Choosing a Pot Size for Autoflowers

Growing is an art of science, and some methods achieve better results than others. There are different sizes, types, and colors of pots to consider, and it can be intimidating to know if you’re making the right choice. And with good reason. Your choice of an auto flower pot can impact your plant’s growth.

We’ll talk about the best pot size for autoflowering seeds and give some advice on choosing the best pot for growing high-producing autoflowering plants. 

What to consider before planting autoflower seeds 

Before planting your autoflowering seeds, it’s essential to consider both how you grow your plants and your goals. The best pot size for autoflowering seeds depends on what is available to you. Use a smaller pot size if you plan to grow multiple plants in a smaller area, and use a tent. 

Larger pots will give your plants room to grow and spread their roots, ultimately leading to a larger yield since they can take up more nutrients. Additionally, consider planting your seeds in the same pot you plan to harvest; this will minimize transplanting stress and promote a healthy root system. Your space size and the kind of plants you want to grow should also be a factor when choosing your autoflower pot. 

Factors to consider when growing autoflowering cannabis  

Root zone or root bound of your cannabis plant

One of the essential nutrient uptake systems in the cannabis plant is its roots. Gardners have always used the quote, “the bigger the roots, the bigger the fruit.” This quote rings true for cannabis as well since the root zone is the most efficient area for nutrient absorption. 

It’s crucial to optimize for the best size pots for autoflowers since they have a shorter vegetative cycle, making for a tighter timeframe to get the root growth correctly.

Color of the pots you grow your weed in matters

Color is not typically front of mind when thinking about the best size pots for autoflowers, but it does play an essential role in the amount of heat the roots receive. If you are growing in a cooler area and need the roots to stay warm, use black pots. Conversely, it may be best to use white pots to deflect the sunlight if you’re in a hot place. 

Match the shape of your pot according to your growing method

Typically, pots will either be round or square. Square-shaped pots are best suited for space optimization or for techniques like SOG, where you can cluster multiple single-stalk plants together. Rounded pots are an inherited trait from the early days of clay pots being thrown on a wheel, though they are currently still used due to their ease of cleaning. 

Drainage is important for your rootzone

Drainage is critical when considering autoflower pots since it affects the plant’s ability to uptake nutrients and adequately aerate the root zone. If the pots you use don’t have sufficient drainage, use a drill to put holes in the bottom of your pot, it will make all the difference in your end product. 

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Choosing the right grow medium to match your potting

For most home and novice growers, grow mediums like soil and coco coir are the usual choice since they have less oversight than other methods. Rockwool, clay pellets, hydroponic, and aeroponic methods are considered more advanced and don’t need the same type of potting as mediums like soil and coco. 

Are you planning to train your autoflowers?

Pot size for autoflowers can be an essential factor when considering how to train your plants. Some training methods call for growing autoflowers in 2-gallon pots, whereas others may call for larger 4-5 gallon pots.

If you’d like to know more about pot size and autoflower training, read our article on how to maximize your autoflower yield.   

Pot sizes for the Sea of Green method (SoG)

When dealing with the Sea of Green method, you should use smaller pots to maximize volume. Growing autoflowers in 2-gallon pots (or 1-gallon) square pots would be an ideal choice for this method since it allows you to cluster the autoflowers together. 

Pot sizes for the Screen of Green (SrcOG)

The Screen of Green method allows for larger plants in your garden since this training spreads the stalks of the plant across to allow for airflow and light penetration. This low-stress training method is perfect for indoor growers looking to use fewer plants but to maximize their canopy. This training method is one of the few techniques you can do with autos with minimal stress to the plant. 

The different types of autoflower pots

With so many different types of potting available, what choice should you make?

Fabric pots

Fabric pots have quickly become the most used material for potting in the world of cannabis due to their positive effects on the root zone. Fabric pots for autoflower help with allowing the roots to breathe on all ends, drain correctly, and are a soft material for roots to push against. 

Air pots

When it comes to aeration, Air Pots take the lead. These plastic pots have hundreds of holes and openings on the sides and bottom of the pot to expose the root zone to oxygen and gain beneficial aerobic microbes. If you’re willing to water frequently, Air pots are perfect for airflow and drainage capabilities.

Terracotta pots

Terracotta pots are ideal to use if you won’t be moving your plants much but are in a warmer environment. Terracotta can soak up and retain moisture, allowing it to keep cool in warmer climates. When using these pots, it’s best to drill holes in the bottom to allow for better drainage.

Plastic pots

Tried, and true, plastic pots are a great inexpensive, easy-to-clean option with various shapes. Ensure your plastic pots have drainage holes to prevent water logging and nutrient lockup. I recommend using 1-gallon square plastic pots when growing using the SOG method. 

