How to Grow Autoflowering Cannabis Seeds

What Is Autoflowering Cannabis?

Autoflowering cannabis, also called cannabis ruderalis or automatic cannabis, is a plant species that automatically produces flowers once it reaches a certain size. Unlike cannabis sativa and cannabis indica, cannabis ruderalis does not require a 12-on, 12-off light cycle. However, cannabis ruderalis alone contains little to no THC. Growers began cross-breeding the strain with cannabis sativa, cannabis indica, or both to produce a cannabis strain that is high in THC, while also automatically flowering under 24 hours of light. 

How Do Autoflowering Cannabis Seeds Work?

Autoflowering cannabis seeds will flower automatically within two to four weeks. Growers do not need to hassle with a light schedule to ensure that the plant produces flowers. Instead, autoflowering seeds can be left with 24 hours of light. 

Autoflowering vs. Normal Growth Methods: Pros & Cons

There are many benefits to choosing autoflowering cannabis seeds over normal growing methods, including:

  • Less time required to grow 
  • More convenient without a light cycle 
  • Many varieties to choose from, including high CBD, high THC, and a balance of both
  • Diverse terpene profiles available
  • Compact size
  • Resilient to mold and pests
  • Fewer nutrients needed

While autoflowering growing is the preferred choice for many, there are some disadvantages when comparing cannabis ruderalis to traditional cannabis, including:

  • Lower yields
  • Higher lighting expense
  • Generally lower THC content


Growing Autoflowering Cannabis Plants

How to Start Autoflower Seed

Autoflower seeds are great for beginners. However, there are still some things to consider before growing, including:

  • Location: Autoflowering seeds can survive just about any climate. If you are growing your plants outdoors, you will need to ensure that the seeds receive at least 12 hours of sunlight each day, with 16 hours being ideal. Autoflowering seeds can also be grown inside with the right hydroponics setup and can be left under 24 hours of light. 
  • Soil: Soil for autoflowering cannabis should be light and airy to ensure that the roots can easily penetrate the ground. If you’re choosing a soilless growing method, you will want to use a nutrient-rich solution to give your plants what they need to grow. 
  • Lighting: Autoflowering cannabis will grow despite a lack of light. However, for the best results, you should use grow lights to give the plants as much light as possible. 

Once you have these key things prepared, you can begin to grow your autoflower plant. Here’s what to expect during the first several weeks:

  • Germination: Autoflower cannabis seeds will germinate in potting soil in about three days. During this time, the seed begins to root and leaves begin to appear. Once germinated, you can transplant the plants if necessary.
  • Seedling phase: During the seedling phase, the autoflowering plants start using light to create energy. Consistent exposure to light is critical at this phase.
  • Vegetation: Once your plant has started growing, you can look at its environment to enhance the process. Focus on keeping the plants watered, controlling the temperature, and providing enough light. 
  • Flowering: At about week five, the plants will form buds that will later become flowers. During this phase, you will want to lower the indoor humidity and watch for potential mold. 

Taking Care of Your Autoflowering Cannabis Plant

Once your autoflowering plant has started growing and flowering, you can focus on maintenance and taking care of the plants. This involves regularly checking the humidity, light, and temperature of the growing environment, inspecting the leaves for any signs of pests or lack of nutrients, flooding the soil to flush out old chemicals, and trimming the leaves from below the bottom nodes. 

How to Tell If Your Autoflower Is Ready for Harvest

It can take nearly three months before an autoflower cannabis plant is ready for harvest. When it’s time, the majority of the flower’s trichomes will be white and pistils will be red/brown.

Hydroponics Systems for Autoflowering Cannabis

Hydroponics systems can be used to grow autoflowering cannabis. Hydroponics involves growing plants without soil and can involve various techniques, such as ebb and flow, drip systems, and nutrient film techniques. Instead of soil, hydroponic systems require nutrient-rich, oxygenated water. The solution is given directly to the plant’s roots, eliminating the need for the plant to use their energy to search through soil for what they need. 

The Green Room has several different commercial and residential growing systems to choose from to assist your autoflowering cannabis plants. 

Benefits of Hydroponics for Autoflowering Cannabis Seeds

With hydroponics, you can further enhance the efficiency of autoflowering cannabis seeds. Some benefits of choosing hydroponics include:

  • Roots receive more nutrients and oxygen
  • Better control over growing conditions
  • Faster growing plants
  • Higher yields 

Start Growing with The Green Room

Ready to start growing autoflowering cannabis seeds? The Green Room has the hydroponics system you need to get started. 

Contact us today. 

Frequently Asked Questions (FAQ)

How Tall Do Autoflowers Get?

Autoflower cannabis plants can grow to be 50–70 cm tall, with some reaching 100 cm. The plant’s smaller size makes it ideal for growing indoors. 

What Should the Light Schedule for Autoflowers Be?

Autoflowers are known for their ability to automatically flower without needing 12 hours of light followed by 12 hours of dark. While some growers still choose to set a light cycle with at least 16 to 18 hours of light, others allow 24 hours of light to maximize growth. 

Autoflower vs. Photoperiod: What’s the Difference?

Photoperiod plants flower when they experience a change in light cycle. This is unlike autoflowering plants which automatically flower when they reach a certain size. Photoperiod plants typically take longer to harvest but produce bigger yields. 

Are Autoflowering Seeds Always Female?

Autoflowering plants can be feminized, or bred to produce only female plants. The result is completely natural female seeds that can produce more usable parts of the plant than male plants.