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Trimming leaves for LST

C

Charybdis

Member
If I bend a plant around to keep it smaller and bushier, I'm just wondering - do you think it'd be better to trim the big leaves that are blocking light from reaching the smaller ones, or just leave them alone?

I've mostly been just trimming parts of the leaves, unless the canopy is too thick there in which case I'll remove the whole thing. I know that's going to stress the plant a bit, but it sees like it'd be worse to leave them there.

I guess I could tie / bend them around but that seems like a lot of effort for just a few leaves.
 
M

Massproducer

Member
Don't ever cut any leaves from your plant unless they are dead and diseased, even then they will usually fall off themselves. Think of the fan leaves as mini solar generator, so if you cut them off to provide more light to something with less surface area (bud leaves or shoot leaves) your plants abilty to convert light into energy will be greatly reduced. It is much better to tuck them if you must.
 
mrwags

mrwags

********* Female Seeds
ICMag Donor
Veteran
Charybdis said:
If I bend a plant around to keep it smaller and bushier, I'm just wondering - do you think it'd be better to trim the big leaves that are blocking light from reaching the smaller ones, or just leave them alone?

I've mostly been just trimming parts of the leaves, unless the canopy is too thick there in which case I'll remove the whole thing. I know that's going to stress the plant a bit, but it sees like it'd be worse to leave them there.

I guess I could tie / bend them around but that seems like a lot of effort for just a few leaves.
Click to expand...


Bending huh?




Have A Great Day
Mr.Wags
 
mrwags

mrwags

********* Female Seeds
ICMag Donor
Veteran
Massproducer said:
Don't ever cut any leaves from your plant unless they are dead and diseased, even then they will usually fall off themselves. Think of the fan leaves as mini solar generator, so if you cut them off to provide more light to something with less surface area (bud leaves or shoot leaves) your plants abilty to convert light into energy will be greatly reduced. It is much better to tuck them if you must.
Click to expand...

This is good advice BUT if you are running buckets and flood your giving your girls the food they need and removing some big sucker fans has been proven at least for me to be beneficial.


Wags
 
M

Massproducer

Member
I guess I just follow a different mantra... I don't really consider fans ever to be suckers or sinks of energy, I consider them always to be stores. The problem I have is even when providing an optimal nute regime, light is always going to be converted using the nutes into usable energy and the excess energy will be stored in the leaves, thats why when we see any type of mobile nute deficiency it is going to show in the older fans first as the plant breaks into its stores. So for me it just doesn't seem like ever a good choicce in my situation... I do however love to lollipop my plants, but even when I lollipop, I still keep the lower fans, it just seems to me like throwing out a perfectly fine battery, to replace it with a weaker one.
 
D

darrmann

Member
dont beleive everything you here. I do heavy pruning trimming at 2 days into flower, 2 weeks later then 2 weeks later trim off all big leaves hiding buds. It doesnt hurt them or slow them down. use some superthrive and you will see no stress, or very little. I do this so i end up with all big colas and end buds .less to trim and no popcorn. my grow is 2 weeks in veg and 60 days in flower. if it hurt it would i get this quick of turnover? NO
 
M

Massproducer

Member
Cutting off all of the fan leaves has no effect on stress or yield??? You may want to rethink that. Pruning is thinning out sucker branches, not cutting off the plants food storgae source???

Quick turnover??? Once again lollipopping is not cutting fan leaves, it is pruning the lower branches so that all of the energy is put into flowering sites that receive more light. Fan leaves are not sinks they are stores, and YES cutting them off is bad
 
jm420

jm420

Active member
Veteran
I cut all fans bigger than a half dollar on my scrogs when training with no ill effect
 
GrnMtnGrwr

GrnMtnGrwr

Active member
Veteran
Massproducer said:
Cutting off all of the fan leaves has no effect on stress or yield??? You may want to rethink that. Pruning is thinning out sucker branches, not cutting off the plants food storgae source???
Click to expand...

