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Thinning, Pruning, FIM, Topping...

Discussion in 'General Marijuana Growing' started by asd3reff, May 22, 2007.


    asd3reff Well-Known Member

    I don't know 100% the difference between those techniques, but seems like all of them reffers to achieve more yeld.
    Now, i want to find out what you all growers think about these operations.
    I'm in process of growing my Skunk #1 seeds ( http://www.rollitup.org/grow-journals/8327-my-first-grow-skunk-1-a.html ), and i'm in 18 day of flowering. I've been told by a friend to cut the little top of the plant, when the plant was in veg period, and after toping once, the plant started to develop 2 new tops from that place i've just cut the single top. After those 2 new tops maturized, i did top that 2 tops again, so i have 4 main tops/plant. What do you think? Is it better to do this? Only once/plant? I have read that some straing need this kind of tehnique for better yeld, some others, topping them dosen't mean i'll get better yeld if topped.

    Please ..... react [​IMG]

    kindprincess Well-Known Member

    Thinning is the action of manipulating plant height and numbers either via cutting the plant at the stem or removing plants from the grow altogether. Naturally plants compete for light and plants that grow taller than the rest can easily prevent light from reaching other plants in the group. This is especially noticeable with unstable strains and new hybrids in which some of the population may grow more vigorously than others. The action of thinning your crop either by cutting or total removal creates a more even canopy and allows light to penetrate every top cola without some plants getting in the way of the other plants' light requirements.

    Thinning generally applies to outdoor growers, but some indoor setups such as ScrOG and SOG may also need to be thinned.

    As a cannabis grower you should aim to produce plants of relatively uniform growth. When all of your plants are approximately the same height, you can more easily achieve optimal lighting conditions. If one plant grows more vigorously than the others, you risk ending up with light gaps. For instance:
    • Distance from Plant A to light is 3 feet
    • Distance from Plant B to light is 1.5 feet
    • Distance from Plant C to light is 8 inches

    Obviously you will be wasting light, not to mention space, on this setup. The reason for uneven growth is simply that some plants tend to be more vigorous than others.* If this happens, the more vigorous plants will cause the smaller ones to receive less light. We use a process called thinning to control these vigorous plants.

    Clones, taken from the same mother, should not need to be thinned because they will all possess the same genetic makeup.The only time that clones will not grow in a uniform manner is if light dispersal is uneven. Obviously the clones that receive more light have a better rate of photosynthesis and will grow more vigorously. If all the clones are treated in the same way, they should grow uniformly.

    If you discover a vigorous plant, either cut it down to the same level as the others or remove it from the grow altogether. Do not throw away the cuttings from thinning. You can clone these cuttings into new plants!

    You may be tempted to thin the other way round, leaving the taller plants and removing the smaller ones. Recall that in cannabis growing, if you have started from seed, the taller plants are generally male and the smaller ones are female. For this reason do not give in to the temptation of removing plants before you actually identify their sex.

    Thinning your grow makes it look nicer, tidier and helps to improve your overall yield by preventing potentially good plants from being covered by weaker ones that are growing much taller. Remember that height and size have nothing to do with potency. Some plants with very long internodes tend to grow very tall, covering other plants and diverting most of their energy into vertical growth rather than bud production. This kind of competitive growth will only lead to less than optimal results.
    By the time you have finished your thinning you should have a uniform with some clones that you can use to grow more bud.

    kindprincess Well-Known Member

    Light bending occurs when a plant grows at an angle toward the light. You may have noticed plants on the perimeter of your grow area bending toward the light to try and get their share. If your plants bend too much they will eventually grow toward or even into another plant and block other plants from the light. Also, during flowering the buds will become heavy and may cause plants to fall over.

    A simple way to avoid light bending in an indoor grow environment, is to simply switch your plants around. If a plant leans too much in one direction, then move it toward the middle of the grow space or turn the plant around. It only takes a day or two for the plant to straighten. If your plants can't be easily moved, as is the case with hydroponic setups and outdoor gardens, then you may have to tie your plants so they don't bend.

    If you are growing outdoors and have a major problem with light bending you may have to cut away surrounding foliage to allow more light to reach your plants. If this is not possible, try using thread and small stakes, such as bamboo, to keep your plants upright. Remember: if your plants are bending they are trying to tell you that they need more direct light.

    Pruning is the action of manipulating the number of node regions (potential bud sites) that your plant creates and has nothing to do with the thinning process. Cutting a plant at the stem will automatically result in Hopping'. For this reason, plants that are thinned via cutting will end up growing more than one top cola. Topping is discussed in the next section. This section covers pruning to increase yield.
    By using stakes you can also control and separate branch growth after pruning.

