A beginner’s guide to growing marijuana indoors

If you’ve decided to start growing your own cannabis, growing indoors is a great place to start. While outdoor growing has various benefits, indoor growing allows for more control, making it perfect for beginners.

To grow cannabis indoors, you’ll need a dedicated grow room, certain equipment, and cannabis seeds or plant cuttings called clones.

This beginner’s guide will help you understand how to set up your grow room and grow healthy cannabis plants indoors.

The benefits of growing weed indoors

Growing cannabis indoors has a number of benefits compared to growing it outdoors or in a greenhouse. These include:

• More control over your growing environment: Growing indoors gives you the ability to control how much light, water, and nutrients your plants receive. You can also control the temperature and humidity levels.
• Lower risk of infestation and disease: With indoor growing, there’s a lower chance that your plants will develop diseases or insect infestations.
• Longer growing seasons: With an indoor grow room, you aren’t tied to the seasons or the weather. This means that you can grow cannabis throughout the year, leading to more harvests.
• More privacy: Even if you’re legally allowed to grow weed, growing indoors keeps your cannabis plants out of public view.

Are there downsides to growing cannabis indoors?

Growing indoors can be more costly than growing outdoors because of equipment expenses, including the purchase of grow lights, fans, and a hygrometer.

However, over time, growing cannabis indoors can end up being less expensive than buying cannabis flower repeatedly from a dispensary.

Setting up your weed grow room

You will need a suitable space for your grow room. This could be:

• A spare room in your home
• A garage
• A basement
• A large closet

For those with limited space, a cupboard can work as long as it’s sealed appropriately so that light cannot get in.

Cannabis needs time in the dark during its growth cycle, so you’ll have to be aware of this if you’re using an entire room to grow. If light gets into your grow area during the dark stage of the plant’s light cycle, it can stress the cannabis plants and lead to problems with growth.

If you have a small grow space, a grow tent may help your plants get the dark time they need by blocking any outside light.

Most new growers begin with a small grow room measuring around 3 feet by 3 feet, which can typically hold between four and nine plants. Only one light is needed to cover a space of this size. It’s often best to start small to understand the cannabis plant’s growth patterns before moving on to bigger projects.

Some states require that cannabis plants be grown out of the public’s sight. Keep that in mind when choosing where to set up your grow room.

What you’ll need

You’ll need the following items to grow weed indoors:

• Grow tent (optional): This is a special tent that’s black on the outside to prevent light from getting in. It also has a refractive material on the inside to cast light in different directions, which helps you get the most out of your grow lights. Use a grow tent if your grow room doesn’t get completely dark.
• Grow lights: You’ll need lights of the correct wattage (power level) to help your plants grow. You’ll also need some accessories to support your grow lights.
• Platform: The right platform has enough space for your plant pots.
• Plant pots: You’ll require pots of various sizes to store your plants.
• Intake fan: This is a fan that pumps new air into your grow room.
• Extractor fan: This is a fan that helps remove excess hot air from your grow room.
• Carbon filters: These filters attach to your extractor fan to reduce the smell of cannabis.
• Thermometer: This ensures that you’re keeping your plants at a temperature of around 79°F to 83°F (26°C to 28°C).
• Hygrometer: This device measures humidity to estimate the moisture level of your grow space.
• Timer: A timer switches your grow lights on and off automatically, which can be especially helpful when you’re not at home. Timers can also be useful for feeding in a hydroponic system, which is a growing technique that uses water instead of soil.

Choosing the best grow lights for weed

Grow lights are artificial lights that provide plants with the light they need to create energy and grow.

Each stage of plant growth requires different types of grow lights:

• For the vegetative stage, when the plant sprout begins to grow leaves, stems, and roots, you will want a grow light of around 100 to 125 watts.
• After around 4 to 6 weeks of vegetation, you should switch to a grow light of about 250 to 400 watts to trigger flowering.

