If chemical fertilizers are used I believe flushing is a must. When growing organically I do not believe it too be a must but I still do believe it will result in an ever better tasting and smoother smoke .... but a sound argument can be made against that. It basically is a nature will take her course no matter what we do.
Do you need to flush or not? Pt. 1
One controversial aspect of Marijuana growth is "flushing". In regards to this discussion I think we need to clearly define what exactly it is we're talking about. Flushing for our purposes typically implies using an unusually large amount of pH balanced water to essentially leach salt and/or nutrients from our medium, and hence our plant. Simply feeding your plant pH balanced water is not quite the same thing - allowing for excessive run-off, prior to harvest, is the real purpose. Many of us flush. Why? Obviously, because we like the results - cleaner smoke, a more natural flavor and healthier product are just some of our reasons - or excuses. What we need to do to is to develop a better understanding of what exactly the "flush" is accomplishing and really how healthy for the plant and our selves it may be. In researching this, one conclusion after the next led me to believe in it's irrelevance and then again, it's importance.
First I looked into how many regular crops are "flushed" prior to harvest. The practice is really not adhered to. I primarily looked into Tobacco crops as that plant also, will be smoked. Very little information showed up, in fact most commercial farmers will apply only the nutrients and water needed, never any extra - it's a matter of economics. Excessive run-off in those conditions means food is washing away. It should have been more obvious to me initially, that tobacco companies are absolutely not worried abut removing excessive any thing from they're product. I did find and interesting comparative study however, and will link the post at the end. In any case, It's important to understand what things we are trying to remove from the our plant. Most of us agree that primarily slowing photosynthesis, and hence eliminating chlorophyll will make our smoke taste smoother. This is where things get confusing however, or I should say they become clear.
Lets consider some general science to the plant we are growing, and then discuss our influences over it. Marijuana is an Annual, this means in it's natural environment it will grow to maturity and if pollinated, will drop seed in a single season. Next season, it's seed will guarantee reproduction. Outdoors this process occurs year after year given environmental conditions are typical. We all see this occur under the sun, season after season and typically never really consider why and how this can have influence over our indoor Marijuana crop. All Annuals experience an internal process triggered from what most believe to be primarily light cycle, called Senescence. An Annual plant will begin to concentrate it's efforts into producing fruits and/or seed to insure future generations. This process is typically hormonally induced and begins when the light cycle begins to diminish. Eventually, under conditions related to senescence, the plant will slow photosynthesis on it's own and naturally draw nutrients from fan leaves to relocate energy into reproduction. So consider that out doors, under natural light deprivation, Annual plants will essentially "flush" themselves, basically to death, all to develop healthy seed. It is a natural and predictable process. I had some very interesting conversation regarding this subject and was given a basic example of how plants choose they're time to go, regardless if we flush or not - under some conditions. If we had some heavily amended soil outdoors in our garden. We could easily grow multiple types of veggies and plants including Marijuana in the same garden, in the same soil. Even with the different nutrient demands of the various plants they all thrive given the right food is in the soil. This is a perfect example of a plant choosing which and what nutrients it absorbs and when it absorbs them. This happens because the plant is reacting with the soil microbiology. Microbes like bacteria and fungi build relationships with plants and essentially trade nutrients for carb rich substances and various fluids assisting in microbial growth. It's known as a symbiotic relationship, one relies on the other. So if an Annual plant, interacting with soil life, chooses it's own uptake gathered conditions are correct, how much influence can we really have? The answer is easy, we have no influence in some conditions. Using some grow methods however, we have all the influence. Remember, adhering to strictly a plants natural and proven method of finishing it's life cycle is important to understand, however, Marijuana itself has no intention of being smoked. Adding this unnatural process of flushing may result in a product more friendly to our purpose. We don't wait for apples to fall on the ground, we pick and eat them before the plant has given them to us. Many agricultural crops, grown under the strictest organic conditions are altered in the natural process to better provide us with product. Product that at times is tastier, more nutritious and generally healthier with human intervention.
Microbial life binds to organic matter. Under organic conditions - real bio-dynamic organics where all organic matter is added to soil prior to growing a plant, and microbial life is our priority. Flushing seems irrelevant. I said it. Irrelevant. We are relying on microbial interaction and our feedings consist of typically water only in the first place. In fact, rich, organic soil will filter your water - run-off will literally be cleaner than the water added. I've flushed enormous amounts of water through organic soil, and indeed, I washed away soil life and plants showed stress. But stress was exactly it. I was now eliminated the plants known form of absorption. Yes this resulted in yellowing leaves, and the results indeed mimic senescence but what was I really accomplishing. I was forcing the plant to look to itself for food before her time, and really starving her to maturity rather than allowing her to naturally mature under normal conditions. The eventual results hypothetically should be the same. I starve the plant through excessive watering, or the plant starves itself through Senescence. With that theory in mind under strict organic conditions, in my opinion it is always wise to let the plant follow it's natural cycle when ever possible. Indoors, in controlled environments, when we switch our light cycle to 12/12 senescence essentially is triggered to begin. We do have some control however, seeding for example, is usually avoided. A plant will prolong growth when pollination does not occur. We can add growth hormones, things like sea weed and algae based additives which contain numerous growth hormones such as cytotoxins and gibberellins. Both contribute to extended growth and delayed Senescence. Many tricks of the trade can lead to larger yields and at times and extended harvest times. It is a soil food web that feeds our plants, a symbiotic environment that naturally harmonizes. Destroying the harmony, disrupting the balance can indeed induce stress and typical deficiencies, but regardless of what we add or take away, under organic conditions, the plant and it's relationship with microbial life dictate when maturity has arrived and when she is ready for harvest - not a flood of water. It should be noted that there can be exceptions to the above, such as smaller pots for example.
. 'Poor' growers are not the only people who flush, many experts do. You take the food away because, like all live organisms, the plant itself stores enough food to survive and grow and continue to produce flowers and resin. At this stage in your grow, your should not be worried about your buds swelling up; as this would imply over-maturity; you should be worried about resin production. Watering a plant stresses it out...how does this make any sense have you ever heard of rain? Obviously gushing water through your plants roots will harm it and its growing medium, but a controlled heavy watering shouldn't stress your plants. No matter how much you flush you won't flush out ALL the nutrients in the medium, you may be able to get out most of the usable stuff for the plant but never every necessary nutrient. I don't think flushing is quite the monster your making it.