    This plant has generated more than eight new node regions after pruning.
    Prune cuts are made using clippers held at a 45-degree angle to tbe shoot being cut. For every stem or branch that you prune, the cut area will develop two more branches.This process is natural: just look at any tree to see how the stem divides into branches which sub-bivide into more branches which divide into new shoots and leaves. Marijuana plants grow branches out from the stem. Any filling out occurs when new leaves and branches develop at the node regions. Some of these branches may develop new shoots, but these are somewhat smaller and thinner and don't support as much bud growth. If you prune your plant you can make it more like the example of the tree.

    Recall that Indica plants tend to be smaller than Sativas. If you learn to prune your plant properly you can produce small bushy Sativa plants that grow in tiny spaces. Without pruning, a Sativa plant can stretch to five feet or more.

    Keep in mind that there is a limit to how much you can prune a marijuana plant. If you prune the stem, it will split in two. You can prune both of these new stems and end up with four stems. You can try to prune each of these four stems to create eight stems, but results will depend on the strain and its genetically predetermined branching limit. You might be able to prune some of the lateral branches, but again, if the plant has reached its threshold it will not produce more branches. All strains are different in this respect.

    kindprincess Well-Known Member

    Some marijuana growers will take a pair of clippers to the top of their plant just above the last branch formation during the third or fourth week of vegetative growth. The top is removed by shearing it away at the stem. What happens next is that the main stem splits off in two or more directions, creating a V-shape at the top of your plant. The end result after flowering is two or more top colas instead of one. Now, two top colas instead of one does sound appealing and some growers have even managed to force a plant to grow more than six top colas using this method. Unfortunately this topping method of pruning doesn't always lead to better results.

    Depending on the strain and the growing environment, the 'topped' plant may produce two small top colas instead of two big ones. Also, each strain has a threshold for bud production that cannot be improved upon because it is a genetically predetermined factor. On the other hand, some plants when fully grown without topping do not reach their threshold. The strain Blueberry is a good example of this. If you grow Blueberry without topping you won't achieve maximum bud production from that plant, but if you top the Blueberry, you will. Other strains aren't so flexible and the two top colas will simply share the same volume of bud that a single cola would have produced on the same strain.

    It's advised that you keep in mind that pruning for yield using the topping method is strain-dependent and experiment carefully with this pruning method. Do this with 2 out of 10 plants in every grow. You'll find in time that during this vegetative prune you will be able to shape your plant. Plants are generally pruned three to four weeks into their vegetative cycle, but can be pruned sooner or later or more than once.

    Pruning during flowering is not advised as the plant will be forced to divert its energy from bud production into branch and leaf production. This results in a slower rate of bud growth. For optimal growth finish your pruning well before flowering.

    FIM Technique
    There is a topping method known as the FIM technique. If you push the leaves apart at the very top of the plant you should see a small bud (not flowering bud but an actually leaf bud). Use a pair of nail clippers to pinch off about 3/4 of the bud. This should result in more than two top colas being developed. In a single FIM clipping you can produce up to eight new top colas.
    The origins of this technique are humorous. As the story goes, FIM was discovered accidentally when a grower messed up a topping exercise. FIM stands for: "Fuck I Missed".

    kindprincess Well-Known Member

    Super Cropping Technique
    Another method of topping is called xSuper Cropping'. By taking a branch between your forefinger and thumb you can gently crush the branch, causing it to develop multiple branches above the crushed area. You must crush it on the correct side or risk breaking the branch. Just squeeze lightly until you feel the branch give, then let go. If it gives easily then you have crushed it on the correct side. If it is hard to crush and the branch splits then you have chosen the wrong side. Practice makes perfect with Super Cropping.

    Super Cropping should be carried out during the second or third week of vegetative growth and does stunt the plant. You should also note that plants that are Super Cropped can remain in the vegetative growth stage for twice as long as normal but the end result is a very bushy plant with multiple node regions that should all produce bud. Many growers have thrown Super Cropped plants away because they believed that the plants were not flowering in time. If you Super Crop your plants make sure that you have the patience to wait until the process is finished which — usually about four to six more weeks of vegetative growth.

    Some people prefer their plants small and wide. Fortunately for them, making cannabis bushes is a simple process. During the third week of vegetative growth prune half the plant's branches. Cannabis plants need at least 50 percent of their leaves in order to continue growing without experiencing fatal stunting problems. If you prune off more than 50 percent of their leaves, you may end up killing your plants.* Do not prune only one side of the plant; prune both sides to achieve the 50 percent. You may also prune the main top cola if you want to split it into two or more parts.

