Marijuana grow space
Choosing a space to grow your marijuana indoors is just as important as choosing the proper space to grow your marijuana outdoors. Your garden should be located in an out of the way place [not the bedroom]. Basements, attics and closets are all great places. Once you have a few possibilities in mind make sure the have access to electrical outlets. Plan ahead for anything that might require a repairman to visit your house. If your garden is located in the same room as the furnace and the furnace explodes, your in big trouble. Once the permanent garden location has been selected it is time to prepare it. [For the rest of this guide we will assume you have chosen a closet as the marijuana grow space]. Paint the walls flat white. Do not use tin foil because it can actually focus light like little laser beams and burn holes through the leaves. Next, cover the floor of the closet with plastic. This will help stop water damage to the floor.
Containers | Pots
Your marijuana plants will need to be grown in some kind of pot or container. Large plastic pots [like the ones bushes come in] work best. Fill the bottom inch | 2.5 cm with large gravel to help drainage. And the rest with high quality potting soil with some sand mixed in. Buckets can also be used but drill drainage holes in the bottom. If your containers previously held other plants then they must be sterilized with bleach or alcohol. [Make sure you rinse them well]
Lighting
Since there is no sun in your closet you will have to provide a sun loving plant like marijuana with a lot of artificial light. There are three options available to the grower: fluorescent lights are cheap, efficient and don't put out much heat. Metal halide or MH bulbs, are more expensive but put out much more light than fluorescent. They also put out more heat so ventilation is needed. MH bulbs also require a separate ballast in order to work. High Pressure Sodium lamps or HPS, put out as much light as MH lamps but with a little less heat. Ventilation and a separate ballast are also required.
Fluorescent light
Fluorescent lights are the cheapest light to use. They produce little heat so ventilation may not be needed unless the space is very small. The light spectrum put out by these lights is suitable for all stages of cannabis growing. Because fluorescent disperse light over a large area, they need to be kept within 3 inches | 7.5 cm of the tops for the marijuana plants to receive enough light. This means you will have to mount the lights in a way that the can be raised everyday.
Metal halide light [MH]
Metal halide lamps put out the most light. They also produce allot of heat. A strong fan is needed to keep room temperatures down. MH lamps put out light mostly in the blue spectrum. Blue light is used best by the plant during vegative growth. MH lights can also be used for flowering with no adverse effects. A separate ballast is required for these lights to work. They come in sizes from 40watts to 1000 watts. One 1000 watt lamp will provide enough light in a closet to grow four marijuana plants.
High pressure sodium light [HPS]
High pressure sodium lamps put out almost as much light as MH and with less heat. Good ventilation is still required though. HPS lamps produce light in mostly the red and orange end of the spectrum. The marijuana plants use this light best when flowering. HPS lamps can also be used for vegative growth with little slow down in foliage production. HPS lamps require a separate ballast for operation. Some marijuana growers switch between MH and HPS depending on what stage the marijuana plants are in. MH is used in vegative growth and then the light is switched over to HPS once flowering begins. Most growers use fluorescent to start seedlings and root clones. The fluorescent are weaker than the MH and HPS lamps and therefore do not stress them too much. Choose whatever light is best suited for your situation. If your are growing in your attic go with MH or HPS.
Factors affecting the rate of photosynthesis
There are other factors other than the obvious amount of light that reaches the marijuana plants that affect the rate of photosynthesis. These can be manipulated by the grower to achieve maximum speed of growth and larger yields in a shorter period of time.
Humidity
The humidity in the environment is the amount of water vapor present in the air. Most marijuana growers know that humidity in excess of 85% increases the probability of the appearance of bud mold. The humidity is also critical during germination when the seedlings are extremely fragile. Humidity should be kept over 80% at this stage in the plants life to prevent the soil from drying too fast. Experimentation has shown that a relative humidity of 65% to 80% increases growth rate. Below this level the marijuana plants develop extremely narrow and tissue paper thin leaves to try to prevent excess loss of water. Above 80% relative humidity the plant have trouble disposing of toxic chemicals through evaporation.
