Growing cannabis indoors is extremely rewarding and a very common practice among many growers. Some grow indoors out of necessity due to climate, and others grow indoors in large greenhouses with sophisticated equipment to maintain total control.

Cannabis plants, like all plants, thrive outdoors with ample sunshine, rain, and wind to provide nutrients, strength, and resilience to plant leaves and stems. When growing indoors, it is important to replicate nature as much as possible.

Tips for Growing Fat Buds and High-Yield Indoors

Here are some of the most important tips to grow healthy cannabis plants with big, healthy buds and maximum yield indoors.

Maintain the Right Temperature and Humidity Levels

It is extremely important to keep your temperature and humidity at cannabis-friendly levels; this means an indoor temperature of 70° to 80°F and a humidity level of 40 to 60%. You can use a combo thermometer and hygrometer to know your current indoor conditions at all times and make adjustments when needed.

If the temperatures get too cold, your plants will get stressed and stop growing; if it’s too hot, plants will start to wilt. Plants thrive outdoors when the temperature is around 75° to 85°F during the day and at around 70°F at night when it’s dark.

Make sure the humidity level is reduced to about 50% when cannabis plants start to flower. This provides enough moisture for plant growth but helps to prevent the development of mold and loss of buds due to mold and mildew. The best way to reduce humidity in your grow room is with proper ventilation with outside air.


Lights and Timing

You should use a timer on your lights to recreate the natural summer and fall seasons. The vegetative stage occurs during the summer when plants receive a lot of daylight. When growing indoors, you should set your lights on your plants a good 18 to 20 hours per day during the vegetative stage. The vegetative stage typically lasts about 3 to 4 weeks, although can vary based on your seed type and strain.

During autumn, which is the flowering stage, lighting must be reduced to replicate the fall season, which is what triggers your plants to switch from vegetative to flowering stage (unless you’re growing with autoflower seeds that switch to flowering based on time, rather than light). When it’s time to switch to the flowering stage, your cannabis plants need 12 hours of light and 12 full hours of darkness. The flowering stage can take 8 to 9 weeks and, again, can vary based on seed type and strain. Also, plan on a few weeks for drying and curing, and keep notes with a calendar for reference.

The type of lighting used is also important. LED and compact fluorescent bulbs produce ample light for plant growth, although High Intensity Discharge (HDS) lamps such as High-Pressure Sodium (HPS) and Metal Halide (MH) lamps are preferred for growing cannabis indoors. HID lamps come in a variety of wattages and are quite versatile to provide essential illumination for plants to thrive indoors. These lamps can get hot, so you want to maintain good ventilation in your grow room.

Keep your lights about 18 to 36 inches above the top of your plants to be careful not to burn them. Using a mixture of spectrums is ideal although some growers believe that MH bulbs help for node development during the vegetative stage while HPS lamps mimic the glow of sunshine in the fall during the flowering stage. If your grow tent is 3’ x 3’, or 4’ x 4’, you can get ample lighting coverage with about 400 to 600 W. If your space is closer to 5’ x 5’, you want at least 1000 watts to properly light your grow space. Learn more about how many plants you can grow in your tent.

Use the Right Nutrition for Each Plant Stage

Cannabis plants need macronutrients like all other plants, which include nitrogen, phosphorus, and potassium, referred to as N-P-K, in the right ratios at the right times.

You want to direct plant energy towards growing dense leaf canopies and stout stems during the early stages, which sets the stage for bigger buds. Nitrogen is critical to spur green growth during the vegetative stage. Cannabis plants require more phosphorus as they mature and reach the flowering stage. Phosphorus is also abundant in bone meal, a natural plant supplement, which can be given to your cannabis plants right before they start budding. If using bonemeal, check the pH of your nutrient solution and bring down the acidity when needed.

Train Your Plants; Learn about Low-Stress Training

Learning how to train your cannabis plants is one of the most important ways to increase yield, whether growing indoors or outdoors. Cannabis is an amazing plant and proper training can significantly increase the production of big, healthy buds. Many growers perform what is called topping, or pruning, although another technique exists, which is called Low Stress Training (LST). This is often preferred for indoor growing as topping and clipping shoots require a significant recovery time.

LST involves bending the top branches, which allows the primary light source to reach more surface area under the top leaf canopy, and using string or wire to tie the bent stems to two thin bamboo sticks to keep them in place. This practice allows growers to control the height and shape of plants and produce bigger yields in small spaces.

Ventilation and CO2

Carbon dioxide is a critical component for photosynthesis to occur. In nature, the atmosphere contains about 400 PPM of CO2, which can drop significantly in a closed indoor space. Maintaining high CO2 levels is necessary for cannabis plants during the budding stage and will ramp up growth rate and yield. You can use a simple and inexpensive CO2 generator and ramp up CO2 to as much as 1500 ppm to help your plants with successful photosynthesis, the process that converts light into growth.

Additional Tips for Growing Cannabis Indoors

Some additional tips practiced by successful indoor growers are to:

  • Make sure your containers are big enough to support bigger plants with ample room for root development to result in high-yield
  • Use adjustable hangers to support your lights so you can move them as needed
  • Rotate your plants daily to make sure all leaves get adequate light
  • If using tap water, leave it out overnight to help the chlorine dissipate prior to adding your nutrients and feeding your plants
  • Support branches with the trellis system or plant stakes

Growing cannabis indoors is an extremely rewarding practice, one that you can have fun with all year round, and with the right equipment, you can keep it somewhat hidden or secretive for added security. Follow these tips and start every grow with high-quality cannabis seeds from a reputable seed company like Mosca Seeds.

Mosca Seeds offers a wide selection of high-quality, award-winning cannabis seed types and strains with over 15 years of cannabis breeding experience. We follow quality cannabis genetics practices and produce stellar seeds for high growth and maximum yield. Check out the Seed Bazaar today and get growing with these tips for growing cannabis indoors.