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Autoflower Pot Size Guide for Indoor and Outdoor

Curious what the best autoflower pot size is for your grow? Check it out! Tips for pot sizes when growing indoors and outdoor Last updated 06/12/2022

    Choosing a pot size can greatly affect your autoflower strain's yield potential. Go too small, and you risk stunting the crop; go too large, and the soil may dry out. Here we look at how to pick the perfect size for your home’s autoflower setup indoors and outdoors. We’ve included some top tips on drainage and container types too to help you get off to a racing start.

    What size pot for autoflower?

    Once you've received your (Weedseedsexpress) seeds and have got to work germinating them, you'll need to think about potting your autoflower plant. The first thing to know is that pots come in all shapes, sizes, styles and materials. Whichever pot you choose depends on your strain's ideal height and the restrictions of your growing setup/space. If you're opting for an autoflower SCROG setup with many plants in a tightly-knit space, smaller pots are perfect. For grander operations like ScrOG where you encourage your plant to expand and grow, you'll need a much larger pot.

    In general terms, the larger the pot, the more space available for future growth. If you want to grow a tiny plant in a discreet cupboard or corner, you’ll need a smaller pot to encourage compact growth. What’s more, if you’re potting your plant outdoors, you’ll require a larger pot than one indoors. Another quick note here is that while re-potting a plant into a larger pot as it grows is fine, autoflowers benefit from starting in the pot you want them to finish in. That’s because autoflowers are quick growing and flower on their own, leaving less room for error when adjusting a plant to a new soil environment.

    Best pot size for autoflowers

    Autoflowers are slightly more complicated than photoperiod strains when it comes to choosing a pot because they grow rapidly without relying on light conditions. You have to then think not only about how long your plant will grow for, which is usually within 3 months, but also how big it may grow. Luckily, you’ll find all this genetic information on each Weedseedsexpress strain profile.

    Indoor grow

    Simply put, very small indoor autoflower plants can be grown in pots of between 6.5 to 9.5 liters (or 1.75 to 2.5 gallons). Choose this for plants projected to grow just 40 or 50 cm in height or for compact SOG setups. Larger indoor setups for plants over 50 cm do well in up to 11.3 liter (or 3 gallons) pots.

    Outdoor grow

    Outdoor growers can expect larger heights and so require bigger pots. Opt for anything between 10 and 15 liters (2.65 to 4 gallons) with an outdoor plant, depending on the height. While larger pots encourage greater growth, there is a shorter growing period on autoflower strains – so don’t waste your money on pots bigger than 15 liters.

    What should a pot for autoflowers comply with?


    Drainage is one of the most important aspects for maintaining soil quality and affecting cannabis growth. It’s especially important for short-growing autoflower strains, as it promotes the exchange of air through the plant’s roots. This allows the growing medium to dry properly, aiding the growth rate of the plant itself. Plastic containers are among the most popular pots on the market. They often do not contain drainage holes and therefore need a little tweaking to work well. These include drilling holes or adding clay balls to the bottom of the pot to allow the water to drain slowly. Without proper draining, your plant can become waterlogged, reducing the amount of oxygen absorbed by the roots and stunting its growth. The tell-tale signs of poor drainage are brown, wilting leaves. Some pots work better at drainage than others, as you’ll see below, so try to opt for one of those for the best success.

    Dark color

    We often want our plants to look nice. Before you settle on a color, know that it can make a difference to your plant’s actual growth. Darker colored pots are better at absorbing light and retaining heat for the soil. This is a must if you’re planting in cooler temperate conditions or are keeping your plant in a greenhouse or windowsill. If you’re growing in a very warm climate, this won’t be an issue and can even over-stress your plant’s roots.

    Pot should be clean

    It may go without saying, but your pot should always be clean when potting. If you’re using an old pot, residue from its previous inhabitant, like disease-carrying pathogens, can still be present. If you plant your new seeds in these unsterilized containers, they may get infected and possibly die young. As autoflowers grow so quickly, there's little room for these basics errors, which can stunt growth and diminish yields. Luckily, it’s very easy to get your pot in good shape. Take some kitchen sponges and a wire/mesh brush to get started. First clean with dish soap, then sterilize with bleach or vinegar solution (the organic method) before rinsing and drying for use.

    Enough space for optimal development

    This one is crucial for increasing your plant’s potential yields. Without the proper sized pot, you’re limiting your cannabis and preventing it from reaching its resinous potential. It’s always best to err on the larger side of your plant’s prospective growth, as long as you have the space.

    This gives it plenty of soil area to dig deep and flourish. The deeper your plant’s roots can develop, the bigger your cannabis plant will get. Too much space, however, will be a waste of nutrients and water.

    Best pots for autoflowers

    While you can’t go too wrong with a typical plastic pot as long as it has basic draining holes, not all pots are created equal. The following three pots are among the best pots you can pick up due to their improved aeration and drainage. Whichever one you pick is entirely up to you.

    You can even experiment with multiple pots side-by-side to see which gets the best results. It all comes down to how well your plant's roots are treated. You want to keep your roots hydrated, nourished and healthy.

    • Fabric containers
    • Terracotta pots
    • Air Pots

    Fabric containers

    Fabric pots are among the best options out there as they allow roots to breathe, boosting growth and promoting higher yields. With fabric pots, your plants are more likely to develop secondary roots to absorb nutrients. Unlike root-bound plastic plant pots, fabric pots prevent roots from circling when they reach the edge of their container. Instead, it promotes the air pruning of roots and allows them to breathe. They are also vastly more environmentally friendly than their plastic counterparts. They are more expensive than regular plastic pots, but the pay-off with yields and plant quality is often well worth it. You can also buy fabric pots in a wide range of custom sizes with special features like air layers and handles.

    Terracotta pots

    Terracotta and clay pots are porous, allowing air and water to move through their walls. This means that your plant's under-soil is far more breathable than with a solid plastic container. Traditional and simple in design, they're tried and tested methods of promoting healthy cannabis growth. Many growers opt for these traditional pots because they naturally soak up and store excess moisture, which helps to cool the plant in summer and provide a slow release of nutrients. Standard terracotta flower pots with holes underneath for drainage also come with a matching saucer, which you can conveniently use to catch runoff water. Another side benefit of terracotta planters is their weight. They're heavy, solid and less prone to being knocked about. All of these qualities can help you achieve greater yields than a basic, plastic container.

    Air Pots

    Air pots offer similar benefits to fabric pots, promoting the circulation of air and oxygen from all directions under the soil. They are essentially smart plastic pots with numerous openings crafted into their sides. They need watering more often than plastic pots, as the water drains far easier. The main advantage here is that your roots can be automatically pruned by the air, promoting healthy growth, just like fabric pots. Unlike fabric pots, however, these are weighty and less prone to being spilled. Many models do not come with a saucer, so be sure to invest in one to catch the water as it drains.

    Grow some autoflowers yourself!

    There's no such thing as the single perfect pot. Choose the right container for your autoflower plant's size to make the most of your setup. To get started, simply opt for the best quality seeds out there from our autoflower selection. Look at the potential height when growing indoors or outdoors and choose your pot size accordingly. If you’re new to the growing scene, don’t let the number of pots and growing methods available deter you. Growing is fun, simple and easy for beginners to get started.