The only actual comparison I have seen done showed that removing all fan leaves a few weeks into flower was actually beneficial... I'm not going to change the way I grow based on one person's anecdotal evidence, but I'm certainly not going to discredit it without further investigation.

Personally, I only remove fan leaves if they come off with a very light tug.
 
M

Massproducer

Member
Please show me ANY information showing any benefit to cutting fan leaves??? Now during veg your plant will just regenerate the leaves lost, but during flowering the plant stops pruducing leaves and puts its energy into growing buds using the infastructure that is already present.

Back in the OverGrow days there was a debate and it turned into a rather nice post, here are some excerts:

HOW DO FAN LEAVES FUNCTION
The large fan leaves have a definite function in the growth and development of cannabis. Large leaves serve as photosynthetic factories for the production of sugars and other necessary growth substances. Most cannabis plants begin to lose their larger leaves when they enter the flowering stage and this trend continues on until senescence (death of the plant).

Fan leaves account for the greatest area for the reception of photons on a plant, thus they account for the majority of photosynthesis which occurs within a plant. Cells in the plant's leaves, called chloroplasts, contain a green pigment called chlorophyll which interacts with sunlight to split the water in the plant into its basic components. Leaves only absorb about 15% of the solar energy that hits them, the other 85% passes through-- but they reflect all the green light, which means it looks darker below the leaf to a human than it does to the plant because our eyes are most sensitive to the green spectrum (Shipperke, 03.15.2002).

Photosynthesis occurs in all green parts of plants. The process has two stages, the light reactions and the Calvin cycle, that convert water and carbon dioxide into sugar and oxygen. These sugars are later used to power all the processes in the plant, including the synthesis of THC and other cannabinoids (Shipperke, 04.02.2002; Ca, 03.13.2002). Fan leaves possess the greatest number of stomata, which are small pores or valves on the underside of the leaf which water vapor and carbon dioxide diffuse during transpiration and photosynthesis (carbon fixation). Carbon dioxide first enters the leaf through the stomata and combines with the stored energy in the chloroplasts through a chemical reaction (the Calvin cycle) to produce a simple sugar. This sugar is unloaded into the tissues and transported through tubes in the leaf to supply the synthesized food to other plant parts such as growing or respiring tissues like young leaves, roots, and flowers of the plant. meristems (UK Tricky Knome, 03.14.2002).

Removal of fan leaves will not only slow growth, but it will also hinder the plants ability to rid itself of toxic gases, and also hinder the regulation of the plants temperature via stomata. Changes in the plants chemical metabolism caused by fan leave removal causes the plant to work overtime to rid ‘toxins’ with less leaves, as a result the pant may allocate more growth hormones into growing more leaves to make up for what has been lost(Equator, 03.15.2002). Removing large amounts of fan leaves may also interfere with the metabolic balance of the plant. Leaf removal may also cause sex reversal resulting from a metabolic imbalance.

There is a relationship regarding the amount of carbohydrates a leaf produces and CO2 intake relative to outside forces. When you have a situation whereby the leaf is no longer productive for the plant for whatever reason that may be - low light, old age, disease, insect attack etc, the plant will discard it. (Thunderbunny as citied, by Nietzsche, 03.13.2002.

Plants have two different kinds of vessels in their stems to move stuff around, xylem and phloem. Xylem runs from the roots up the stem carrying water and nutrients. Phloem runs both up and down to move sugars hormones, proteins, etc but mostly sugars. Each part of the plant can be either a sugar source or a sugar sink (Shipperke, 03.15.2002). Phloem moves from sources (areas of supply) to sinks (areas of metabolism or storage). Granted that the flowers can produce some photosynthate, but they are no where near as effective as fan leaves (resin glands significantly reduce light to the tissue they are found on). Flowers are sink tissues, leaves are source tissues. Sinks do not produce enough photosynthate, and are importers. Sources give photosynthate to sinks in closest proximity. Upper leaves bring sucrose to shoot apical meristem and young leaves while lower leaves bring goodies to roots (UK Tricky Knome, 03.17.2002). Remove the source and the sink will be affected (Diels Alder, 03.15.2002).

