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Guide to Plant Deficiencies

Discussion in 'Marijuana Plant Problems' started by mjnme, Oct 9, 2008.


    mjnme Well-Known Member

    Panda’z Nutrient Deficiency Guide

    Nitrogen Deficiency:

    Entire plant is light green in color; pale plants.
    Lower leaves are yellow; red stems.
    Growth is stunted; smaller growth.

    Add any chemical fertilizer containing N.

    Recovery Time:
    About a week

    Why this happens:
    Simply put, your plant isn’t getting enough Nitrogen! Nitrogen produces chlorophyll, amino acids, and is in charge of photosynthesis. Proteins and enzymes are also overseen by NITROGEN! When your plant is not getting enough Nitrogen, many of these productions are stopped, much like in a factory, and that is when you begin to see the deficiency.

    Nitrogen deficiencies can be confused with other deficiencies like Magnesium. You know you have a nitrogen def. when the deficiency begins around the tips of your leaves and continues into the leaves. If you happen to be having a slow growth and the same yellowing, it’s probably a lack of N.
    Again, it happens to be that during the flowering stages, mostly smack-dab in the middle of the flowering stage and towards the end, it will show these symptoms. This is normal for the plant. Don’t even think of using nitrogen at this point!!! Let the plant go it’s natural way, it’s using out it’s stored nutrients.


    Phosphorous Deficiency:
    Entire plant is bluish-green, usually develops a red or purple stem; Purplish, yellowish, and dull blue on some leaves;
    Lower leaves are yellow and when they dry they turn a greenish-brown, even black color; Smaller leaves are dark green; Curled leaves at times;
    Growth may be inhibited or slow;

    Add any chemical fertilizer that contains Phosphorous.

    Recovery Time:
    You will not see the affected areas get better, but your new leaves will show no deficiencies in P.

    Why this happens:
    Phosphorus is another important nutrient. When the plant is having a lack of this, it again, begins to lose it’s color. Phosphorous stimulates root growth, and germinates seedlings. It’s also used in reproductive (flowering) stages. Since phosphorus stimulates and germinates, when you are having a deficiency, you are not receiving as much of the other nutrients as you should, causing an over-all deficiency in your plant.

    Phosphorus deficiencies can be confused with fungus problems. This is because sometimes the tips of the leaves look like fungus. Phosphorus deficient leaves feel (to the touch) like a ph problem.


    Potassium Deficiency:

    Leaves look like paper; Color pale and/or yellow; Red stems; Older leaves have patches of different colors; Leaf will turn yellow between veins at times.
    Dead areas along the edges of leaves, and lower leaves; Burnt-looking tips and edges;
    Plant might just stretch; its branches are weak, and can be broken too easily;
    Growth is stunted; bud growth is stunted;

    Add any chemical fertilizer containing K.

    Recovery Time:
    The plant itself will begin to show healthiness after 4 or 5 days of being given the nutrient. The affected leaves will never get better.

    Why this happens:
    Potassium is a nutrient that is the all-important development of the buds during the flowering stage. Potassium gives you thick stems, helps with the resistance of plant diseases, and helps with photosynthesis. Potassium takes care of water transportation, thus important during ALL stages of the plant’s life. When it is deficient, your leaves will 1. Not receive as much water, 2. Have weak stems, 3. Grow slowly, and have yellow leaves since the photosynthesis is not being processed.

    Potassium deficiencies can be confused with iron deficiencies. You know it’s a potassium def. when the leaf’s tips curl and its edges looked burned. Leaves might be red AND curled.


    Magnesium Deficiency:

    The lower leaves begin to die; lower leaves turn yellow between the veins; green veins; crispy leaves;
    Blades die and curl upward; tips of growing leaves can turn bright green;
    Starts at the bottom of the plant and eventually works its way up if not treated;

    Any chemical fertilizer containing the nutrient Magnesium. Be careful though as to not give NUTE BURN.

    Recovery Time:
    A few days and your plant will be healthy again. The affected areas will not get better.

