How to Grow Marijuana Indoors

If you want to know how to grow marijuana indoors on your own, there are several steps to follow. Be forewarned, growing marijuana indoors is not as easy as throwing a few seeds in your garden and watching the vegetables grow. Marijuana requires knowledge, practice, and a bit of patience.

But, if you are ready to give it a shot, we will walk you through the basics. Follow the steps and you too can have a home-grown supply of marijuana.

Choosing the Strain and Buying the Seeds

Some folks already have a specific strain in mind and others simply want to grow whatever is available. If you have specific requirements you will need to look online for a seed bank that offers your preference. Shopping for seeds when your requirements are not so specific will be easier. Either way, your first step is to choose the strain and find a source for seeds.

Cannabis seeds come in three general varieties:

  • Regular seeds
  • Feminized seeds
  • Autoflower seeds

Regular Marijuana Seeds

Regular refers to seeds that were harvested from cannabis plants. They are probably not inbred or crossbred with other seeds. However, you are getting a mix of male and female seeds and only female seeds produce buds. Plant enough seeds so that you are sure to be planting ones that will produce buds (flowers) instead of pollinate the others. The good part is that these seeds have a purer chemical profile as they have not been crossbred.

Feminized Marijuana Seeds

The advantage of buying feminized seeds is that all of the plants that grow will produce buds. On average you will get twice as much product for the same number of plants that you are tending. Many growers go this route to save time and money. When you go with a reliable seed bank with a good reputation, you can be assured that you will get plants that flower like they are supposed to.

Auto-flowering Marijuana Seeds

This is the “easy to grow route.” These seeds germinate promptly and need less light than the other seed types. These qualities make auto-flowering marijuana seeds a good choice for novice growers. You can learn the ropes of marijuana growing and get a crop with less effort and less attention to complicated growing methods. However, this choice can be a bit dicey in terms of the final product as some seeds will produce impressive yields and others may not even bloom!

Payment for Cannabis Seeds

Ecommerce 2140603 1920 1024x438 1

Do not send cash when buying cannabis seeds. Reputable online seed banks take debit and credit card payments and even cryptocurrencies. Always go with a secure payment option!

Check out our list of the best seed banks before you go shopping.

When you order seeds online there is always a chance that customs will confiscate your seeds or that they will simply get lost in transit. The most trusted seed banks will generally replace any lost seeds.

Setting Up the Growing Area

After you order seeds it can take as long as 30 days to get them. During this time is when you need to be setting up your indoor garden for growing cannabis plants. The first thing is to determine how much space you can devote to your effort. This will help you decide on using grow boxes or grow tents. The space you choose only requires room to put the plants and an electrical supply for your lights. It does not need to look like a professional greenhouse so you can use your spare room, a closet, or just a roomy cabinet. Figure out how much space you can devote to the project and then start thinking about the equipment to purchase and how many seeds you can plant at any one time.

There are growers who get by with an investment of a hundred dollars and those who invest thousands of dollars. Start by determining your available space.

Because you are doing this for the first time, leave a margin for error. If you start small and start with a simple operation you can add on as you gain experience and not waste money and time on features that you end up not liking.

In fact, to get good results you don’t need a super-sophisticated setup. The basics include grow lights, hydroponics or soil, and good ventilation to get good results.

Premium Autoflower

Growing Mediums for Cannabis

Both hydroponics and soil have their advocates for growing cannabis. Debates on the virtues and drawbacks of one versus the other can be quite heated. Both approaches can give you a nice crop of healthy buds but both require attention to detail. There are disadvantages and advantages to each way of growing.

When you read about soil versus hydroponics, you may be reading about growing out of doors or indoors. Most commonly outdoor growers use organic soils and hydroponics is used for the majority of indoor growing. However, if you vary from these approaches you are not condemning your efforts to failure. You simply need to learn what to do for your growing method.

There are indoor growers who use high-quality potting soil and get excellent yields. When you go this route make sure you are using good potting soil. And, when outdoor growers go with hydroponics, they are making sure that lack of rain will not doom their crop. In this case, knowing likely weather conditions is important.

If you do both methods the right way, soil tends to give you higher yields. To take advantage of this fact with indoor growing, make certain that you have a growing space with enough light and high ceilings.

A strong argument for hydroponics is that you can manage your plants more precisely in terms of water and nutrients. Growing in soil is not as exact. Check out the best hydroponic growing systems before buying anything.

How much space you have may dictate the method you use as a small space works best with soil and manual watering while hydroponics requires more room (and a water supply).

Plants grown in soil tend to be stronger but indoor growing with hydroponics typically gives you higher cannabinoid levels.

Choosing Grow Lights

All plants need light similar to sunlight. Growing marijuana under old incandescent lights does not work. The three common lights to use are fluorescent, HID, and LED. Choosing the best lighting is important for getting the best results.

LED Lights for Growing Cannabis

LED lights have been in use for a long time and they are known to be quite efficient and easy to set up. But, when you are providing lighting for lots of plants, LED lights can get pricey. This kind of lighting generates less heat than other light sources and last a long time. You will also find them in a variety of designs that can fit many different growing spaces. These are available both in stores and online.