The leaves at the top of a plant tend to supply the top growing shoots. The leaves at the bottom of the plant tend to supply the roots. The middle leaves can go either way as the demand changes. During flowering and fruiting, only the very bottom leaves supply the roots and the rest of the leaves try to get as much energy as possible to the flowers of fruits. For this reason, the more leaves are unshaded and in good light, the more chance the plant has of creating extra storage of energy that will ultimately go into yield (Leaf, 03.13.2002). However Jeast (03.13.02) believes that the rich green leaves emerging from the bud are a sufficient energy source of solar energy for the plant's floral development. Therefore the old fan leaves are once again rendered useless and only drain energy from the developing part of the plant (Jeast, 03.13.02).

Fan leaves store mobile nutrients, these stored nutrients are essential in the later stages of flowering. When flushing a plant the fan leaves will lose their color quickly. This is because the nutrients are being mobilized to the atypical meristem (grow tip, bud site). Draining your fan leaves with a flushing period will increase floral development (Ca, 13.03.2002). Fan leaves therefore serve as a nutrient deficiency buffer zone for the plant (Higstar, 03.13.2002).
Nutrient burn usually causes bottom leaves begin to die however DaGnome (03.15.2002) observed that if you do not remove the leaves then they will absorb damage as premature removal generally results in more leaf loss. However if growing hydroponically under ideal conditions it could be argued that fan leaves serve as a nutrient buffer is a moot point.

To Increase Lower Bud Development
Light efficiency decreases with distance. The inverse squared light rule states that illuminance is inversely proportionate to the square of the distance from the light source.
Removing the largest area of photosynthesis that is closest to the light source simply to benefit smaller leaves growing out of the but sites that are further away is not logical when growing indoors"(Smokinrav, 03.15.2002). Cultivating outdoors under the sun, the fan leaves don't create nearly as much shade as they do indoors (~shabang~, 03.13.2002). This is consistent with the inverse squared light rule; the sun is 149,597,890 km away so a few feet has no real effect on intensity. This suggests that a trimming benefit could be achieved outdoors as opposed to indoors however leaves only absorb about 15% of the solar energy that hits them, the other 85% passes through except for green light which is reflected, therefore removal of fan leaves would only provide a 15% increase light transmission outdoors (Shipperke, 03.15.2002).

Jeast (03.12.2002) removes fan leaves that are yellowing or starting to yellow (these are usually on the lower stems) and also mid-stem fan leaves that are shading buds. He always try to retain the upper 2 - 3 sets of fan leaves indoors as he believe they are the ones that are truly "working". The concept of the upper fan leaves doing all the work is consistent with effect of the inverse square rule on lighting intensity indoors and the flow on effect for photosynthesis. In support for trimming HyGradeChronic (03.25.2002) states selective trimming benefits lower floral development, allowing the buds to fill out and tighten up better. However he does mention that humidity must be kept to a minimum as leftover stems from the leaf can develop mould unless kept at optimum humidity. Another flow on effect to leaf trimming mentioned by HydradeChronic is that it takes seven to ten days longer for floral development to finish, but the resulting florescence is at it’s peak from top to bottom.

An alternative to trimming to increase light to lower floral clusters is to use a light mover on a single plant the results are better thanks to the better penetration of light at different angles. Even simple under lighting and side lighting works well to counter fan leaves by adding extra light where it would not normally get (Vapour, 03/13.2002).
 
D

darrmann

Member
cutting the growing shoots and removing some leaves does NOT hurt the plant. In nature plants are well adapted too loss of parts do to wind,predators etc. When leaves are damaged or lost the plant just plugs the wound it doesnt grow a new leave. new leaves are continually being formed from the growing shoots. pruning simply allows the plant to develop its branches earlier. the branchespresent more area to gather light and, hence can grow to fill a larger space. The most important thing about this is not to overdo it.
Everyone has experienced his own technique, dont be so quick to put others down about theres. Ever here of the mj grow bible. got this info directly from there.
 
