mysticepipedon
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One of the posters in another thread requested that I post this separately, in hopes of making this a pinned thread. If any of the seasoned growers think it's about right, maybe it should be pinned. If not, please post corrections and maybe we can have a decent pinned post for people wondering why the leaves on a plant aren't behaving themselves and being green. I didn't want to post a bunch of pics of deficiency and toxicity photos. There are plenty of those around, already. And maybe step 5 should be removed, and prevent a slaughter of farm animals and pets.
The original post:
Certain deficiency symptoms, like magnesium (Mg), nitrogen (N) and potassium (K), you will see again and again, because they are so common.
If it's not an obvious one that you've seen before, start thinking about things in a step-wise manner:
1. What part of the plant is showing the symptom? Is it a growing point or mature leaves? If it is a growing point, the problem is an immobile nutrient in the plant. If it's a lower leaf, the problem is a mobile nutrient in the plant. ("In the plant" as opposed to "in the soil.")
2. Is your pH in the right range for your media/method of growing? If not, the nutrient might be in the soil, but it's not in a form the plant can take up. Adjusting the pH can make the nutrient more soluble and plant-available.
3. Is there any reason to believe an interaction with another nutrient is causing lockout? The reason could be that you just recently added a lot of calcium (Ca), phosphorus (P) or N. Look at the Mulders Chart to get a handle on possible nutrient interactions.
Mobile nutrients include N, P, K, and Mg. These show up on lower leaves.
Immobile nutrients include Sulfur (S) — though some texts say it's mobile, Ca (though sometimes it's a little mobile), and just about all the micronutrients (the metals, like iron, manganese, copper, zinc, nickel). These show up on growing points.
Deficiency symptoms on lower leaves never go away when you fix the problem, so don't expect it. Deficiency symptoms at growing points usually do go away when you fix the problem.
4. Once you know whether it's a mobile or immobile nutrient, look at the assorted charts and pictures of the specific symptoms in a google search.
5. Sacrifice a goat* at an alter in front of your tent to let the plants know that you are on the case and searching for guidance.
*Two chickens and a hamster can substitute for a goat.
The original post:
Certain deficiency symptoms, like magnesium (Mg), nitrogen (N) and potassium (K), you will see again and again, because they are so common.
If it's not an obvious one that you've seen before, start thinking about things in a step-wise manner:
1. What part of the plant is showing the symptom? Is it a growing point or mature leaves? If it is a growing point, the problem is an immobile nutrient in the plant. If it's a lower leaf, the problem is a mobile nutrient in the plant. ("In the plant" as opposed to "in the soil.")
2. Is your pH in the right range for your media/method of growing? If not, the nutrient might be in the soil, but it's not in a form the plant can take up. Adjusting the pH can make the nutrient more soluble and plant-available.
3. Is there any reason to believe an interaction with another nutrient is causing lockout? The reason could be that you just recently added a lot of calcium (Ca), phosphorus (P) or N. Look at the Mulders Chart to get a handle on possible nutrient interactions.
Mobile nutrients include N, P, K, and Mg. These show up on lower leaves.
Immobile nutrients include Sulfur (S) — though some texts say it's mobile, Ca (though sometimes it's a little mobile), and just about all the micronutrients (the metals, like iron, manganese, copper, zinc, nickel). These show up on growing points.
Deficiency symptoms on lower leaves never go away when you fix the problem, so don't expect it. Deficiency symptoms at growing points usually do go away when you fix the problem.
4. Once you know whether it's a mobile or immobile nutrient, look at the assorted charts and pictures of the specific symptoms in a google search.
5. Sacrifice a goat* at an alter in front of your tent to let the plants know that you are on the case and searching for guidance.
*Two chickens and a hamster can substitute for a goat.