Best Pot Size For Growing Autoflowers

Choosing the right pot size for autoflowers is like preparing for a competition. Your pot size determines how well your autoflower seeds will grow and the quality of your autoflower yields.

Although there are several pot sizes used in general and even cannabis cultivation, autoflower growers have settled on the small pot size range of between 6 to 15 liters for growing autoflowers.

But don’t jump your horses yet. Choosing just any pot size within that range based on gut feeling or “because you feel like it” isn’t a very solid move. There are steps to choosing the right pot size for autoflowering seeds.

In this Seed Fair guide, we explore all you need to know about choosing the best pot size according to the size of your autoflowers and what other factors you should consider before deciding on the best pot for autoflowers.

Why Pot Size Matters for Autoflowering Cannabis

Pot size matters a lot for autoflowering cannabis because your autoflower can only grow as well as its pot allows. When deciding what pot size for autoflowers, you’d need to apply the Goldilocks principle: not too small, not too big.

Growing your autoflowers in a pot too small can leave just as sour a taste as growing them in a very large pot; bigger isn’t always better when choosing the right pot size.

Another reason why choosing the right pot size matters for Autoflowering cannabis is that Autoflowers hate transplanting. Uprooting then for any reason, even for a transplant because the initial pot size was too small, can get them seriously stressed and lead to dismal yields.

So, when deciding on the best pot size for autoflowers, it is important to project the final size of the cultivar. This will help you determine what pot size works best for your entire autoflower life cycle; what pot size can take your cannabis plant to the finish line.

Best Pot Size for Small and Dwarf Autoflowers (6–8 liters or 1.5–2.1 gallons)

The best pot size for growing small and dwarf autoflowers, such as Lowryder autoflower, are 6 to 8 liters or 1.5 to 2.1 gallon-sized pots. Some traits that make this pot size range suitable for planting weed seeds of small and dwarf plants include:

1. Their small size: Small and dwarf autoflowers need just enough space for their root structure. Growing these plants in overly large pots could lead to root rot or nutrient deficiency since their roots cannot access all the nutrients in the substrate.
2. Their small yields: Small and dwarf strains will produce small yields when it reaches the time to harvest autoflowers unless you use specific plant training techniques, like the Sea of Green method. But to use the Sea of Green technique, you need small-sized pots.

Ideal Pot Size for Medium-Sized Autoflowers (9–10 liters or 2.3–3 gallons)

Medium-sized autoflowers are like the “just right” of the Goldilocks cartoon. These autos need just enough space to extend their roots a little further than what small-sized pots can offer, or else you will stunt your autoflower yields.

When choosing the ideal pot size for medium-sized autoflowers, like Blueberry Auto, you want to go for pots within sizes 9 and 10 liters or 2.3 and 3 gallons. Pot sizes within this range provide adequate space for your medium-sized autos to extend their roots without the risk of overwatering or dehydration or nutrient deficiency.

Ideal Pot Size for Big Autoflowers (11–15 liters or 3–4 Gallons)

Big-sized autoflowers need big pots. Without large enough pots, large autoflowers, like Gorilla Glue Auto or Strawberry Cough, will become rootbound, dehydrated, and die—or best case scenario, produce measly yields.

Choosing the right pot size for big autoflowers, stay within pot sizes between 11 and 15 liters or 3 to 4 gallons. Pots this size are spacious enough to contain the roots of big plants and hold sufficient substrate for proper nourishment. They are also stable enough to support the yields of big-sized autos and whatever plant training technique you might need to employ with autoflowers this size.

Best Pot Size for SOG or ScrOG

Sea of Green

The Sea of Green plant training technique is quite the famous low-stress training method for autoflowers among cannabis growers of small cultivars. Growers especially love this technique because it allows them to grow numerous plants per pot and numerous pots per space to increase autoflower yields.

Two important factors with the Sea of Green method include small pots and maximizing space. To properly apply the Sea of Green method, you need small-sized pots, between the range of 4 and 6 liters.

 

Avoid planting seeds or putting plants too closely together in the Sea of Green method to minimize crowding and competition. You should keep a plant or seed spacing of about 6 to 12 inches to enable even resource distribution in your grow space.

Screen of Green

The Screen of Green method is quite the opposite of the Sea of Green method. With the Screen of Green method, larger-sized autos are the ideal choice.

When choosing the best pot size for the Screen of Green method, you need a stable, sturdy pot that can support lateral branching and heavy buds because you’ll be doing a lot of horizontal tie-downs. Without a stable, sturdy pot, your entire set-up is likely to fall over as your autoflower grows bigger.

So, while there is not one agreed pot size for the Screen of Green method, we advise going with pot sizes between 10 and 15 liters.

3 vs 5-gallon pots for autoflowers

3 or 5-gallon pots for autoflower? Some growers choose 3-gallon pots for growing autos. Others choose 5-gallon pots. Even if we wanted to select what pot size to grow autoflowers in, we couldn’t tell you what size of pot you should use.