    Why this happens:
    Magnesium sustains healthy veins, healthy leaf production, and a healthy plant structure. Mg. helps produce chlorophyll and breaks down enzymes.

    Magnesium deficiencies can get worse if you give it more nutrients. That is because there might be a pH problem, that’s not letting the plant absorb the nutrient. In this case, adding nutrients would really hurt the plant instead of making it better.


    Calcium Deficiency:

    New leaves die; New stems die;
    Tips of leaves may curl;

    Plant growth is delayed; Weak stems and nodes/branches;
    Weak root system;
    Yellow and brown spots on leaf tips; on new growths; edges of leaves;

    Feed your plant some calcium!

    Recovery Time:
    Give it about a week.

    Why that happens:
    Calcium supports the cell walls in the plants, as well as making the whole plant stronger. It supports root growth and contributes when retrieving potassium in the roots.

    Too much calcium will cause other deficiencies…



    mjnme Well-Known Member

    i made this for all the posts that might pop up that are thinking ...
    what is this
    whats wrong with my plant

    i'll finish the guide tomorrow =)

    714steadyeddie likes this.
    mr west

    mr west Well-Known Member

    subscribed , in tresting stuff

    Boneman Well-Known Member

    Great post but the questions will never stop

    erickw1822 Active Member

    can you take a look at my gallery and tell me what my problem is??? thanks

    helpmegrowbro Member

    hey dude can u tell me what is wrong with this plant?

    Phenom420 Well-Known Member

    Hey it's hard startin out, too me lots of things look the same to me, I feel like a idiot a good deal of the time, so I would rather ask than screw it all up....
    That's probably why my girls have made it this far is I learned to ask before I screw it all up..

    Happy toking!

    BlackRoses Well-Known Member

    Thanks, needed this thread to look up some deficiencies in my plants..
    I think it's a combination between K and N..

    fadangle Member

    where do i get calcium.

    NoobGrower416 Active Member

    I recently moved from outdoor to indoor growing with my new 1000w hps for flowering and T5's for veg. (I've only been growing for about 2 months...spent MANY all-nighters with the bong and some OG Kush filling my head with knowledge from these forums and elsewhere (videos, general cannabis and non-cannabis plant growing guides)

    I use rainwater for everything except nutrient mixing! I make my own Cal-Mag suppliment by using TAP WATER instead of rainwater and mixing it with Epsom salts, I learned somewhere that trace amounts of calcium are found in tapwater, adding a little Epsom salts will add Mag and Sulphur to your Calcium enriched tap water! From what I've learned the calcium from tapwater is good SOMETIMES for suppliments because regular use will cause PH problems or mineral buildups (minerals like copper erode off of water piping/water treatment filters, theres no getting around it.)

    I'm also an Apprentice Plumber so it helps when dealing with water :D

    MarkDoesWork Member

    Thank you so much for all of this insight. I'm a new grower with my first batch of medicine a month and a half out, and noticed my leaves were crusty, dark (brown/black/dark green/its a mess). This was only the older undergrowth, but I didnt want that to progress to my beautiful buds coming in. Frantically i searched the internet looking for help. This is where I found it. I thought giving grow big to my plant (which had never had sufficient nitrogen in fert) would help it. The problem progressed.

    This feed told me that my plant is Mg deficient, told me NOT to fert it, or i can progress the problem, and offered a solution. Mind you, I wish it said Epsom salt as a fix (cause that's what i found elsewhere and am going with), but this is a godsend. You saved my lovely lady's life. :] Thank you!!!

    P.S. About to administer some epsom'd water. Here's hoping my strawberry cough makes a full recovery!

    sulphur Member

    Hey guys, can anyone help me out? I don't know what my problem is. 20120207136.jpg

    lilrich11 Active Member

    WOOT Go plumbers, Also a apprentice plumber. But WAY more simple just to go out and buy some distilled water....

    LlAR Member

    calcium- grind up some eggshells. contains ~90% CaCO3.
    Magnesium - epsom salt

    if you fucked up and need to flush, use water + molasses to flush
    cannn likes this.

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