edge areas
turning dark gray.
Potassium deficiency – add muriate of potash.
Cracked stems, no healthy support tissue.
Boron deficiency -add any plant food containing boron.
Small wrinkled leaves with yellowish vein systems.
Zinc deficiency – add commercial plant food containing zinc.
Young leaves become deformed, possibly yellowing.
Molybedum deficiency – use any plant food with a bit of molybdenum in it.
See the section Spider Mites, If this section did not help you with determining the exact deficiency your marijuana plant leaf has.