Today, I’m sharing 5 tips for growing autoflowering cannabis. These tips help get bigger yields and more THC. Here’s how I get massive top-shelf autoflowering harvests every time.
I always start with good quality autoflowering cannabis seeds. This ensures my seedlings grow strong and fast.
How things have changed. Now, autoflowering cannabis strains can match traditional strains in quality and yield.
Modern autoflowering strains have amazing bud quality. (Recommended strains at the bottom of the tutorial!)
Tactics for Growing Autoflowering Cannabis Strains
I’m on a mission to grow the best autoflowering cannabis yet. I’ve learned the secrets to growing a lot of potent buds. To get the most out of my plants, I keep 5 things in mind.
Start Strong (Most Important Thing)
Starting strong is key for big yields with autoflowering strains. These plants start flowering in just a month. A slow start means small plants with few bud sites.
Small plants can’t compete with big ones under the grow light. They have more bud sites.
Germination: I plant autoflowering seeds directly in coco or soil. This way, you don’t have to move seedlings after they sprout.
Plant your seeds and keep them warm during germination.
Light Schedule: My recommended light schedule for auto-flowering plants is 18 hours light/day. You can give autos up to 24 hours of light a day, but 18 hours saves 20% of the electricity and gets similar yields. Plus a 6-hour night increases the overall hardiness of plants vs giving them no dark period.
Watering Seedlings: The easiest way to stunt autoflowering seedlings is from poor watering. Give them the right amount of water (not too much, not too little) so they’re growing fast right out of the gate. Check out my guide to watering seedlings perfectly.
Give just a little water at a time in a small circle around the base of new seedlings. Water every few days.
Aim for 6 full sets of new leaves by day 25 from germination. If you accomplish this, you’re perfectly on track for this tutorial. If plants are smaller than that, it’s a sign you may have been able to improve your start, and plants may not be able to produce as much weed as they could have.
A “strong start” looks like this. These autoflowering plants are all 21 days from germination. Some are bigger than others, but overall they’re all growing fast and healthy.
Grow the Right Number of Plants for Your Space
For grow tents and indoor gardens, grow the right number of plants. Use the right size pots. I’ll share what works for the 3 most common grow tent sizes. Plus, some tips for growing outdoors or in a window.
Optimal number of autoflowering plants for your grow tent, with recommended pot sizes:
With autoflowering strains, grow a few more plants than you need. This is because some plants might not grow buds or could have problems. If you have extra plants, they can fill in any empty spots.
Mini Grow Tent (2×2′) – 2-4 plants
- 2 plants – Use 2-gallon fabric pots. Fabric pots help plants grow faster. With two plants, you can give them lots of care.
- 4 plants – Use 2-gallon fabric pots or 1-gallon hard-sided pots. Small fabric pots dry out fast and need water often. Hard-sided pots help plants stay moist longer, so you water less.
So I bent over the tallest stems and tied them down, until the plant was completely flat from the side.
From above, you’re creating a star shape by continually bending tall stems down and away from the center of the plant.
3 Highest-Yielding Auto-flowering Strains in 2024
- Glueberry Auto by MSNL – Up to 5 oz per plant in good conditions, THC up to 24%.
- Gorilla Glue Auto by Barney’s Farm – Big yields, up to 25% THC, 80 days to harvest.
- Ultimate Auto by Dutch Passion – Enormous yields, but low potency buds (they measured around 15% THC when I got the buds sent to the lab).
Glueberry Auto by MSNL is a huge yielder with high potency.
A few things to know about auto-flowering bud potency:
- THC percentage is mainly determined by your genetics. Grow practices make a difference, but can only move the dial by a few percentage points.
- THC continues to increase in most strains up until buds are completely mature.
- Most “fast” strains will result in better yields and higher THC if you give an additional week or two before harvesting.
- One thing auto-flowering breeders do to increase potency is to breed strains to produce as little CBD as possible, as low CBD makes it so the THC feels stronger. If you’re looking for a fast auto-flowering strain and care about buds making you feel “really high” then opt for a low-CBD high-THC auto-flowering strain.
Best Auto-Flowering Breeders in 2025
I’m going to share some tips on strains. But, it’s clear that the best thing for success is finding a good breeder. When a special strain comes out, it’s often from a top breeder.
