3 or 5 Gallon Pots For Autoflowers? (Answered)

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If you are planning on growing some autoflowering weed plants, then you are set to have some great weed in just a few months’ time. That said, you do need to have the right pot size for the plant but is there really a difference between a 3 or 5 gallon pot for autoflowers?

3 gallon pots are a better choice for autoflowers, 3 gallons is large enough for most autoflower strains and there doesn’t seem to be much of a size or yield difference when comparing 3 to 5 gallons to justify the extra cost and soil use.

The only situation where we would recommend a 5 gallon pot is if you were growing a specific autoflower strains that grow bigger than the other autoflowers, but this isn’t very common. Bottom line is  stick with a 3 gallon and you will be just fine in most cases.

3 or 5 Gallon Pots for Autoflower


Are 3 Gallon Pots Big Enough for Autoflowers?

Generally speaking, yes 3 gallon pots should be large enough for most strains of autoflower weed plant. Now, some strains do grow a bit bigger than others, and for these you may want to consider a 5 gallon pot.

Also, keep in mind that a larger pot does usually lead to a slightly larger plant. Therefore, if you don’t have enough room to spare, you may use a 3 gallon pot no problem. A 3 gallon pot has more than enough space for most autoflowering weed strains.

Another rule of thumb with weed plants to keep in mind is that your plants should have roughly 1 gallon of pot space for every month that they will be alive.

Seeing as autoflower weed plants take around 3 months to go from seed to harvest, a 3 gallon pot should therefore do just fine.

Is it Worth Using 5 Gallons Pots for Autoflowers?

In terms of the size and yield difference of your autoflower plant, having a larger pot is really not going to make much of a difference.

So, sure, you could use a 5 gallon pot instead of a 3 gallon pot, and you might get a couple extra grams out of it, but that’s about it.

For the most part, the difference is going to be negligible and spending extra money on larger pots and more soil most likely is not going to be worth it.

You’re actually better off buying more autoflowering plants to grow in smaller pots in that same space. Instead of growing 3 plants in 5 gallon pots, you could grow 4 plants in 3 gallon pots in that same space, which is something that will help increase your overall yield.

two 5 gallon pots

3 Gallon vs 5 Gallon Yield

When it comes down to it, using a larger pot for an autoflowering plant is not really going to make a difference.

The reason for this is because the main factor that will determine the yield quantity with autoflowering plants is how long they are in the vegetative state for.

Well, autoflowering plants are specifically engineered to only spend 6 weeks in the vegetative state, no more and no less, and this runs like clockwork.

From all anecdotal evidence that can be found online, there is no real difference in yield when growing an autoflower plant in a 3 gallon pot when compared to a 5 gallon pot.

Do Autoflowers Take Longer in 5 Gallon Pots?

The really neat thing about autoflower plants is that they don’t take longer in 5 gallon pots than in 3 gallon pots.

In fact, they always take the same amount of time to go through both the vegetative and the flowering stages, which is 6 weeks per stage, or 12 weeks or 3 months in total.

Autoflowering plants will switch from the veg to the flowering stage automatically after roughly 6 weeks, and this happens all on its own, without any outside input.

Transplanting from 3 Gallon to 5 Gallon: Guide

Even though it’s not going to make a real difference, if you do want to transplant your autoflowering weed plant from a 3 gallon to a 5 gallon pot, follow the simple steps as listed below.

  1. Do not water your weed plant on the day you want to transplant it. The soil should be moist, but not wet, but also not dry. If the soil is too moist, the heavy soil may rip off or damage roots, but if it is too dry, then all of the soil around the roots is going to fall off.
  2. Now, take your pot and give the sides of it a good squeeze around the perimeter, as this will help loosen the plant.
  3. Get your new 5 gallon pot and put some soil in it. Make sure that the soil reaches a level in the pot that will allow the weed plant, the bottom of the stem where it grows out of the ground, to be just under the rim of the pot. Also make sure that the pot in question has good drainage so you don’t drown the roots of the plant.
  4. You now want to firmly yet gently hold your weed plant by the stem and pull it out of the pot. If you are having trouble doing so, you can gently turn the pot on its side, or even upside down, while supporting the stem.
  5. Take the weed plant and place it in your new pot, fill it in with soil, pack the soil down, repeat this process, and then give the weed plant a good watering.

Verdict: 3 Gallon or 5 Gallon Pots for Autoflowers

As you can see, using a 5 gallon pot for autoflowering weed plants, while it may make them grow slightly larger, really isn’t going to make much of a difference in the grand scheme of things, so a 3 gallon pot will do just fine.


My passion for the sticky icky started nearly a decade ago, and it all began when I first laid my eyes on the beauty that is the marijuana plant.

I cover all aspects of growing from equipment recommendations to plant health/care tips to help both new and experienced growers.