Green plants obtain all their energy by photosynthesis This process converts light energy into chemical energy. The “photo” part of the term comes from light. The change from light energy to chemical energy accounts for the “synthesis” part.

Some people refer to the conversion as carbon fixation. The plants takes CO2 and water and converts them into oxygen and carbohydrates. There is an opposite process that also happens with plants, called respiration. respiration occurs in the dark and the light. It shows up as water that is “breathed” out of the foliage.

Evolution has decreed that plants vary in how they carry out the two processes. Not all plants need the same kind of light or the same quantity. Wide spread plant diversity is the result of this fact. This is a process that occurs at the molecular level. It also determines how plants react to radical changes in photo-period. More important, how they make use of CO2 is also controlled by this.

Carbon fixation is the reduction of carbon dioxide into an organic compound. How they fix carbon divides plants into 3 main categories. They are: CAM, C3 and C4 plants. Marijuana and many vegetables are examples of C3 plants. Gardeners care about this because the different plants use CO2 in different ways. C3 plants do not store CO2 for later use. They use CO2 as long as they are exposed to light, but they use it in real time.

Additionally, C3 plants like cannabis have the ability to use higher concentrations of CO2 than that found in our current environment. Assuming there is enough light and the plant is vigorous they can use up to 2000 ppm of CO2 vs 400 ppm. The result id more growth and more crop. Darkness is not required for C3 plants – they can grow 24 hours a day.

24 hours per day versus 18 means the same amount of photosynthesis in 25% less time. Switching the plants from 24 hours a day to a 12/12 cycle can be extreme, though. If you’re too abrupt you may get a hermaphrodite, or some other negative outcome. This will erase the advantages gained from using more carbon dioxide.

So, bottom line, if you’re giving your plants CO2 then do it while the lights are on. If you have a dark period each day, give them the CO2 when the light cycle starts.

1. Be careful to not over water your plants when growing marijuana. When the top part of the soil has dried out water them, and not before. Weed doesn’t like to be too wet, and doesn’t like wet feet. If they’re wilting and the soil is dry,water them, but, if the soil is wet, don’t water them again.

Over watered marijuana plants

Over watered marijuana plants

2. Don’t use too much fertilizer. You can toxify the soil and burn the plants.

3. Don’t start with unknown seeds- this isn’t the worst thing in the world to do, but beware. Plant genetics play a huge role in your success. If you don’t know what seeds you have you won’t know what kind of plant to expect. It can be long tall and spindly, it could be an auto-flowering plant, or it could be an indica, a sativa or a super smelly skunk that gives your operation away. If the risk doesn’t matter then go ahead and have fun – otherwise purchase known quality seeds.

4. Be careful in germination. Once the seeds are in the dirt leave them alone. The germinated seeds are tough but you can damage the tap root or introduce pathogens that can kill them. Try tweezers.

5. Keep the project secret. Flies can’t get into a closed mouth. If too many people know you’ll get caught or your garden will be ripped off. Law enforcement or crop thieves are a real threat.

6. Don’t introduce someone else’s clones or plants to your garden. A pest free grow show is a hassle free grow show. If you get pests they can be tough to eradicate completely. One of the most common sources of pests are other plants. Practice safe sex with your plants when you’re growing marijuana.

7. Don’t over cultivate. New growers spend too much time worrying about unimportant things. A yellow leaf here or there is not the end of the world. Let Mother Nature do her thing. Don’t check your plants every few minutes just to make sure everything is ok.

You don’t need to spend a bunch of money on gadgets and hormones. Light and nutrients are all you really need. You can experiment with stuff later, once you’ve seen the process through once and know what’s what. On my second crop I used a hormone spray and over-did it with really strange results. It worked, but the buds weren’t recognizable to most people.

9. Read directions before use. Whenever you’re using fertilizer or pesticides, read the directions carefully. It’s the same with PH. Don’t cut corners or hurry.

10. Probably the biggest tip is to create a good environment for plant growth. Weed wants to grow, and it isn’t hard to help it. The PH should be between 6.5 and 7 and the temperature should be warm – about 24 degrees celsius and the soil should be well drained – create these conditions and you should do fine. New plants and clones also need humidity, so use covers.

So long as you follow these simple ten steps you should get a great crop. I was blown away by my first success. Don’t try to grow the biggest and best your first time out. Just learn the ropes and get a harvest. You can refine your cultivation procedure as time goes by.