by Nebula Haze
If you’re a home cannabis grower, and buds just aren’t as big as you want, there is a reason why. Some strains like Blue Dream just produce way more weed than others, but there’s a lot you do as a grower that affects bud size besides genetics.
If your marijuana buds are staying tiny, you can fix it by following today’s tutorial!
With the right grow tactics, and you can consistently produce big, dense, and long cannabis buds (known as “colas”).
Strain is White Rhino
Follow today’s tutorial to grow a literal sea of cannabis colas. That way you can enjoy enormous yields of top-shelf buds every harvest!
Strain: Ultimate Auto
Cannabis plants are straightforward in the way that if you grow the right strains and treat them right, they consistently make big buds for you.
This tutorial breaks down the exact reason why cannabis buds stay small instead of growing big, dense, and long colas.
Look over this list to diagnose why your buds aren’t getting as big as they could, and simply address the issues that are affecting your garden. Soon, you’ll be enjoying your own huge cannabis harvests with big yields. And as a bonus, the things that make marijuana buds grow big are also the things that make buds grow dense, potent, and beautiful. You’ve got this.
How Grow Environment Can Make Small Buds
Your grow environment has a remarkable effect on how buds grow. A lot of cannabis growers may focus on other aspects of growing, and unintentionally treat their growing environment as an afterthought. If you make sure to avoid the following pitfalls, you greatly increase your overall bud size.
Weak light levels (most common reason)
- Indoors: The grow light isn’t strong enough. Make sure to get the right-sized grow light for your grow space. Learn how to pick the perfect grow light for your cannabis garden.
- Outdoors: The plant isn’t getting direct sunlight, or not getting enough light hours per day (should be getting 8+ hours/day of direct sunlight)
This plant was grown under a tiny LED grow light. Weak light levels are the most common reason for small buds.
Grow light is too far away
This is actually just another cause of weak light levels, and it can affect your bud size even if you’re using one of the best cannabis grow lights. Keep your grow light as close as possible without stressing the tops of plants.
Learn how far away to keep your cannabis grow lights.
Cannabis buds tend to stay small if the grow light is kept too far away.
Note: If the grow light is the recommended distance away, but plants are still getting light burn or top leaves look stressed, it’s likely that they’re actually suffering from a nutrient deficiency or other sub-optimal conditions like too high temperature. When a cannabis plant is under stress of some kind, symptoms show up first on the hardest-working leaves. Cannabis plants can take more light than almost any other plant if you give them ideal conditions and great nutrition. So if the manufacturer says to keep the grow light 18″ (45 cm) away, for example, but your plants are looking burnt at that distance, look over the rest of this list to diagnose why.
If your grow light is the proper distance away but the top of plants look stressed, there is likely another issue going on (like too much heat or a nutrient deficiency).
Heat or Cold
Temperature matters! If a plant is too hot of cold, it just can’t make big buds. You may also notice the plant drooping or growing slowly when it’s hot or cold. The ideal temperature for cannabis plants is 70-85°F (20-30°C). The further you get outside that range, the more it will affect your bud size. Note: Plants under HPS or other HID grow lights prefer it on the colder side of that spectrum, while plants under LED grow lights prefer to be on the higher end.
Learn about the ideal temperature for growing cannabis plants.
This cannabis plant is suffering from heat stress.
This plant is suffering from cold (cold is also a common cause of red leaves or stems).
High Humidity (or Extremely Low Humidity)
Though not nearly as important as temperature for bud size, very humid or dry air can also prevent buds from getting as big as they could. Ideally, you’d like to keep your humidity around 40-50% while buds are forming (this also helps prevent bud rot). Giving buds lots of airflow via fans can help if the humidity is too high, but it’s best to lower the overall humidity if possible. Usually, cannabis plants are more tolerant of low humidity, especially if they’ve grown with it their whole life, but once the air gets under 30% humidity, your buds may not fatten properly.
Learn more about humidity effects on cannabis.
When growing marijuana, very high or very low humidity can inhibit bud size.