D

darrmann

Member
Massproducer said:
Please show me ANY information showing any benefit to cutting fan leaves??? Now during veg your plant will just regenerate the leaves lost, but during flowering the plant stops pruducing leaves and puts its energy into growing buds using the infastructure that is already present.

Back in the OverGrow days there was a debate and it turned into a rather nice post, here are some excerts:

HOW DO FAN LEAVES FUNCTION
The large fan leaves have a definite function in the growth and development of cannabis. Large leaves serve as photosynthetic factories for the production of sugars and other necessary growth substances. Most cannabis plants begin to lose their larger leaves when they enter the flowering stage and this trend continues on until senescence (death of the plant).

Fan leaves account for the greatest area for the reception of photons on a plant, thus they account for the majority of photosynthesis which occurs within a plant. Cells in the plant's leaves, called chloroplasts, contain a green pigment called chlorophyll which interacts with sunlight to split the water in the plant into its basic components. Leaves only absorb about 15% of the solar energy that hits them, the other 85% passes through-- but they reflect all the green light, which means it looks darker below the leaf to a human than it does to the plant because our eyes are most sensitive to the green spectrum (Shipperke, 03.15.2002).

Photosynthesis occurs in all green parts of plants. The process has two stages, the light reactions and the Calvin cycle, that convert water and carbon dioxide into sugar and oxygen. These sugars are later used to power all the processes in the plant, including the synthesis of THC and other cannabinoids (Shipperke, 04.02.2002; Ca, 03.13.2002). Fan leaves possess the greatest number of stomata, which are small pores or valves on the underside of the leaf which water vapor and carbon dioxide diffuse during transpiration and photosynthesis (carbon fixation). Carbon dioxide first enters the leaf through the stomata and combines with the stored energy in the chloroplasts through a chemical reaction (the Calvin cycle) to produce a simple sugar. This sugar is unloaded into the tissues and transported through tubes in the leaf to supply the synthesized food to other plant parts such as growing or respiring tissues like young leaves, roots, and flowers of the plant. meristems (UK Tricky Knome, 03.14.2002).

Removal of fan leaves will not only slow growth, but it will also hinder the plants ability to rid itself of toxic gases, and also hinder the regulation of the plants temperature via stomata. Changes in the plants chemical metabolism caused by fan leave removal causes the plant to work overtime to rid ‘toxins’ with less leaves, as a result the pant may allocate more growth hormones into growing more leaves to make up for what has been lost(Equator, 03.15.2002). Removing large amounts of fan leaves may also interfere with the metabolic balance of the plant. Leaf removal may also cause sex reversal resulting from a metabolic imbalance.

There is a relationship regarding the amount of carbohydrates a leaf produces and CO2 intake relative to outside forces. When you have a situation whereby the leaf is no longer productive for the plant for whatever reason that may be - low light, old age, disease, insect attack etc, the plant will discard it. (Thunderbunny as citied, by Nietzsche, 03.13.2002.

Plants have two different kinds of vessels in their stems to move stuff around, xylem and phloem. Xylem runs from the roots up the stem carrying water and nutrients. Phloem runs both up and down to move sugars hormones, proteins, etc but mostly sugars. Each part of the plant can be either a sugar source or a sugar sink (Shipperke, 03.15.2002). Phloem moves from sources (areas of supply) to sinks (areas of metabolism or storage). Granted that the flowers can produce some photosynthate, but they are no where near as effective as fan leaves (resin glands significantly reduce light to the tissue they are found on). Flowers are sink tissues, leaves are source tissues. Sinks do not produce enough photosynthate, and are importers. Sources give photosynthate to sinks in closest proximity. Upper leaves bring sucrose to shoot apical meristem and young leaves while lower leaves bring goodies to roots (UK Tricky Knome, 03.17.2002). Remove the source and the sink will be affected (Diels Alder, 03.15.2002).