Other lighting equipment you’ll need includes:

• A ballast: This controls the supply of energy needed to power the light.
• A reflector: Reflectors surround the top of the light to direct the light downwards towards your plants.
• Hanging materials: You’ll need a heavy chain or another material strong enough to hang your lights.

You’ll also want to consider the type of light:

• Halide lights: During the vegetative stage, most people choose metal halide lights as they produce more blue light, which is essential to a plant’s growth.
• Sodium lights: During the flowering stage, many people prefer sodium lights. These produce more red light, which supports healthy flowering.
• Fluorescent lights: These provide both red and blue light, which can be beneficial to seedlings.
• LED lights: LED grow lights are popular because they’re energy-efficient, don’t need to warm up, and can be used throughout the growing process. They’re more expensive than some other types of lights, but can be replaced less frequently.

Providing air circulation

Plants need fresh air and carbon dioxide to grow, so it’s important to keep air moving through your grow space. This is where extractor and intake fans come into play.

The main purpose of an extractor fan is to remove warm air from the room. Because warm air rises, your extractor fan must be placed high up.

Your intake fan is responsible for bringing fresh air into the area. It should be placed on the opposite side of the room from your extractor fan. Ultimately, the size and number of fans needed will depend on the size of your grow space.

In addition to fans, you may also need a dehumidifier or air conditioner unit to help control the humidity or the temperature in the room.

Choosing an indoor grow medium for weed

One of the advantages of growing cannabis indoors is that you have control over your growing medium.

For beginners, it’s generally recommended to start with soil, as it already contains most of the nutrients the plant needs. You can also use a mix of soil and coco coir, a growing medium made from coconut husks, which is known for retaining and draining water well.

With soil as your grow medium, you’ll need to fertilize your plants on occasion to ensure they maintain the proper balance of nutrients.

How to grow cannabis indoors

Growing cannabis indoors from seed to harvest involves several key steps, including choosing the right seeds, understanding your plants’ lighting and temperature needs, and checking in regularly to ensure your equipment is working properly.

1. Choose your cannabis seeds

The first step to growing weed indoors is buying high-quality cannabis seeds from a reputable source. Healthy seeds should be dry, hard, and dark in color.

There are a few different types of seeds you can choose from:

• Feminized seeds: Only female cannabis plants produce flower buds, so male plants are often discarded unless they’re going to be used for breeding. Feminized seeds only produce female plants, which can save you time, growing space, and money.
• Non-feminized seeds: Non-feminized seeds yield both male and female plants. These are ideal for people who breed cannabis to create new strains. They’re also less expensive than feminized seeds.
• Autoflowering seeds: Autoflowering seeds produce smaller-than-average cannabis plants that flower based on their age rather than a specific light cycle. This makes them beginner-friendly. They can also grow in colder climates compared to other types of seeds.

You can grow any strain of cannabis indoors. That said, some strains are generally known to grow better indoors than outdoors, including:

• Blueberry
• Blue Dream
• Master Kush
• Northern Lights
• OG Kush
• Skunk #1
• Sour Diesel

Many indoor cannabis growers prefer hybrid strains because they can be more resistant to insects, mold, and mildew. They can also handle a wider variety of climate conditions, like different temperatures and humidity levels, compared to non-hybrid (landrace) strains.

2. Germinate your seeds

Germination is a process that transitions your seeds from dormant to active so that they can sprout new growth.

To germinate your cannabis seeds, soak them in water and place them on paper plates or between paper towels. Within a few days, each seed should develop a small root. After their roots develop, they’re referred to as seedlings.

Once your seeds have become seedlings, transfer them carefully into small fabric pots filled with your chosen growing medium, taking care not to damage their fragile roots. Fabric pots offer more airflow than other materials, which is needed to help the roots grow.

Plant the seedlings about 10 millimeters deep into the medium. This is approximately the width of a standard paper clip. Keep the soil damp but not wet, as this can drown the seedlings. Using a spray bottle of water can help prevent overwatering.