Re-vegging (reverting to vegetative stage)
This is a common nickname for when a cannabis plant is re-vegetating or returning back to the vegetative stage. You know your plant is re-vegging if buds start growing, but suddenly you see your plant growing round, single-finger, or twisted leaves, and soon after the buds stop developing and start to die. Re-vegging is caused when a flowering plant is getting light during its dark period. Even small amounts of light (like a light leak, or checking on your plants during lights-off) can set re-vegging in motion.
Learn about cannabis plants re-vegging (and see tons more pics, as every plant looks a bit different when it happens).
If a budding marijuana plant gets light at night, it may “re-veg” and cause buds to stop growing.
Learn more about how the environment affects cannabis buds.
How Certain Plant Structures Tend to Grow Smaller Buds
Plant is too small when it starts making buds
Small cannabis plants simply can’t support big buds. For a photoperiod plant, this happens when flowering gets initiated too early (given a 12/12 light schedule too soon).
When a photoperiod cannabis plant is put into the flowering stage too early, it just can’t make big buds.
Autoflowering plants start budding on their own, so if they’re too small it usually means that they didn’t get optimal conditions when they were young, and therefore didn’t get big enough before they started flowering.
Learn more: What causes auto-flowering plants to get stunted?
Example of a stunted auto-flowering plant.
Small roots
You don’t need huge roots to grow big buds, but if you’re growing in a cup or a 1/2 gallon pot, they’re typically not able to get big enough to support really big buds unless you do a lot of extra work to make up for what the roots would normally be doing.
Some growers like to push the limits with small roots, but it takes work to overcome. Learn about the “solo cup challenge”.
As a super general rule of thumb, a cannabis plant can grow about an ounce of weed for every gallon of root space. Of course, this is different for each strain and depends on the nutrients, grow medium, and grow practices. But that gives you a very general idea of what to expect for most growers in most conditions. For a few ounces per plant, 2-3 gallons is good. To get 5+ ounces per plant, you should have at least a 5-gallon container for the roots.
Small roots tend to limit your overall bud size. This cannabis plant grown in a cup was allowed to get tall but the buds stayed tiny.
Too many lower buds
Buds that aren’t located at the top of the plant will never get as fat as the top ones even if everything else is the same. That’s why it’s ideal to use bending and other pruning techniques to make your plants grow flat and wide. This means all the buds are top buds, which helps them bulk up to their maximum size and density.
Notice in the following picture how the top buds get the biggest even though the plant is getting the same amount of light from top to bottom.
Lower buds won’t fatten like top buds.
Get cannabis plants to grow flat and wide (via plant training) to make it so all buds are top buds.
Overly leafy plants (especially if buds are hidden by leaves)
If your cannabis plants are so bushy that the buds are all hidden from the grow light, they won’t fatten. Only buds that receive direct light get big.
Learn how to defoliate your plants so buds are all exposed to the light.
Buds won’t get big if they don’t get direct light. Notice how there are barely any buds on these plants where there are tons of leaves.
Buds hidden by leaves just don’t develop to their full potential. Buds need light!
Not enough leaves
On the flip side, if growers over-defoliate (remove too many leaves), and the plant is bare without many leaves, it can’t conduct enough photosynthesis to power the growth of buds. Another reason you might not have enough leaves is if your plant has lost a lot of leaves due to nutrient deficiencies, heat stress, bugs, or other challenges.
If your cannabis plant has almost no leaves left, buds tend to stay small, especially if combined with other issues.
Don’t harvest buds early!
If buds are small, sometimes they just need more time. If you harvest cannabis buds before they’re fully mature, it reduces their final size. In fact, in some cases, buds can double in size in just the last 2-3 weeks before harvest, which helps explain why early harvesting can have such a devastating effect on bud size.
If there are still white hairs sticking out, it’s too early to harvest your cannabis buds!
How Nutrient Issues Affect Bud Size
Not enough nutrients overall
If plants appear pale or lime green all over, this is a sign the plant needs higher levels of nutrients overall, even if you don’t see nutrient deficiencies.
