Poor soil quality. The second major cause for a deficiency. The importance of using quality grade horticultural soil cannot be stressed enough. Do not use topsoil from the forest if you are not certain about it’s nitrogen content. Decomposed leaf material contains no nitrogen (obviously since these are the yellowed leaves shed by the trees!) and makes up for a large percentage of forest topsoil. Also loamy and sandy soil are mainly devoid of important nutrients. If you do utilize such soil in guerilla grows, etc. then make sure to supplement it with long term acting fertilizer, or enrich it with a mix of organic nutrients (bat guano, composted soil, etc.) that have sufficient quantities of nitrogen to support plant growth.
Bud growth and yield will be below average if a deficiency sets in during early to mid-flowering.
Heavily fertilized soils like Bio Bizz All-Mix have shown not to be suitable for indoor grows. They contain too much nitrogen, have an extremely high EC (salt) level, and are better used for outdoor where the plants have a longer growth period.The Light Mix offered by Plagron and Bio Bizz is extremely low in nutrients and completely unsuitable for any natural soil cultivation.
Further details and more product suggestions are available in our SOIL GUIDE .
Cannabis is a fast growing plant species and requires generous amounts of nitrogen throughout growth and early flowering. Nitrogen is regarded as belonging to the group of three primary nutrients essential for plant growth. The other two nutrients in this group are phosphorus and potassium. These will be dealt with here separately. Nitrogen is stored mainly in the leaves and shoot tips, which is why it is inadvisable to remove healthy leaves on plants, as these are the “storage house” for important nutrients. The production of enzymes, proteins, chlorophyll and other vital ingredients for healthy development are all dependent on nitrogen. Chlorophyll lends plants their green color which is why yellowing leaves are a telltale sign of N deficiency.
In young plants a deficiency slows growth. The plants are underdeveloped with a poor root zone and small bluish-green leaves.
The leaf tips on healthy leaves may turn brown and resemble the symptoms of over-fertilization. This is due to a disruption in transpiration (since potassium regulates the opening and closing of the stomata on the leaf surface, where water evaporates from the plant and gases such as CO2 are drawn in).
First indications resemble nitrogen deficiency: the lower to middle leaves yellow between the veins until the entire leaves are eventually yellow.
Nutrient Problems Guide “I took your advice and only used the best soil and proper balanced pH water (repotted 4 times to larger pots) and have had the best healthy full plants I have ever
Prevention is always the best policy, so it is a bright idea to develop good habits that decrease the chances of mistakes. First of all, be sure to use the correct nutrients for the appropriate growth stage. Even then, it is a wise idea to only use ¾ the recommended dosage on product packaging. Sometimes, manufacturer recommendations can run things a bit “hot,” which leaves little room for error.
Further indications of nutrient burn are yellow, burnt tips on leaves. This will be widespread as over-fertilisation affects the whole plant. Small, burnt tips are common and nothing to worry about. When the yellowing intensifies and advances, however, it is time to take action. Once leaves start to curl and go brown, they are definitely goners.
Nitrogen is the predominant compound found in cannabis nutrients, especially during the vegetative phase. Nitrogen toxicity will be quickly followed by more severe symptoms.
Unlike animals (humans included), plants don’t put on weight when you overfeed them. After all, plants are a whole different order of organism. They require a balanced and ongoing series of chemical reactions to survive and thrive. Trying to fatten them up with extra feeding is the fast track to disappointment.
- Very deep green leaves
- Bright, Day-Glow green, almost fluorescent tips
- Leaf tips bent at 90°
- Stalks and branches will become deep red, magenta, or purple
- Sugar leaf and calyx tips will turn yellow, then dieback. Unlike the appropriate dieback of leaves during flowering, overfed bud leaves will remain engorged while they yellow, then dieback quickly and crisply
Early indications of nutrient build-up prior to burning can be:
Once your plant’s woes have been identified as nutrient burn, carefully remove all the damaged material. Break off all the damaged leaves. Trace calyx clusters back to their branch and remove the whole florette, just to be sure. Dead flowers and leaves will rot. As soon as possible, flush your growing medium out with clean, pH balanced water. If you are growing with a reservoir, measure the contents with a pH/EC meter and adjust with fresh water.
Nutrient burn can be caused by:
If you are mixing daily by hand, then calm down tiger, less is more with cannabis. Keep in mind that satisfactory results can be obtained with just plain water for the whole life of the plant.
Over-enthusiasm with nutrients can burn marijuana plants. Knowledge is power when it comes to big buds. So, how to prevent and treat nutrient burn?