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those leaves!#?#!

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heh stoners,

... So there are pretty distinct symptoms that will tell you that you have

over-fertilised your plants, the fan leaves will tell you soon enough.


But i was thinking more on the side of leaf diagnosis and watering/

moisture levels, ie from looking at the fan leaves on a plant that is

relatively healthy, correct PH, healthy root structure, showing no

signs of being over-fertilised, can you establish whether you are

under or overwatering or whether you have too much light/heat or

a combination of all these factors.


So like without moisture meters, picking up pots, temp. guage... whatever, no tools, can you diagnose from looking at the leaves only... if the plant is receiving too much moisture intake, how can you tell? If the plant is absorbing moisture at a faster rate than what the root structure can supply (underwatering),how can you tell?


Too much and high heat and the rate at which the plant, supported

by its root structure, is able to effectively draw moisture are intertwined and go hand-in-hand. High heat, for example, draws moisture out of the leaves faster than it can be replaced... first signs are the leaves raising themselves to the light source to conserve the last reserves of moisture they have... once this has depleted, the leaves lose their energy and begin to droop.


This Uncle Ben fella' explains it pretty clearly:


"All of the above issues relate to a plant's internal cell turgor or cell water pressure. If water pressure within the plant's stem and leaf cells are positive, the plant will look strong and stocky with flat leaves that are cool to the touch due to good transpiration from the leaf surface. By the same token, if the water pressure is not up to par, whereby water is being

extracted from the plant and not replenished like it should be.... the leaves and/or stems will droop."


... yeah well sometimes the reason why the leaves show you these things are hard to pinpoint in a short time. Sometimes a mis-diagnosis will make matters worse eg maybe you think your underwatering because the leaves are beginning to turn upward... but maybe also

this could be caused by high/too much heat/light... if you don't fix the heat/light problem, stepping up the watering cycle might only mean your damaging the plants further and so on.


Is there a really simple way to tell if you are giving your plants the correct balance of moisture by lookin at the fan leaves? .... How should the leaves look if they are being given their correct weight? I hear so much about optimum watering ... waiting to medium drys out, making the plant strive for its moisture etc. I'm sure at any time by studying your fan leaves you would be able to diagnose what sometimes can be a huge problem!


Made a couple of notes from other sources and some of my own thoughts.... need help, problem is shitting me... i realise like there's heaps of variables but there has to be some universal truth in it all.


Overwatering: What your leaves are showing you...


- leaf stress

- slow/stunted growth

- leaves usually droopy


Underwatering: What your leaves are showing you...


- leaf stress

- stringy/whispy growth growth

- leaves point upward to the light


High Heat: What your leaves are showing you...


- leaf margin cupping or rolling up or down (mostly up)

in order to conserve moisture.

- brown leaf edges

- looks alot like nutrient burn, except it occurs only at the

tops of the plants closest to the light.


Too much light: What your leaves are showing you...


- leaves bleached out, destroys chlorophyll as opposed to

causing leaf cupping (often goes hand-in-hand with high

heat for indoor growers)


Over-fertilizing: What your leaves are showing you...


- leaf cupping or leaf margin rolling

- leaf margin burn

- leaf tip curl/burn

- hard, crispy feel

- harsh serrated look


Peace :P

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Overferted plants will also turn dark green, as they are overproducing chlorophyll initially, and the very tips of the leaflets will drop, just a cm or so, and only for a day or a few hours at least, but it will give you that quick warning that overferting is a problem. :P


That's a great post mate, you should consider taking some pics of these effects and posting them in the growfaq. :P

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... as it goes the leaves are a vital source of the plants life

and health. Those babies breathe and do a lot more. So thought

I would look into some of the basics..... some of the process of

what goes on with those leaves. ;)


One of the necessaries, Transpiration is the process whereby a plant loses water, primarily through leaf stomata . Stomatal openings, the route for entry of CO2 into the leaf, usually comprise less than 1% of the epidermal surface. The need for very efficient diffusional uptake of CO2 to support a reasonable photosynthetic rate by leaves creates their most serious problem, the evaporative loss of water, transpiration.


Transpiration uses about 90% of the water that enters the plant through the roots. The other 10% of the water is used in chemical reactions and in plant tissues. It is necessary for mineral transport from the soil to the plant for the cooling of the plant through evaporation, to move sugars and plant chemicals, and for the maintenance of turgor pressure.


The amount of water lost from the plant depends on several environmental factors such as temperature, humidity and wind or air movement. An increase in temperature or air movement decreases relative humidity and causes the guard cells in the leaf to shrink, opening the stomata and increasing the rate of transpiration.


With ref. to oxygen and moisture extremes, the primary consideration is the root environment where oxygen and moisture are inversely related.

Waterlogging (moisture saturation) caused by overwatering of the root environment results in oxygen deficiency... been said before... without oxygen, root metabolism and growth come to a standstill. Consequently, uptake of water and nutrients is restricted with subsequent wilting and nutritional deficiency symptoms occurring on the above ground portions of the plant. Drought and water logging produce many of the same symptoms on the above ground portion of the plant: The first symptoms will be chlorosis and abscission of older leaves. Under severe, continuing moisture stress wilting and necrosis will occur on tips and interveinal regions of recently expanded leaves and new growth.


Here is a pic of BC BB that has been overwatered... ths one grows next to

Black Domina, an indica dominant wide-fingered leaf plant... its leaf structure alone means the BD will transpire heavily and therefore more suited to constant watering... and lots of it lol !! But the sativa dominated BC BB has a much finer leaf structure and therefore is not able to transpire effectively when given the same watering regime as the indica

... here's a pic... stretchy/thin, placid looking, won't do a hell of a lot B)


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I have read this thread over a few times now(over two weeks or so) and either i have had too many cones(as usual) or i missed something. I water my babies every 3-4 days(in organic soil) and if they do not get water and the soil below 1-2 inches is dry, the leaves droop big time. If i water, within 4-8 hours later the leaves are standing up to the light. This is even more evident when i flush(with ph balanced h20 and potash as i am in the flower cycle) as the leaves begin to go from droopy to upright much quicker than a water/nute watering. This is a total opposite.......can somebody tell me what i missed?

PS: The symptoms appear more evident in the indica dominated plant than in the Sativa plant.

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