Paint buckets

Cultivators have used a great “guerilla growing” prop, paint buckets, to make the most out of their equipment. Since paint buckets are not explicitly made for plants to be put in, you will want to drill drainage holes to ensure no water logging. 

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Cement pots

Cement pots can be a solid fixture for plants that last a long time and are more environmentally friendly than other potting options. I would not recommend using these as they are very cumbersome to move and could cause issues with your watering. If you are making your cement pots, follow a tutorial on properly cleaning them to make them plant ready.

Smart pots 

Smart pots are a specific brand of geo-textile pots made of a combination of synthetic fibers (generally polypropylene and polyester). They are widely agreed in the industry to be the best pots and the best pot size for autoflowering seeds. 

Common autoflower pot setups

1-4 large size autoflower plants 

When looking to grow in larger pots, the ideal pot size is 2.5-4 gallons (10-15 liters) in fabric pots. If you’re working with a standard 1.37 x 1.37 meter (4.5 x 4.5 ft) tent, this will be ideal for spacing so your plants will get an even distribution of sunlight and ventilation.

Screen Of Green

Using larger plots to give your plants more space makes for an ideal canopy to use the ScrOG method of training. Trellis netting allows you to keep an even canopy and let your autoflowers have constant air movement and adequate light penetration. 

6-10 smaller plants

For an area fitting 6-10 smaller plants, we recommend 1.75-2.5 gallon pots. 2-gallons is the sweet spot for space optimization, and when combined with a 1.37 x 1.37 meter (4.5 x 4.5 ft) tent, you have the best size pot for autoflower plants indoor.

Best size container for indoor autoflower grows 

Indoor cultivation tends to produce smaller plants; 2 gallons is the best size pots for autoflower plants. Use plastic or fabric pots depending on your setup, with fabric pots ideal for ScrOGging and plastic pots suitable for SoG methods. Regardless of the pots you use, remember to have proper drainage under your pots and a saucer to catch the runoff water in to prevent the plants from soaking. 

Best size container for outdoor autoflower grows 

For outdoor growing, the best pot for autoflower is a 4-gallon to give the roots as much room as needed. If you are growing in a windy climate, it may be best to use a heavier type of pot, like cement or terracotta, that will anchor the pot. Drainage holes are still needed for outdoor plants, but the pot’s bottom will not require a saucer since it will drain into the land. 

There are various ways to grow your autoflowers, and multiple pots can suit different needs. If I were to put together my home grow right now, the best pot size for autoflowering seeds would be 4, 4-gallon fabric pots with trellis netting for a ScrOG. It’s crucial to prepare for your grow by selecting the correct pots. 

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FAQs

Are 2-gallon pots big enough for Autoflowers?

Yes! 2-gallon is the best pot size for autoflower cultivars growing indoors. 2-gallon autoflower yield is the sweet spot for most autoflower growers. Practicing SOG autoflowers in 1-gallon pots may be ideal, but typically 2 gallons and above will work best for your plant’s root zone.

Can you grow two autoflowers in one pot?

Yes, but remember to size up your pot if you plan to grow multiple plants in one pot. A 6-10 gallon pot will make for the best space for multiple plants; this will make the pot similar to a soil bed. Growing 2 autoflowers in one pot is a method I’d recommend if you’re tight on space.

How much soil does an autoflower need?

Allow for a knuckles-length space from the lip of the pot to finish where you put your soil. Make sure not to press down the soil too much, as it will create difficulties for the plant’s root growth.

Do Autoflowers take longer in bigger pots?

No, an autoflower will veg and flower at the same rate regardless of the pot since it isn’t a photoperiod plant. Regardless if they are in a 1-gallon or 10-gallon pots, autoflower plants will grow at the same rate.

Is there a reason to do SoG in larger pots?

If you are growing regular photoperiod plants, there may be merit to using larger pots and vegging the plants longer, but with autoflowers, there is no reason to use larger pots when doing SoG.

Cited sources:

• (2019). Root Zone Heating & Cooling of Cannabis. Retrieved from http://rootssat.com/wp-content/uploads/2019/02/Roots-Heating-Cooling-Cannabis-FINAL.pdf
• Zheng, Y. (2016). Root zone environment management in container crop production. Proc. for the Veg., potato, greenhouse, small fruit & Gen. session. Mid-Atlantic Fruit & Veg. Convention, Hershey, PA. p.111-112. 
• Zheng, Y., L. Wang, and M. Dixon. 2007. An upper limit for elevated root zone dissolved oxygen concentration for tomato. Sci. Hort. (Amsterdam). 113:162–165.
• Caplan, D., M. Dixon, and Y. Zheng. (2018). Propagation and Root Zone Management for Controlled Environment Cannabis Production. The Atrium 52:1796– 1803.