The right pot size depends on the size and yield potential of the cultivar. Thus, before you choose between a 3-gallon pot or a 5-gallon pot, here are a few key differences between these two pot sizes:

	3 Gallon Pots	5 Gallon Pots
Soil Capacity	Can hold less substrate than a 5-gallon pot. Preferred for small-sized autos.	Can hold larger amounts of substrate. Preferred for larger-sized autos
Root Space	Lesser dimensions to adequately support the needs of small-sized autos	Greater dimensions for more root space for large autos.
Water Retention	Requires less watering with the right cultivar. Prone to overwatering and drying out.	Requires more watering with the right cultivar. Prone to drying out due to the larger surface area.
Mobility	Can be easily moved around.	Much heavier to move around.
Portability	Suitable for small spaces.	More suited for large spaces.

 

Other Important Things to Consider When Choosing a Container for Autos

Pot size matters when choosing a container for autos. But, some other factors also matter when choosing a container for autos. Some of these factors include:

Drainage

When choosing a container for autos, you need a well-draining pot, whether you have selected a terracotta, ceramic, or fabric pot. A poorly draining container could lead to a waterlogged substrate and eventual root rot or your substrate drying out, heat stress, and eventual wilting of your entire plant. If you find your desired pot doesn’t have enough drain holes, we recommend going for a different pot or you can try to be more adventurous and attempt making drain holes yourself.

P.S.: Choosing a substrate with good draining capability is also vital.

Root Zone Capacity

Obeying the Goldilocks rule when growing autoflowers means choosing a container with adequate root zone capacity for your autos. Autoflowers need enough room to extend their roots and establish their structure but not too much room that they struggle to reach nutrients and other essential resources contained in their substrate. Plus, when your autoflower keeps stretching its roots to reach nutrients, it negatively affects the development of other vegetative parts, like the leaves, stems, etc.

Color (surprisingly!)

Choosing the right color when choosing a container for autos goes beyond aesthetics. Darker-colored pots are great heat absorbers. Growing autoflowers in an extremely hot climate and using a dark-colored pot can lead to heat stress. Dark-colored pots for growing autoflowers are mostly best advised when you need to keep the substrate warm.

On the other hand, lighter-colored pots are excellent heat reflectors. They are ideal for growing autoflowers in hot climates. Light-colored pots keep the substrate cool.

Traditional pots vs. Fabric pots

Traditional pots range from the standard plastic growing pots to ceramic pots. These pots are relatively affordable, readily available, and are some of the most commonly used pots in cannabis cultivation.

However, traditional pots are quickly going out of fashion. Fabric pots are starting to make an appearance as the best pots for growing autoflowers and other cannabis strains for many reasons.

Some advantages of fabric pots over traditional pots include:

1. Fabric pots are more breathable than most traditional pots and so improve aeration.
2. Most fabric pots are lightweight and easy to move around.
3. The breathable materials of fabric pots support unique functions, like air root pruning and bottom watering.
4. Fabric pots have excellent drainage capabilities and temperature control.

Some areas traditional pots still win over fabric pots include: 

1. Most traditional pots have better water retention than fabric pots.
2. Some traditional pots are more affordable than fabric pots.
3. Most traditional pots have faculties that prevent water from leaking out their bottoms or sides to the floor when growing indoors.

A Couple of Words about Smart Pots

Smart Pots are quite like fabric pots, but they are superior to fabric pots. These pots offer several, if not all, of the loved features of fabric pots and more. Because they are made from synthetic fibers, such as polyester and polypropylene, smart pots are more durable than several fabric pots. Some smart pots can last as long as 10 years.

Conclusion

Choosing the best pot size for autoflowers requires adequate research into the cultivar you hope to grow. Remember, autoflowers hate transplanting, so the best way to grow autoflowers is to start them in their final containers.

But, before settling on a pot size, ensure the chosen container also ticks off all necessary boxes in your checklist of the best pot for growing autoflowers.

FAQ

Do autoflowers need big pots?

The pot size your autoflower needs depends on the potential size of your plant. Small-sized plants require small-sized pots. Bigger-sized autoflowers require bigger-sized pots.

Can I transplant an autoflower to a bigger pot if mine is too small?

Yes, you can, but it is risky. Transplanting autoflowers stresses your autoflower and risks a percentage of your yields.

Can I use a 3-gallon pot for outdoor autoflower grow?

Yes, you can use a 3-gallon pot for outdoor autoflower grow. How well-suited your pot size is to your autoflower depends on the size potential of the autoflower.

How deep should I plant a seed?

Most cannabis growers recommend planting a seed about 0.5 to 1 inch deep into the substrate. At this depth, the seed is deep enough to establish its roots but close enough to the surface to emerge easily.

Please note: Keep the substrate moist at the germination stage to make it easier for the seedling to push through.