If you want to skip the germination process, you can purchase cannabis plant cuttings, known as clones, at some dispensaries. By doing this, you can also skip the vegetative stage. However, clones are available in a more limited strain selection and are more expensive.

3. Move into the vegetative stage

Next, you’ll need to help your seedlings transition into the vegetative stage. You should provide them with around 18 to 24 hours of light per day and a temperature between 70ºF and 85°F.

At this stage, your plants must be watered regularly. They’ll also need extra nutrients, especially nitrogen. If you didn’t get feminized seeds, this is the time to identify and remove all male plants.

4. Monitor the flowering stage

In the flowering stage, female plants put their energy into producing thick, heavily scented flower buds. At this point, you should transition your plants to a light cycle of 12 hours of dark and 12 hours of light per day.

Once the flower buds are almost completely developed, you can stop giving the plants additional nutrients. However, they will still require regular watering.

Depending on the type of plant, flowering can take between 6 and 14 weeks to complete:

• Indicas and auto-flowering strains usually finish flowering after about 6 to 9 weeks.
• Hybrids usually finish flowering after about 8 to 12 weeks.
• Sativas usually finish flowering after about 10 to 14 weeks.

Check the specific flowering time of your cannabis strain for a more exact flowering time window.

Some people determine the end of the flowering stage by looking at the buds’ trichomes, which resemble tiny hairs. During flowering, these trichomes usually transition from clear to cloudy white, and then to an amber color.

Most growers harvest the buds when the trichomes are between white and amber. The levels of tetrahydrocannabinol (THC) are the highest when the trichomes are white, and become less and less strong once they turn amber.

5. Harvest and cure your buds

Now, you can harvest and cure your cannabis buds.

First, you’ll want to cut the main stem of each bud. Next, cure the buds you’ve collected by hanging them to dry in a dark, dry, and cool area of your home. Curing can take up to 5 weeks and helps preserve your buds and prevent them from growing mold.

Final tips

Growing cannabis indoors as a beginner can take some trial and error, such as finding the ideal lights and knowing when the best time to harvest your buds is.

That said, these tips can help you along the way:

• Learn from experts: Find expert tips from experienced growers in books or by searching online cannabis forums.
• Choose a beginner-friendly strain: Some strains are easier to grow than others. Stick to beginner-friendly strains, like Blue Dream, Northern Lights, or OG Kush.
• Keep it simple: Most people don’t need the most expensive equipment in order to successfully grow cannabis indoors. Stick to only what you need, and upgrade your setup as needed over time.
• Check your plants frequently and carefully: Check on your plants each day to make sure that they’re getting everything they need, including proper light, water, temperature, and humidity levels. Look at the stalks, stems, leaves, and buds carefully to make sure they’re not showing signs of disease or insect-related issues.

The bottom line: In states where it’s legal, growing cannabis indoors can be worth the effort

Growing cannabis indoors can be daunting at first, but over time, it can save you money and allow you to grow strains that can’t be found in your local dispensaries.

The key to growing cannabis indoors is buying the right equipment, finding high-quality seeds from a reputable source, and taking the time to give your plants the right environment so that they can thrive.

In some states, having a medical cannabis card allows you to grow more plants per household than recreational users. To start the process of getting your medical card, contact a Leafwell provider today.

Resources

• Glandular trichome development, morphology, and maturation are influenced by plant age and genotype in high THC-containing cannabis (Cannabis sativa L.) inflorescences. https://pmc.ncbi.nlm.nih.gov/articles/PMC10071647/
• Impact on nitrogen nutrition on Cannabis sativa: An update on the current knowledge and future prospects. https://www.mdpi.com/1422-0067/20/22/5803
• The effect of light spectrum on the morphology and cannabinoid content of Cannabis sativa L. https://pmc.ncbi.nlm.nih.gov/articles/PMC8489345/

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