HID Lights for Growing Cannabis

High density discharge lights have the advantages of generating more light for the same cost of electricity used than other methods. They usually cost more than fluorescent lights but you save on your electric bill. They are, however, less efficient than LED lights.

Fluorescent Lights for Growing Cannabis

Small growers tend to use fluorescent lighting because it does not generate much heat and thus does not need a cooling system. They are inexpensive to buy but use electricity less efficiently than LED and HID.

Other options include incandescent and HPS lighting. We suggest that beginners avoid both of these approaches.

Timers and Your Available Time

If you will not be around all of the time to monitor your indoor plants and turn the lights on and off, purchase a timer. This will help you avoid leaving the lights on all night or leaving your plants in the dark all day if you are not home!

Ventilation Systems for Growing Cannabis

Growing cannabis in a closed space means that you need to control humidity, temperature, and levels of carbon dioxide. Do this by setting up a ventilation system, dehumidifier, and CO2 regulator. For a small setup, you may be able to get by with a fan.

If you are using just a fan, it needs to be able to move the entire volume of air in the growing space every ten minutes. And exhaust fan that moves 20 cubic feet of air a minute will be sufficient for a 200 cubic foot space. You need to multiply this capacity by the volume of your growing space. If you are concerned about C02 buildup, you can monitor levels and use a carbon filter.

However, for beginners working with a small growing space and a few plants, a simple fan setup is usually sufficient. Just make sure to place the fan so that its air flow moves air around the entire growing space.

For folks who are growing cannabis in the winter in northern climates, you need to make certain that the space does not get cold. If your lighting does not do the job, you need to add a heater.

Growing Marijuana

You have set up the growing space and received your seeds. What comes next?

Esteban Lopez T9jQie6cUhg Unsplash 1024x683 1


The first step is getting your seeds to sprout. Do this by simulating outdoor conditions even if you are doing this in a grow room. Put seeds in your growing medium and you will start to see seedlings sprouting in up to a week. Many times you will use a different medium for sprouting the seeds than for later growth. If this is the case, carefully transfer the seedlings to the final growing medium.

The Stage of Vegetative Growth

In order to produce buds and a harvest, you first need to have a mature plant. This starts to happen when you begin to see large, green leaves. The roots of your plants are growing and the plants are getting taller. This is the vegetative growth phase. This will go on for 3 to 5 weeks depending on how much light your plants are getting.

Clipping and Cloning Marijuana Plants

Some growers multiply the number of cannabis plants they are growing by using a technique called cloning. This is a really a simple process in which you clip of sprigs of the growing plant and replant them in your growing medium. This gives you more plant faster than if you only use seeds.

You will want to use a gardening scissors of good quality and sterilize the cutting blades. Pick a strong stem or branch and remove excess leaves and smaller branches leaving just a cluster of leaves at the top. Plant this stem and keep the light low until you start to see root development. You can do this in soil or hydroponic solution. Either way, it takes roughly a week for the new plant to take.

Marijuana Flowering

You will know that the vegetative stage is over when the plant has gotten large and when it starts to bloom. At that point, you can even harvest your own cannabis seeds for future use!

When the plant flowers, you want to give it more light. Some grow lights have a “flowering mode” that you can switch to at this point. Because plant development at this point does better with red spectrum light, it is good to have a setup where you can switch that on when needed. Or you can add more lighting. Here is where adding incandescent lights is useful as they are rich in the red end of the light spectrum.

Set your light timer to a twelve and twelve hour cycle and make sure that during “nighttime” the growing space is dark. This may mean sealing or covering places where light can “leak” in.

Make certain that the light you are providing is reaching all plants equally. This is the most critical phase of growing marijuana indoors and where things too often go wrong.

Water Issues

Cannabis plants that don’t get enough water have spotted, discolored, or dry leaves that fall off. If you overwater them and overheat them because you are not providing sufficient ventilation they will get mold and even smell bad.

You can stay ahead of these problems by routinely observing your plants and adjusting fans and lighting as needed.

Note: Toward the end of the flowering part of the growing cycle you may see some yellowing of some leaves. This is normal.

The entire growth phase from spouting to harvest will last about two months. But, this time will vary with the growing conditions you provide your plants.

Nutrients of Healthy Cannabis Plants

It does not matter if you are using hydroponics or growing in soil, your marijuana plants do best with proper nutrition. There are many fertilizers and nutrient solutions that give you great yields, pretty flowers, and more potent THC content. For beginners, we suggest that you choose a product with instructions that are easy to follow.

Parting Thoughts

If you like the idea of growing your own cannabis, think about doing this for a long, long time. When you start out there will be a lot of trial and error. Use your mistakes as lessons and keep moving forward. The biggest issue for many growers is the commitment of time required for excellent yields. Whether you grow sativa or indica, the plants need careful attention for good results. Time invested early on in learning what to do and how to do it will pay dividends later on. As you go, remember that this is supposed to be enjoyable. Enjoy the stages of growth, the lessons learned along the way, and, of course, the final product!

Leave a Comment