Marijuana plant regeneration after harvest
It is possible to harvest marijuana plants and then rejuvenate them vegetatively for a second nd and even third harvest. A second harvest can be realized in as little as 6 to 8 weeks. Since the marijuana plant's stalk, and roots are already formed, the marijuana plant can produce a second, even third harvest of buds in a little more than half the time of the original harvest. When harvesting, take off the top 1/3rd of the marijuana plant. Leave most healthy fan leaves in the middle of the marijuana plant, cutting buds off branches carefully. On the lower 1/3rd of the marijuana plant, take off end flowers, but leave several small flowers on each branch. These will be the part of the marijuana plant that is regenerated. The more buds you leave on the cannabis plant, the faster it will regenerate. Feed the marijuana plant some high nitrogen plant food immediately after harvest. When you intend to regenerate a marijuana plant, make sure it never gets too starved for nitrogen [N] as it is maturing, or all the sun leaves will fall off, and your plant will not have enough leaves to live after being harvested. Harvested marijuana plants can come inside for rejuvenation under continuous light or are left outside in summer to rejuvenate in the natural long days.
It will take 7 to 14 days to see signs of new growth when regenerating a marijuana plant. As stated before, and in contrast to normal growth patterns, lower branches will be the first to sprout new vegetative growth. Allow the marijuana plant to grow a little vegetatively, then take outside again to re-flower. Or keep inside for vegetative cuttings. You now have two or three generations of marijuana plants growing, and will need more space outside. But you will now be harvesting twice as often. As often as every 30 days, since you have new clones or marijuana seedlings growing, vegetative marijuana plants ready to flower, and regenerated marijuana plants flowering too. Regenerating indoors can create problems if your plants are infected with pests. It may be best to have a separate area indoors that will not allow your marijuana plants to infect the main indoor area. An alternative to regenerating indoors is to regenerate outdoors in the summer. Just take a harvest in June, then allow the marijuana plant to regenerate by leaving some lower buds on the marijuana plant, and leaving the middle 1/3rd of the marijuana plant's leaves at harvest. Feed it nitrogen [N], and make sure it gets lots of sun. It will regenerate all summer and be quite large by fall, when it will start to flower again naturally.
Intensify growth with carbon dioxide CO²
Elevating carbon dioxide CO² levels can increase growth speed a great deal, perhaps even double it. It seems that the cannabis plant evolved in primordial times when natural CO² levels were many times what they are today. The marijuana plant uses CO² for photosynthesis to create sugars it uses to build plant tissues. Elevating the CO² level will increase the marijuana plants ability to manufacture these sugars and marijuana plant growth rate is enhanced considerably. CO² can be a pain to manufacture safely, cheaply, and/or conveniently, and is expensive to set up if you use a CO² tank system. CO² is most usable for flowering, as this is when the marijuana plant is most dense and has the hardest time circulating air around its leaves. If your strictly growing vegetatively indoors, [transferring your marijuana plants outdoors to flower], then CO² will not be a major concern unless you have a sealed greenhouse, closet or bedroom, and wish to increase yield and decrease flowering time. CO² is cheaply produced by burning Natural Gas. However, heat and Carbon Monoxide must be vented to the outside air. CO² can be obtained by buying or leasing cylinders from local welding supply houses. If asked, you can say you have an old mig welder at home and need to patch up the lawnmower [trailer, car, etc.] For a small closet, one tank could last 2 months, but it depends on how much is released, how often the room is vented, hours of light cycle, room leaks, enrichment levels and dispersion methods.
This method may be overkill for your small closet. It is generally viewed as good to have a small constant flow of CO² over the marijuana plants at all times the lights are on, dispersed directly over the marijuana plants during the time exhaust fans are off. Opportunities exist to conserve CO² , but this can cost money. When the light is off you don't need CO² , so during flowering, you will use half as much if you have the CO² solenoid setup to your light timer. When the fan is on for venting, CO² is shut off as well. This may be up to half the time the light is on, so this will affect the marijuana plants exposure times and amount of gas actually dispensed. Environmentally, using bottled gas is better, since manufacturing it adds to greenhouse effect, and bottled CO² is captured as part of the manufacturing process of many materials, and then recycled. Fermenting, CO² generators, and baking soda and vinegar methods all generate new CO² and add to greenhouse effect. CO² generation from fermentation and generators is possible. A simple CO² generator would be a propane heater. This will work well, as long as the gases can be vented to the grow area, and a fan is used to keep the hot CO² [that will rise] circulating and available below at the marijuana plants level. Fire and exhaust venting of the heat are issues as well. A room that must be vented 50% of the time to rid the environment of heat from a lamp and heater will not receive as much CO² as a room that can be kept unvented for hours at a time. However, CO² generators are the only way to go for large operations.