Strains change, but good breeders stay the same. They offer many high-quality genetics. So, it’s better to find a breeder that has what you want.
These breeders are the best because they always bring new strains. They keep their genetics fresh and stay ahead in breeding.
No one is perfect, but these breeders have worked well for me.
5 Recommended Breeders Plus Some of Their Best Auto-flowering Strains
Barney’s Farm
- Grape Muerto Auto – Ready in under 70 days, beautiful grape smell to buds.
- LSD Auto – Psychedelic effects, ready in under 70 days.
- Pineapple Express Auto – One of the most famous auto-flowering strains of all time, this is ready to harvest in under 70 days from germination
- Purple Punch Auto by Barney’s Farm – This is one of the higher-yielding strains on this list, and is typically ready to harvest in under 60 days.
- Skywalker OG Auto – 23% THC, 70 days
- Tangerine Dream Auto – Ready in 70 days
- Wedding Cake Auto – As little as 62 days with the highest THC around 75 days from germination, very sparkly strain.
Ethos Genetics
On average, auto-flowering strains from Ethos Genetics are not as fast as the other breeders on this list, but they tend to be the most potent and look the most sparkly and like modern photoperiod cannabis strains.
- Banana Daddy Auto RBX2 – very potent but still relaxing effects (described as “euphoric) that may be a good choice for those with anxiety who still want to get high, with around 24% THC and 1-2% CBD. About 80 days from germination to harvest. Chunky buds and the plant stays a manageable height.
- Pineapple Runtz Auto by Ethos – Around 22% THC with an assortment of other cannabinoids. Starburst sweet smell. Gorgeous sparkly buds.
- Pluto Cut Auto R F3 by Ethos – Over 25% THC plus some of the more exotic cannabinoids give this strain’s effects some photoperiod-esque complexity you don’t often see in autoflowering strains. Feels very potent. Ready in 80 days.
Pluto Cut Auto R F3 by Ethos Genetics is one of the most potent autoflowering strains available in 2024. Easy to grow. Highly recommended.
Fastbuds
- Blackberry Auto – As little as 56 days from sprout, purple buds, great smell, excellent yields (especially for the timeline)
- Blue Dream’matic Auto – Ready in as little as 62 days though THC improves over another 1-2 weeks, dense buds, low CBD to help the buds feel more potent
- Cheese Original Auto – I haven’t had the opportunity to grow it yet, but I’ve heard some growers say this is the best Cheese in auto form.
- Cream Cookies Auto – Ready to harvest in about 60 days, beautiful sparkly buds, good yields
- Forbidden Runts Auto – Ready to harvest in 80 days, super sparkly buds
- Gorilla Cookies Auto – Ready in 70 days, great yields, low CBD to make it feel more potent
- Green Crack Auto – Just 56 days to harvest
- LSD-25 Auto – Gorgeous purple buds, potent effects, ready to harvest in under 65 days.
- Original AK Auto – For those who want those original AK effects in auto form.
- Six Shooter Auto – Easy to grow, good yields, 21% THC buds.
- Wedding Glue Auto – So many trichomes, ready in 60-70 days, good yields
- Ztrawberriez Auto – Ready to harvest in about 70 days, very high THC above 25%.
Mephisto Genetics
- Double Grape Auto – Purple tinted buds, ready in under 75 days
- Creme de la Chem Auto – A personal favorite, ready in 65-75 days (mine was ready in 70), loved the effects!
- Check out more Mephisto cannabis strains (all of their strains are autoflowering)
MSNL
Offers a ton of fast, potent autoflowering strains. These are all ready to harvest about 70 days from germination, and all boast THC percentages above 20%.
- Apple Fritters Auto by MSNL – Modern genetics in a fast auto-flowering strain. Up to 24% THC and ready to harvest about 70 days from germination.
- Bruce Banner Autoflower by MSNL – Over 25% THC, ready to harvest in about 70 days, big yields.
- Glueberry Auto by MSNL – A Gorilla Glue mix with up to 24% THC, and ready to harvest 60-70 days from seed
- Gorilla Cookies Auto by MSNL – Up to 24% THC, ready to harvest by 70 days from germination
- Purple Lemonade Autoflower – Up to 24% THC- ready to harvest in 70 days.
Fill your entire grow space under the grow light with autoflowering buds to get the best yields!