    If the prune cuts you previously made grow new branches and leaves, you may wait until the fourth or fifth week of vegetative growth and prune again, leaving 50 percent growth.

    During the seventh week of vegetative growth you'll notice that your plant has started to grow outward more than upward. Let's say you have a plant with eight shoots. That means it is four nodes high. You prune the plant and end up with 16 shoots, but the plant is still only four nodes high. Now this does not mean that you can keep doubling shoots forever. Pruning merely pushes the plant to grow all of its shoots early. If you keep pruning a plant that is four nodes high until the eighth week of vegetative growth, the greatest number of shoots you will get will be about 32. Most marijuana plants will not grow much beyond this factor, but again this is strain-dependent.

    Now each new shoot has a junction point or a node that it grew from and each node should produce bud during the flowering stages. It is possible to create a marijuana plant that droops over the sides, completely concealing its own pot. With the right strain, it is also possible to have a single plant spread over an entire 6x6 foot space using this method. Creating cannabis bushes usually requires a few additional weeks of vegetative growth.

    Training was covered in Chapter 8 in our discussion about advanced SOG and ScrOG setups. Training simply means tying down your plant's main stem so that it grows in an S-shaped pattern. You can also train your plants to bend into other shapes but the S-shape is the most common. Training is mainly used to prevent plants from reaching their natural vertical height without pruning, although you can also prune trained plants without a problem.

    Training does not stop your plants from growing to their natural height but instead promotes horizontal instead of vertical growth. You can also prune trained plants if you want but most growers just rely on the training to achieving optimal results. Training is accomplished by bending the plant over, attaching a piece of thread to the stem and securing the thread to either another part of the stem or another plant or object. By tightening the thread bit-by-bit, day-by-day, you can successfully bend your plants without causing them undo stress.

    Fishing line works very well in cannabis plant training. Some of the threading may be located very close to your lighting and heat can cause some threads to snap or even burn. Fishing line works best because it is one of the most durable and heat-resistant filaments you can buy. Make sure not to tie your line too tightly around the stem or you could end up cutting into it and causing plant stress, topping it or even killing it. People have managed to grow plants of all sorts of shapes using this method — from corkscrews to full circles. Some growers even like to grow their plants horizontally during the vegetative growth stage with just a single 90-degree bend at the base of the plant. When done correctly with the right strain, training can lead to excellent overall bud production.*
    If a stem breaks during training, simply hold it in place using a stake/stick and bind it with cheesecloth or a porous cloth bandage wrap.There are many types of plant waxes that you can buy from gardening stores to help close the wound. If you do not have a wax, applying honey to the wound also helps. Honey has healing properties that help rejuvenate plant wounds but must be carefully examined every day for fungi development on the honey-treated area. If you do find fungi development simply refer to Chapter 12 on how to solve this problem. Watch for any new growth at the break area and trim these away, because they will try to break away the upper part of the stem, effectively topping your plant. It is not uncommon to find roots trying to grow out from a damaged area although the high percentage of air outside of the break zone will prevent the roots from growing much more.

    kindprincess Well-Known Member

    sorry for the long texts, i thought this would be the best way to answer, as i'm too tired to type all that, lol.

    hope this helps!


    asd3reff Well-Known Member

    you mean .. Marijuana

    but i want to know the growers thoughts from theyr experience....

    kindprincess Well-Known Member

    imo, a combination of topping and lst will gain the highest yeild. i don't cut fan leaves in flower, they are the solar panels providing the energy for bud production.

    supercropping takes a long time to come back from, and fimming is near the same.

    i like plain ol topping and training.

    and no, i mean greg green's cannabis grow bible. same thing, yes, but might as well give credit where it's due. thanx greg!


    Cugine Well-Known Member

    How about a thank you all she did for you already?

    GoodFriend Lumberjack

    isn't blueberry one of those strains you want to top the fuck out of?
    i mean
    not too much
    but more so than most others?

    kindprincess Well-Known Member

    yes, you deff want to top bb, it produces small colas, but is not a yeild limmited strain. i top at four nodes, then top all branches again at 12''.


    fRyDaYkNiGhT420 Member

    Thanks for the info K.P!!! I tried it with my Sour Diesel and it worked great!

    Dwezelitsame Well-Known Member


    fRyDaYkNiGhT420 Member

    Mendo Afgoo does not like to be messed with AT ALL! Sour Diesel responds very well plus it grows like bamboo. M.A likes to be left alone don't over nute it. Sour Diesel you can poison and it would spit in your face and grow out the top of your tent. Heres a picture of a sour diesel under CFL.


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