How to grow marijuana seeds indoors: The complete indoor cannabis grower’s guide

Growing marijuana seeds indoors gives you full control over every aspect of your cannabis plant's life—from germination to harvest. With the right environment, quality seeds, and a solid setup, you can grow potent, high-yielding cannabis all year round. Indoor growing also keeps your grow private, secure, and protected from outdoor pests or weather risks.

In this comprehensive guide, you’ll learn how to grow marijuana seeds indoors step by step. We’ll cover everything from choosing seeds and setting up your grow room to lighting, nutrients, training techniques, and when to harvest. Whether you're starting your first indoor grow or leveling up your current setup, this guide is built to deliver success—especially when using premium genetics from Mavericks Genetics.

Why grow marijuana seeds indoors?

Indoor growing has several advantages over outdoor cultivation:

• Total control over temperature, light, and humidity
  
  

• Year-round growing regardless of season or weather
  
  

• Stealth and privacy for personal or legal discretion
  
  

• Fewer pests and lower risk of disease
  
  

• Optimized results through environmental tuning
  
  

While indoor growing requires more equipment and planning than outdoor cultivation, the return on investment—especially in quality and consistency—is often worth it.

What you need to grow marijuana indoors

To get started, you’ll need a few essentials:

Seeds

Choose feminized or autoflowering marijuana seeds from Mavericks Genetics, depending on your grow goals.

• Feminized seeds grow only female plants (no wasted space)
  
  

• Autoflowers are quick, compact, and beginner-friendly
  
  

Grow space

Options include:

• Grow tent
  
  

• Grow box
  
  

• Spare closet or room
  
  

Make sure the space is lightproof and allows for proper airflow and odor control.

Basic equipment

• LED or HID grow lights
  
  

• Carbon filter + inline fan for odor and ventilation
  
  

• Thermometer and hygrometer
  
  

• Timers for lights
  
  

• Oscillating fan for air circulation
  
  

• Grow pots (fabric or plastic)
  
  

• Growing medium (soil or coco coir)
  
  

• Nutrients and pH test kit
  
  

Step 1: Germinate your marijuana seeds

Before planting, germinate your seeds using a method that gives you control and visibility.

Recommended: Paper towel method

1. Dampen two clean paper towels with filtered water.
   
   

2. Place your seeds between them on a plate.
   
   

3. Seal inside a ziplock bag or container.
   
   

4. Store in a warm, dark place (70–80°F).
   
   

5. Taproots should appear in 1–5 days.
   
   

Once the taproot is ¼–½ inch long, you’re ready to plant.

Step 2: Choose your growing medium

You can grow indoors in several media, but most home growers choose soil or coco coir.

Soil (organic)

• Easier for beginners
  
  

• Contains beneficial microbes
  
  

• Slower nutrient absorption (forgives mistakes)
  
  

Use a light, well-draining mix with pH around 6.0–7.0.

Coco coir (soilless)

• Fast growth rates
  
  

• Precise nutrient control
  
  

• Requires more frequent feeding and pH management (5.5–6.5)
  
  

Step 3: Set up lighting

Lighting is the most important factor in your indoor grow. More light = more bud, when used correctly.

Common light types:

Vegetative stage: 18/6 light schedule
Flowering stage: 12/12 light schedule

For LEDs, aim for 30–50 watts per square foot of grow space.

Step 4: Manage temperature, humidity, and airflow

Temperature

• Seedling stage: 70–80°F
  
  

• Vegetative stage: 72–85°F
  
  

• Flowering stage: 65–80°F
  
  

Humidity

Use a humidifier, dehumidifier, or ventilation system to maintain levels.

Airflow

• Install an oscillating fan to strengthen stems and prevent mold.
  
  

• Use carbon filters to manage smell and pull fresh air into your tent.
  
  

Step 5: Feed and water your plants

Your feeding routine depends on your growing medium.

In soil

Use organic or synthetic nutrients designed for cannabis:

• Veg stage: High nitrogen (N)
  
  

• Flower stage: High phosphorus (P) and potassium (K)
  
  

Feed every 1–2 weeks and always check pH of water/nutrient solution (soil target: 6.0–7.0).

In coco

Feed nutrients every watering at lower concentrations. Keep pH between 5.5–6.5.

Step 6: Training your plants for indoor yields

Training techniques help maximize space and light exposure.

LST (low stress training)

• Bend and tie down branches
  
  

• Increases bud sites and airflow
  
  

Topping and FIMing

• Remove the main shoot to encourage multiple colas
  
  

• Use in early vegetative stage
  
  

SCROG (screen of green)

• Train branches under a mesh screen
  
  

• Creates a flat canopy for even light distribution
  
  

Step 7: Flowering and the light switch

When you're ready to flower (for photoperiod strains), switch your light schedule to 12 hours on / 12 off.

Signs of flowering:

• Pistils (white hairs) begin to appear
  
  

• Vertical growth slows
  
  

• Bud sites form at branch nodes
  
  

Autoflowers will flower automatically, usually 3–5 weeks after sprouting.

Step 8: Monitoring trichomes and harvesting

When to harvest:

Use a magnifying glass or jeweler’s loupe to check trichomes:

Harvest when most trichomes are cloudy with some amber.

Step 9: Drying and curing your buds

After harvesting:

1. Trim fan leaves
   
   

2. Hang branches in a dark room (60°F, 50% RH)
   
   

3. Dry for 7–10 days (until stems snap)
   
   

4. Cure in glass jars for 2–4 weeks
   
   

5. Open jars daily during week 1 (“burping”)
   
   

Best strains to grow indoors

When space, stealth, or time is limited, these seed types shine:

• Autoflower strains – Quick, compact, low-maintenance
  
  

• Short-flowering indicas – Bushy and ideal for tents
  
  

• Mold-resistant hybrids – Great for humid spaces
  
  

Explore top indoor genetics hand-selected by Mavericks Genetics breeders.

Troubleshooting common indoor growing issues

Final thoughts: Growing marijuana indoors offers control and quality

Growing marijuana from seed indoors allows you to create the perfect environment for each stage of your plant’s development. With the right setup, care, and genetics from Mavericks Genetics, you can produce potent, clean cannabis harvests at home, year-round.

Whether you're just starting or scaling up, this guide is your foundation for indoor growing success.

Ready to start your indoor grow?

Shop the full collection of high-performance indoor cannabis seeds at Mavericks Genetics and choose the perfect strain for your grow space and experience level. All seeds are backed by elite breeding, high germination rates, and guaranteed results.