The leaves at the top of a plant tend to supply the top growing shoots. The leaves at the bottom of the plant tend to supply the roots. The middle leaves can go either way as the demand changes. During flowering and fruiting, only the very bottom leaves supply the roots and the rest of the leaves try to get as much energy as possible to the flowers of fruits. For this reason, the more leaves are unshaded and in good light, the more chance the plant has of creating extra storage of energy that will ultimately go into yield (Leaf, 03.13.2002). However Jeast (03.13.02) believes that the rich green leaves emerging from the bud are a sufficient energy source of solar energy for the plant's floral development. Therefore the old fan leaves are once again rendered useless and only drain energy from the developing part of the plant (Jeast, 03.13.02).

Fan leaves store mobile nutrients, these stored nutrients are essential in the later stages of flowering. When flushing a plant the fan leaves will lose their color quickly. This is because the nutrients are being mobilized to the atypical meristem (grow tip, bud site). Draining your fan leaves with a flushing period will increase floral development (Ca, 13.03.2002). Fan leaves therefore serve as a nutrient deficiency buffer zone for the plant (Higstar, 03.13.2002).
Nutrient burn usually causes bottom leaves begin to die however DaGnome (03.15.2002) observed that if you do not remove the leaves then they will absorb damage as premature removal generally results in more leaf loss. However if growing hydroponically under ideal conditions it could be argued that fan leaves serve as a nutrient buffer is a moot point.

To Increase Lower Bud Development
Light efficiency decreases with distance. The inverse squared light rule states that illuminance is inversely proportionate to the square of the distance from the light source.
Removing the largest area of photosynthesis that is closest to the light source simply to benefit smaller leaves growing out of the but sites that are further away is not logical when growing indoors"(Smokinrav, 03.15.2002). Cultivating outdoors under the sun, the fan leaves don't create nearly as much shade as they do indoors (~shabang~, 03.13.2002). This is consistent with the inverse squared light rule; the sun is 149,597,890 km away so a few feet has no real effect on intensity. This suggests that a trimming benefit could be achieved outdoors as opposed to indoors however leaves only absorb about 15% of the solar energy that hits them, the other 85% passes through except for green light which is reflected, therefore removal of fan leaves would only provide a 15% increase light transmission outdoors (Shipperke, 03.15.2002).

Jeast (03.12.2002) removes fan leaves that are yellowing or starting to yellow (these are usually on the lower stems) and also mid-stem fan leaves that are shading buds. He always try to retain the upper 2 - 3 sets of fan leaves indoors as he believe they are the ones that are truly "working". The concept of the upper fan leaves doing all the work is consistent with effect of the inverse square rule on lighting intensity indoors and the flow on effect for photosynthesis. In support for trimming HyGradeChronic (03.25.2002) states selective trimming benefits lower floral development, allowing the buds to fill out and tighten up better. However he does mention that humidity must be kept to a minimum as leftover stems from the leaf can develop mould unless kept at optimum humidity. Another flow on effect to leaf trimming mentioned by HydradeChronic is that it takes seven to ten days longer for floral development to finish, but the resulting florescence is at it’s peak from top to bottom.

An alternative to trimming to increase light to lower floral clusters is to use a light mover on a single plant the results are better thanks to the better penetration of light at different angles. Even simple under lighting and side lighting works well to counter fan leaves by adding extra light where it would not normally get (Vapour, 03/13.2002).
Click to expand...

have you ever pruned back your plants? or are you just talking about what you've read? because my plants are in flower, and as soon as I pruned my plants less then 4 days later had leaves as big as i had just trimmed. Everyone has there own techniques and "best way" to do it. dont knock someone for having a different opinion or actual proof in there own grow.
 
D

darrmann

Member
Im not sure what he"s arguing about but below is in his own reply that its not alright. This is telling you to do it Jeast (03.12.2002) removes fan leaves that are yellowing or starting to yellow (these are usually on the lower stems) and also mid-stem fan leaves that are shading buds. He always try to retain the upper 2 - 3 sets of fan leaves indoors as he believe they are the ones that are truly "working". The concept of the upper fan leaves doing all the work is consistent with effect of the inverse square rule on lighting intensity indoors and the flow on effect for photosynthesis. In support for trimming HyGradeChronic (03.25.2002) states selective trimming benefits lower floral development, allowing the buds to fill out and tighten up better. However he does mention that humidity must be kept to a minimum as leftover stems from the leaf can develop mould unless kept at optimum humidity. Another flow on effect to leaf trimming mentioned by HydradeChronic is that it takes seven to ten days longer for floral development to finish, but the resulting florescence is at it’s peak from top to bottom.
 