If your plant is pale or lime green all over, it needs higher levels of nutrients overall.
Nutrient deficiencies
A cannabis plant that’s showing lots of symptoms on the leaves can’t conduct photosynthesis, which is what it needs to do to make energy to grow buds.
Learn how to stop nutrient problems.
When your leaves have lots of nutrient deficiencies, cannabis buds may grow, but would otherwise grow bigger.
Pests and Diseases Can Greatly Reduce Bud Size if Left Unchecked
Bugs and diseases can take away energy from buds, especially if they are left untreated. Luckily, as long as you identify and get rid of pests early, your plant should bounce right back.
Learn more about cannabis pests and diseases.
This cannabis plant is suffering from a severe fungus gnat infestation, and buds aren’t reaching maximum size.
Some Cannabis Strains Naturally Grow Small Buds (even if you do everything else right!) aka “Small Bud” Strains
Some strains just won’t make big buds even if you give a perfect environment, plant structure, nutrients, and keep plants healthy and happy.
For example, I once grew an “Ocean Fruit” strain, and all the buds stayed small even though the plant was healthy and all the other buds with the same conditions fattened up beautifully. When I talked to other growers who’d grown the same strain, they had a similar experience. That being said, the buds were amazing, so it’s not always a terrible thing.
This Ocean Fruit cannabis strain tends to grow small buds even in perfect conditions.
The bud quality was excellent though, so not a total loss! Size isn’t everything.
On the other hand, some cannabis strains like Chamba will get big even if you make lots of mistakes. However, if buds get too big, typically the overall bud quality suffers, and you’re more likely to run into issues with bud rot.
In my opinion, the best cannabis strains are high-yielding, but not absolutely nuts, like Purple Ghost Candy. Check out my full review of this strain.
I believe this is about the optimal size for cannabis buds that gives you a good mix of bud size and quality.
The Purple Ghost Candy above produced good-sized, super-dense, super-potent bud
Here are some of my favorite strains that give you high yields, but still make dense, nugget-like buds.
3 more recommended high-yielding cannabis strains
Kushberry Moonrocks by MSNL – Remarkably Strong
Example of Kushberry Moonrocks plants (by Victor)
Growing tips: Make sure to top these plants when they’re young and spread out all the branches as it grows. Other than that, it’s overall easy to grow. Just keep it healthy and give it lots of light for the best results.
Buds: This enchanting new strain has remarkable effects and looks/smells beautiful.
Aurora Indica by Nirvana – Stays Short!
Attention stealth growers! If you want a high-yielding plant that is quick to harvest, and actually stays short, than this may be the strain you’re looking for! For those of you growing in a smaller setup, a plant that naturally stays short and bushy can make growing much easier, and this strain will maximize your yields!
Growing tips: This strain seemed to do better with relatively low levels of nutrients compared to some other strains. We started at half nutrient strength when growing Aurora Indica for the first time (picture in upper right – yielded a little over 7 ounces), and actually had to take nutrient levels lower to almost 25% strength to get the best results in flowering. Aurora Indica plants are easy to grow and respond well to training and especially supercropping. Harvest at 7-9 weeks for a stoney “couchlock” effect.
Buds: Dense indica buds that are covered in trichomes, causing a heavy, almost sedating effect (“couchlock”). Our buds smelled earthy, with some fruity, almost minty tones underneath.
Zweet Inzanity by Ethos – Big Yields!
Zweet Inzanity impressed us with her high-yielding power and big, round, hard nugs.
Growing tips: This forgiving strain is extremely easy to grow, and responds well to FIMing/topping/LST and other training methods. It gets to a nice size – not too tall, not too short – and about doubles in size after the switch to 12/12. This strain takes about 2.5 months to finish flowering, and rewards you with great yields and chunky, round baseball buds. It tends to do best at relatively high levels of nutrients – we got great results feeding her at full strength.
Buds: Big yields. Dense, hard buds that sparkled, and highly potent yet friendly social vibes when smoking. Our buds smelled sweet and delicious.
