When looking at the three most common forms of growing marijuana, you will find inside, outside and greenhouse growing. Which route you choose will likely boil down to what kind of weather your area has and what your local legislation says about growing marijuana. Most countries share the same thoughts on owning or growing marijuana, so we will focus on growing marijuana plants indoors to help you avoid legal consequences. The best marijuana plants come from the best marijuana seeds, so browse our seedshop if you do not already have the seeds you want to start your crop with. Look for a variety that you would enjoy watching grow until you can smoke it, paying close attention to the length of time it will take your plants to grow and flower.
You will want to prepare your home before starting to grow marijuana plants so that you do not have run-ins with your neighbors. You will want to make sure your growing location will not leak light or any smell to avoid any unnecessary attention. Ideally you want a lightproof growing location that can also be made smell-proof and waterproof. Carbon filters will help with the scent and fans will allow fresh air to flow around the plants. With the room needing to be lightproof and also not leak any light, a black plastic sheet that is thick enough to not show light either direction may be your best investment. Buying a high-quality sheeting is something that can be reused for many years, so the overall money can be quite minimal after time. With as much light as marijuana plants crave, you can increase the benefit of the sheeting if you line it with a white plastic, paint the growing location white or use aluminum foil on the walls to reflect the light back on your marijuana plants.
A single mother plant is used to clone new and smaller plants by using cuttings taken from that female plant directly. You will want to choose a mother plant that had good resilience, strength and a good yield so that your new marijuana plants will offer you the same potential outcome. Some marijuana growers find cloning difficult and they are unable to reproduce the same results, so they choose seeds. You will want to make sure the seedbank you choose has a solid reputation because not all seedbanks are created equal, nor are their products.
You will want to start at least two times as many seeds as there is room for the final plants because the plants will either become female or male plants, and you are striving for only the strongest of female plants. To germinate marijuana seeds, you can either place seeds between wet sheets of paper towels or you can put the seeds directly into your growing medium. Both methods will require a few days for germination to start, but keeping the seeds moist and covered with plastic wrap will help the process happen quicker. Once you see the beginning of the seed popping out, placing the new seedlings under a light will help them take off. The plants should stay 4-8" (10-20 cm) away from the light, adjusting as the marijuana plants begin to grow. This process should involve 18-24 hours of light per day and will usually take up to two weeks to produce seedlings, depending on which variety you have chosen to grow. When your marijuana plants hit the 3-4" (7.5-10 cm) mark, allow the soil to dry up some before giving the plants more water. This will encourage root growth. New growers often over-water their marijuana plants, so make sure only to water when needed.
Similar to house plants, flowering and growth depend on just how much light (or lack thereof) each plant gets. In the case of marijuana plants, the lighting will tell the genetics of the plant that spring has sprung and that makes it grow-time. Just like in nature, later on during the growing season the light will decrease, telling the internal genetics of the plant to flower by the release of the hormone phtyochrome. This allows the plant to focus entirely on flowering. Mimicking this pattern is the point of regulating lights in a growing location.
If you want a great yield, then you need to supply great light. A single fluorescent bulb will work for growing some seedlings, but for flowering you will need one 400 watt bulb for each four plants you are trying to get to flower. The stronger light you have, the better yield you will get, so many professional growers will use 600 watt sodium bulbs instead.
A room that is white from top to bottom will help reflect the most light back to your marijuana plants. Ensuring that your outlets are able to handle the necessary draw that a growing location would create is another fundamental step to preparing your grow room. A good way to test this is if you can use a light, the vacuum and your washing machine without having a fuse blow.
If you are using the 600 watt bulb, it will likely draw about 6 amps with a 110 volt service, so you want to be sure this will not cause trouble in your house. If you use this bulb and it starts a fire within your wires, your insurance company will end up not writing a check to you to cover the repairs after this illegal activity. We tend to avoid incandescent bulbs because of their inefficiency, and go with fluorescent bulbs because of their availability and price. You should put at least 25 watts in each square foot (30 sq. cm) of growing space, with as many different shades of white tubes as you can find to help mimic sunlight. Metal Halide (MH) bulbs have grown in popularity recently with growers because of their brilliant white light which most marijuana plants thrive off of. You will have greener plants that are stronger than ones grown under a fluorescent lighting system. Using sodium lamps will give off an orange or bright yellow light, similar to a streetlight, which many growers use for the flowering process.
If you don't mind dirty work, we recommend soil because of the increased flavor that your harvest will have. Hydroponics is much cleaner, but your entire crop can be ruined by a simple mistake or two. You will find that taste often leaves something to be desired when using hydroponics, but experienced growers can achieve good flavor with this method. You also need to keep in mind that you cannot move a hydroponics system where you can move pots if it becomes necessary. Many marijuana plant growers have gotten caught due to the oversight of their hydroponic system starting to leak, causing attention to be drawn to their activities.
