Professional Marijuana Grower July-August 2019 Issue | Page 20

tunately, many of these growers never realize that their plants aren’t operating at full potential. When to Flush During the Grow Cycle There are basically two times when a grower may want to flush his or her growing medium during the grow cycle. The number one reason to flush during the grow cycle is if there are any signs of toxicity or nutrient deficiencies. If a gardener is experiencing a potential nutrient deficiency, but has been feeding a well-rounded fertilizer, more than likely a mineral build up is causing the problem and a flush should be imple- mented to rectify the problem. The other time to poten- tially flush the plants is during a transitional period. In other words, when changing fertilizers from vegetative to flowering or right before the fertilizer regimen is changed during the later stages of flowering. Flushing during transitional periods helps remove minerals that may not be appropriate for the particular stage of growth the plants are entering. For example, the high nitrogen fertilizers used during a cannabis plant’s veg- etative growth should be removed prior to initiating the flowering stage. Too much nitrogen during the flower- ing stage will lead to undeveloped flowers and reduced yields and/or quality. How to Flush Whether doing a final flush prior to harvest or a flush during the grow cycle, there are different techniques a cannabis grower can use to flush his or her medium. The type of medium is generally the determining factor as to which technique will be the best. For example, in deep water culture or aeroponic hydroponic systems, flushing is as simple as changing out the nutrient reser- voir with fresh nutrient solution. These particular types of systems do not have an actual medium that comes in direct contact with the nutrient solution and, therefore, cannot hold on to minerals in the same way that other media can. Soil, stonewool, coco coir, or other soilless media can physically hold on to minerals. In order to flush these types of media, a solution must be poured MULTIPURPOSE GREENHOUSE DISINFECTANT & DISEASE CONTROL • Disinfect pots, trays, benches, tools, etc. • Algae control on walkways, pots, evaporative coolers, soil • Spray on plants to control bacterial, viral and fungal disease • Excellent wetting agent through the medium to “pull” out the excess minerals. This can be done with a specific flushing product or a diluted fertilizer. As previously stated, if using a flushing product, make sure to follow the directions from the manufacturer. As an alternative to a flushing product, a cannabis grower can dilute the fertilizer regimen he or she is using to 1/8 the normal concentration and pour this solution through the medium. Alike molecules tend to bond to each other, which is why a diluted fertilizer works to pull the minerals out of the medium. When flushing with a diluted fertilizer, cannabis growers should aim for a high volume of solution to run through the medium. Anywhere from five to ten times the normal amount fed to the plants is a good starting point. This is especially true with soil, which tends to hold on to excess minerals the most. Flushing for Organics Organic fertilizers rely on microorganisms to break down organic matter into a usable form for the plants. Because of this method of mineral delivery, flushing in an organic garden is not as imperative as in a garden fed with a chemical mineral fertilizer. When cannabis plants are fed a chemical mineral fertilizer, the micro- organisms in the soil are bypassed and the plants can easily end up storing excess minerals in their tissue. With organics, the plants are not fed directly, but, instead, the microorganisms in the medium are fed organic matter which they break down into elements that are absorbed by the plants. Plants fed organic fertilizers tend to take what they need and will end up with less excess minerals in the plant’s tissue. Many organic cannabis gardeners continue to feed the plants up to the day of harvest. Organic or not, I recommend withholding all nutrients for the last week or two prior to harvesting. Cannabis horticulturists who understand how, when, and why to flush are more likely to have healthier crops and a higher quality finished product. Flushing during a cannabis plant’s life cycle could, in some cases, mean the difference between the success and failure of the crop. Flushing during the critical transitional stages will allow the cannabis plants to initiate flowers more quickly, which, down the road, can contribute to an in- creased yield. If a cannabis grower truly values healthy plants and producing the highest quality product pos- sible, then flushing the plants just prior to harvesting is essential. Flushing cannabis plants right before harvest is the best way to ensure the harvested flowers will not only be safe to consume, but will also retain their natu- ral flavors, odors, and potency. PMG • Cost effective, pleasant odor and environmentally friendly MARIL PRODUCTS, INC. 15421 Red Hill Ave. • Suite D • Tustin, CA 92780 USA 714-544-7711 • 800-546-7711 • www.physan.com 20 • Professional Marijuana Grower Eric Hopper is Editor in Chief for NUGL Media Group. He can be contacted at [email protected]. July/August 2019