Temperatures
Marijuana can survive temperatures from 32 °F | 0 °C to over 100 °F | 38 °C . Marijuana will grow best with a temperature of 70 to 75 °F | 21 to 23 °C day and night. Higher than 90 °F | 32 °C the enzymes within the marijuana plant begin to breakdown and photosynthesis is affected. The same is true for low temperatures.
Carbon Dioxide [CO² ]
Carbon dioxide is a gas that is essential for the light reactions in all plants that carry on photosynthesis. CO² is absorbed through the leafs stomates and is combined with water and light energy to form glucose [used by the plant as energy] and oxygen [which is released]. Therefore supplementing CO² to the existing amount in the air will speed up photosynthesis and therefore, growth will occur faster. Experimentation has also shown that CO² can help marijuana tolerate higher temperatures [up to 95 ºF | 35 ºC ] with little affect on the rate of photosynthesis.
Water
Although only a small portion of water absorbed by the marijuana plant is used in photosynthesis a shortage of water does affect the rate photosynthesis occurs. This happens because when the marijuana plant is low on water the stomates on the leaves close preventing the release of waste gases and other toxic chemicals. This closure will severely slow down or even stop photosynthesis from occurring.
Sea of Green [SOG]
Sea of green, or SOG, is the theory of harvesting many small plants frequently, instead of large plants less frequently. In an SOG setup the closet is divided into two light tight spaces. In the top space the lights are permanently set on a 12hours | 12hours light | dark timer. On the bottom the lights are kept on for 18 hours per day. Fluorescent lights are used throughout. The bottom shelf is used to start seedlings and root clones. The top shelf is used for flowering. Using this setup harvesting can take place once a month.
Ventilation
Marijuana like all other plants puts out waste through the stomata on it's leaves. Outdoors wind, rain and sun are present to evaporate these toxins from the leaf surface. Indoors the cannabis grower must create an environment. The best way to do this is with a fan of some kind. If the marijuana grow room is large enough then an regular cooling fan can be placed inside and left on all the time. If you are running a small closet operation then just opening the door twice a day to look at them will create enough air movement for healthy growth. A fan controlled by a thermostat will also work well. These can be found at most electronics stores. If a large number of marijuana plants are to be kept a dehumidifier may be needed. If humidity levels are too high then the chances of mold will dramatically increase.
CO² supplementation
Some marijuana growers add CO² to their grow rooms to increase growth rate. This has proved itself to be effective in many experiments. CO² supplementation also helps the plants withstand higher temperatures of up to 95 ºF | 35 ºC without slowing down growth. There have been complaints however, that CO² supplementation during flowering reduces potency. Therefore, CO² should be stopped when the lights are turned to 12hours | 12hours.
Early sexing
Since you control the light cycle in an indoor marijuana operation it is easy to sex the marijuana plants early and eliminate all the marijuana males. Just turn the lights down to 12hours light | 12hours dark when the marijuana plants are 8 inches | 20 cm high. Use a magnifying glass to examine the flowers and eliminate all the male marijuana plants.
Obtaining marijuana seed
If you do want to pollinate some females to produce marijuana seed for the next crop it can be done so that only a few marijuana buds are pollinated and the rest remain as sensemilla. First collect pollen from a male marijuana plant. The male plant should show desirable characteristics, like fast growth, potency and resistance to pest and mold. To collect the pollen just shake the branches into a plastic bag. Black paper can also be used to collect pollen. Just spread it on the floor around the marijuana plant, in a few days the paper will have quite a bit of pollen on it. The pollen can be stored in film canisters until it is needed. When needed, use a paintbrush to brush on the pollen to the lower branches of the female cannabis plant.The best way to be sure that all the marijuana seeds are mature before harvest is to just never harvest the pollinated branches. Let them die naturally so you can be sure they produce viable marijuana seed.
More information about male and female marijuana »
Harvesting and drying marijuana
When you want you marijuana plants to start flowering just turn the lights down to 12hours light and 12hours dark. Then be patient and wait for flowering to complete. It helps the drying process a little if you don't water the week before harvesting. When you cut the marijuana plants remove the large fan leaves and add them to your compost pile as they are not usable for smoking. Place the marijuana plants in shoe boxes or paper bags and stir them around daily. In about three weeks the buds should be totally dry and ready to smoke.