Marijuana plants require 14 main chemicals for healthy growth. Three of them are considered macro-nutrients: phosphorous (P), potassium (K) and nitrogen (N). Marijuana plants require vast amounts of these nutrients and are listed on most fertilizer packages as NPK. Secondary nutrients, such as sulfur (S), magnesium (Mg) and calcium (Ca), need to come in as the second most abundant, and the micro-nutrients need to come in third.
These nutrients are zinc (Zn), manganese (Mn), iron (Fe), cobalt (Co), molybdenum (Mo), chlorine (Cl), boron (B) and copper (Cu). You will likely only see the macro-nutrients listed on packages because of the minute quantities required of the other nutrients. When focusing on growth, you will want a nitrogen-heavy fertilizer, like a 20/10/10 mixture, and when focusing on flowering, you will want a phosphorous-heavy fertilizer, like a 5/20/10 mixture. You want to make sure not to over-fertilize your marijuana plants because this can ruin an entire crop. Curling leaves is a common sign that too much fertilizer is being used. All natural products are required for marijuana plant growing because smoking your harvest is your ultimate goal. Avoid fertilizers that are supposed to be for marijuana plants as they are typically little more than a tomato fertilizer that someone put a new label on and then increased the price tag. Manure is the best organic fertilizer you will likely be able to find. Avoid using fish emulsion, however, unless you have a powerful air filtration system due to the smell.
Keep in mind how much oxygen the roots of marijuana plants need when you are combining your growing medium. You will want to make sure that there is some perlite or sand in your mixture, giving the necessary oxygen and holding on to more water so the plants do not dehydrate. You will also want to make sure your pots are large enough for large plants, which will have large root balls. The pots will need small holes near the bottom of them so that excess water will be able to drain out because excess water will harm the roots, potentially killing your plants. Using clay pots should be avoided as well because of their tendency of hyper-evaporation.
It does not really matter which kind of pH meter you use, because they all do the same basic actions. You will just want to make sure you get the most accurate meter you can find. There are paper strips that are used once, or electronic meters that can be used repeatedly. Each shows you where your soil and water come on the scale of acidic (zero) to basic (fourteen), with balanced being a pH of seven. The electronic meter is a good investment if you plan to grow marijuana plants long-term to save money over having to replace the strips. The probe simply goes into your soil and you get a reading, instead of having to wait for the strips, saving you time. If your solution is too basic, or alkaline, you can bring the scale back down by using nitric acid, vitamin C, vinegar or sulfuric acid. If your solution is too acidic, lime, wood ashes or bicarbonate of soda will bring the levels back to balanced. Use a few drops at a time to adjust the pH and measure after some time is given for the solution to combine. The last thing you want it to cause chemical burns to yourself or your marijuana plants.
Stability is the key to a strong marijuana crop. Even though the plant can withstand temperature extremes, it will slow down all growth or flowering. Keeping your crop around 68 °F (20 °C) is ideal because growth will stop below 57 °F (14 °C) and bugs and fungi will become a problem if the room is over 75 °F (24 °C). Your grow room will be quite warm if you use the 600 watt (or higher) bulbs, especially during the hot summer months, so you may need a fan for the room. During cold winter months, you may need a heater when the lights get turned off at night to avoid your plants getting too cold. If you plan to use fans, make sure they only blow gently on your plants so that it does not stress the plant into creating a thick stem when you would rather it focus on better growth and flowering.
You will want to try and keep your grow room at about 50% humidity so that your marijuana plants are not going to the extreme. Keeping your humidity monitored is the best way to avoid a humidity that is too high, creating a breeding ground for many pests and plant diseases.
Once your plants reach a few inches (cm) high, and your plants have three sets of leaves growing, you should cut the top two leaves allowing the marijuana plant to split into two branches. This will create a bushier plant, especially if repeated with a recovery period in between each cutting. If done properly, this can help boost your yield exponentially. However, if not done properly, this can harm the plant, slowing down the growth to focus on plant repair.
Once your marijuana plants reach the height you desire, you can flip the light cycle to 12 hours of bright light and 12 hours of pure darkness. This will start the flowering process within your marijuana plants, getting you one step closer to harvest. Once the little hairs on your marijuana buds have turned about 75% brown (or red or orange, depending on variety), it is then time to harvest your crop.
Removing the leaves with your marijuana plant still sitting in the pot tends to make the process a bit easier. Make sure to remove any pointed leaves that are sticking out of your marijuana buds as those tend to make the flavor harsh and sharp, hurting your throat when you smoke. After the bad parts of the plant are removed and only smoke-able material remains, hang your marijuana plants upside down with good protection and ventilation so that no rodents or other pests can harm your crop. Rodents love munching on marijuana plants and seeds, so keep a close eye on your crop. Follow the lead of your marijuana plants during the curing process, giving as much time as is necessary for proper curing, so that you do not end up with a sharp-flavored crop, but instead you have the heavenly smoke that you desire. Heaters should be avoided during this process so that you do not ruin the flavor of your crop.
Want to read more about marijuana? Go to our marijuana grow guide.