High Country

High Country

Give me a Kenworth truck, an 18 speed box and I'll
Veteran
I think of the fan leaves as the engine room of the plant. This is where all the photosynthesis takes place.

I only remove the leaves when they start to die off deep into the flowering cycle.

I ensure good light penetration by putting the clones straight onto a 12/12 light cycle, single cola, SOG style.

They finish at about 2 1/2' and light from a 600W globe penetrates to the base of the plant.

That's just my humble opinion.

Cheers.
 
M

Massproducer

Member
Don't take things out of context... What it says is that he removes damaged leaves that are starting to yellow, meaning they are being eaten by the plants and not photosynthesising any long, plus the Plant has eaten all of the nutes stored in the leaves, that is why it is yellow. LMAO

There is a difference between do no harm and thrive. I have provided you with information based on science... Where is yours??? Yes as I stated I screen and lollipop all of my plants. Which means that I cut off all of the lower branches that will not reach the canopy, as they will be sinks for energy, and will never be worth while buds regardless of me cutting a direct window to the lower shoot because of the LAW of Diminishing Light, which states that artificial light loses if efficiency exponentially the farther away for the source you move. So at 2 feet away from the light source your plant only actually sees half of the light emitted, at 4 feet your plant sees about 1/8th of the light, and so on... So trimming leaves that see more light and have a larger surface area to absorb and store light makes no sense whatsoever.

They were talking about trimming everything underneath the canopy to increase the energy given to lower to the upper half of the plant beacuse nothing remains under the canopy, not cutting the fan leaves so that lower branches get more light, which is what this thread was about.

There is no technique of cutting off fan leaves to increase growth, that is an oxymoron

darrmann said:
Im not sure what he"s arguing about but below is in his own reply that its not alright. This is telling you to do it Jeast (03.12.2002) removes fan leaves that are yellowing or starting to yellow (these are usually on the lower stems) and also mid-stem fan leaves that are shading buds. He always try to retain the upper 2 - 3 sets of fan leaves indoors as he believe they are the ones that are truly "working". The concept of the upper fan leaves doing all the work is consistent with effect of the inverse square rule on lighting intensity indoors and the flow on effect for photosynthesis. In support for trimming HyGradeChronic (03.25.2002) states selective trimming benefits lower floral development, allowing the buds to fill out and tighten up better. However he does mention that humidity must be kept to a minimum as leftover stems from the leaf can develop mould unless kept at optimum humidity. Another flow on effect to leaf trimming mentioned by HydradeChronic is that it takes seven to ten days longer for floral development to finish, but the resulting florescence is at it’s peak from top to bottom.
Click to expand...
 
dubwise

dubwise

in the thick of it
Veteran
Charybdis said:
If I bend a plant around to keep it smaller and bushier, I'm just wondering - do you think it'd be better to trim the big leaves that are blocking light from reaching the smaller ones, or just leave them alone?

I've mostly been just trimming parts of the leaves, unless the canopy is too thick there in which case I'll remove the whole thing. I know that's going to stress the plant a bit, but it sees like it'd be worse to leave them there.

I guess I could tie / bend them around but that seems like a lot of effort for just a few leaves.
Click to expand...

IMHO-When I've LST'd a plant, I did not need to cut anything away, the plant was gently bent in to shape and tied up and the leaves found a new path on their own toward the light. If I do want to cut something... I usually cut the bottom smaller growth out all together and focus on my tops when I've got a plant in LST. If you must cut, she's forgiving so try out what works best to get your plant in the "sweet zone" of light and go from there. Good luck!
 
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