Fermentation or vinegar over baking soda will work if you don't have many vent cycles, but if you have enough heat to make constant or regular venting necessary, these methods become impractical. Just pour the vinegar on baking soda and close the door, [you lose your CO² as soon as the vent comes on]. This method leaves a great deal to be desired, since it is not easy to regulate automatically, and requires daily attention. It is possible however, to create CO² by fermentation, let the wine turn to vinegar, and pour this on baking soda. It's the most cost-effective setup for most marijuana closet growers. In fermentation, yeast is constantly killing itself; it takes a lot of space. You need a big bin to constantly keep adding water to, so that the alcohol levels will not rise high enough to kill the yeast. Sugar is used quickly this way, and a 10 pound | 5 kg sack lasts about 2 to 3 weeks. This is also difficult to gauge what is happening as far as amounts actually released. A tube out the top going into a jar of water will bubble and demonstrate the amount of CO² being produced. Try sodium bicarbonate mixed with vinegar, 1 teaspoon [5 ml] this will gush up all frothy as it releases CO² . Do it just before you close the door on your marijuana plants. A much cheaper way to provide CO² is 2 ounces | 55 grams sugar in 0.5 gallons | 2 liters of water in a bottle [sterilized first with bleach and water, then rinsed], plus a few cc urine[!] or if you insist, yeast nutrient from a home brewing supplier. Add a brewing yeast, shake up and keep at 77ºF | 25ºC. Over next 2 weeks or so it will brew up about 0.5 ounce | 15 grams CO² for every ounce | 30 grams of sugar used. Keep a few going at once, starting a new one every 3 days or so. With added CO² growth is phenomenal! We measured 15 inch | 38 cm growth in 8 days under a 250watt HPS bulb [tubular clear, Horizontal mount]. A good container is a 1 gallon | 3.5 liter plastic milk jug, with a pin-hole in the cap. Also, the air-lock from a piece of clear tube running into a jar filled with water will keep microbes out and demonstrate the fermentation is working.
A variation is to spray seltzer water on the marijuana plants twice a day. This is not recommended by some authorities, and receives great raves by people who seem to feel it has enhanced their crop. It stands to reason this would work for only a small unvented closet, but may be right for some situations. It could get expensive with a lot of marijuana plants to spray. Use seltzer, not club soda, since it contains less sodium that could clog the marijuana plants stomata. Wash your marijuana plants with straight water after 2 or 3 seltzer sprays. It's a lot of work, and you can't automate it, but maybe that's good! Remember, being with the marijuana plants is a beautiful experience, and brings you closer to your spiritual self and the earth. Club soda will work if seltzer water is not available; but it has twice as much sodium in it. A very diluted solution of Miracle Gro or Formula Flora plant food can be sprayed on the cannabis plant at the same time. One factor of using seltzer water is it raises humidity levels. Make sure your venting humidity during the dark cycle, or you could risk fungus and increased internode length.
Don't spray too close to a hot bulb! Spray downward only, or turn off the lamp first.] Even though CO² enrichment can mean 30% to 100% yield increases, the hassle, expense, space, danger, and time involved can make constant or near constant venting a desirable alternative to enrichment. As long as the marijuana plant has the opportunity to take in new CO² at all times, from air that is over 200 parts per million [ppm] CO² , the marijuana plants will have the required nutrients for photosynthesis. Most closets will need new CO² coming in every 2 or 3 hours minimum. Most city's' will have high concentrations of CO² in the air, and some marijuana growers find CO² injection unnecessary in these circumstances. Some marijuana growers have reported that high CO² levels in the grow room near harvest time lower potency. It may be a good idea to turn off CO² 2 weeks before harvesting.
Foliar feeding to increase growth
Foliar feeding seems to be one of the easiest ways of increasing yield, growth speed, and quality in a well vented space, with or without elevated CO² levels. Just prepare a tea of worm castings, fish emulsion, bat guano, or most any other plant food right for the job and feed in vegetative and early flowering stages. It is not recommended for late flowering, or you will be eating the sprayed-on material later. Stop foliar feeding 2 to 3 weeks before harvesting. Wash off the leaves with straight water every week to prevent clogging the stomata of the leaves. Feed daily or every other day. Best times of day to Foliar feed are 7 to 10am and after 5 in the evening. This is because the stomata on the underside of the leaves are open then. Also, the best temperature is about 72ºF | 22ºC, and over 80 ºF | 27ºC, they may not be open at all. So find the cooler part of the day if it's hot, and the warmer part of the day if it's cold out. You may need to spray at 2am if that's the coolest time available. The sprayer used should atomize the solution to a very fine mist; find your best sprayer and use it for this. Make sure the pH is between 7 and 6.2 [6.5 is perfect]. Use baking soda to make the solution higher pH, and vinegar to make the solution lower pH. It's better to spray more often and use less, than to drench the marijuana plants infrequently. Use a wetting agent to prevent the water from beading up, and thereby burning the leaves as they act as small prisms. Make sure you don't spray a hot bulb; better yet, spray only when the bulb has cooled. Perhaps the best foliar feeding includes using seltzer water and plant food at the same time. This way, CO² and nutrients are feed directly to the leaves in the same spray. Foliar feeding is recognized in most of the literature as being a good way to get nutrients to the marijuana plant later when nutrient lockup problems could start to reduce intake from the roots.
It is important to wash leaves that are harvested before they are dried, if you intend to eat them, since they may have nitrate salts on them.]
Negative ion generators
Negative ion generators have been used for years now to cut down on odors in a grow room, but reports are coming in that a negative ion generator will increase growth speed and yield. No true evidence to support this, however it does make sense, due to the fact that people and animals seem to be altered in a positive way by negative ions in the air, so marijuana plants may "feel" better too. Try putting one in the marijuana grow room. You may notice the marijuana buds don't have as much scent when picked, but that may be desirable in some cases. Some generators have reversed cycles that collect the dust to a charged plate. It is also possible to use grounded aluminum foil on the wall and shelf where the ionizer sits, to collect these particles. Just wipe the foil clean once a month. It should be grounded to an electrical outlets ground wire. If you don't cover the wall and shelf with paper or foil, the wall will turn dark with dust taken from the air, and you will have to repaint that wall later.