How to Fatten Up Buds Before Harvest?


Thicker, more compact, and heavier buds are what we’re looking for. Usually, you can see the most bud development during weeks 5-7 and it can be disappointing to see the light, airy buds; they are not what we imagine when we first start growing.

If you’re feeling down about your light buds and are wondering how to fatten up your buds before harvest, we will help you out—we will list some variables that can influence your yields\How to fatten up buds before harvest. Of course, different strains of cannabis have different densities but there are some good ways to develop fat buds.

How to Fatten Up Buds Before Harvest

Be patient -How to Fatten Up Buds Before Harvest

Why do I list patience first? Well, the last few days before harvest are extremely important. We usually get excited and can’t wait to harvest, however, you need to wait! At the end of a grow your plants are probably doing very well and waiting just a few days will not hurt them—if you’re impatient you may be harvesting before your plants even fully develop! What a shame that would be—be patient, just wait a little longer!

Harvest when your plants are ready to harvest. Observe the trichomes with a magnifier—most growers harvest when the trichomes are milky white.

The color of trichomes is divided into three stages

  • Transparent: THC is low at this time; they are not ready for harvest
  • Milky color: THC reaches its highest potency and flavor; THC level is higher than CBD level during this stage
  • Amber: THC is converting into CBD; thus, the CBD level is higher

the Color of Trichomes in Three Stages


Factors that affect the buds before harvest -How to Fatten Up Buds Before Harvest

Light intensity

Light is the most important factor that helps your plants to grow dense buds. They need light to perform photosynthesis—light can be transformed into the sugar they need through photosynthesis; they feed on light.

To some degree, more light translates to fatter buds and higher yields (you’ll need to pay attention to the distance between your grow light and plants or your plant may suffer from light burn). Increasing light intensity is the most effective way to fatten up buds.

The right nutrients

Nutrients also affect bud size. Proper nutrients can help plants to grow denser buds. Plants can’t live without light, but they can develop buds without nutrients and those buds will likely be airy and light if you don’t have the right nutrient mixture. Cannabis needs a lot of P (phosphorus) and K (potassium) during the flowering stage. P encourages bud development and K helps the plants become more resilient.

We can start with a small dose to avoid nutrient burn and nutrient lockout (both of these will decrease your yields and even destroy them!). If you are facing any nutrient problems, you can check our previous articles where we discuss how to fix burn and lockout. If your leaves are green and healthy without any burnt spots, discoloration, or curling, you’ve done a great job with nutrients and there is nothing to worry about.

Temperature and humidity

Temperature and humidity are always crucial factors in the cycles of cannabis. Keep the temperature around 75℉ during the day, and about 10℉ lower at night. Keep humidity between 30%-40%; moisture will cause a lot of problems in buds such as fungus and bud rot and providing the ideal temperature and humidity levels increase the fragrance of your buds in the best way!


CO2 contributes to photosynthesis. When you have increased the light intensity you can (and sometimes need!) provide more CO2 for photosynthesis. Cannabis in an enclosed environment will consume CO2 quickly so if you don’t add CO2 at consistent intervals low CO2 levels will slow the growth. There are a number of ways to increase CO2—we’ve broken them down in another article; excess CO2 can be a great way to grow some enormous buds.

The other ways to fatten up buds along the way

1. Train your plants-How to Fatten Up Buds Before Harvest

Planting training is a common way to improve the quality and yield of cannabis. The maturation of cannabis plants depends on a plant hormone called auxin. Auxin is concentrated at the top of the plant and encourages the plant to concentrate its growth upward through the main stem. Training methods are used to reduce concentrated upward development and encourage growth in level coverage.

There are two main methods to train cannabis plants: low-stress training (LST) and high-stress training (HST)—we will discuss the topic in the next article so if you are interested in learning more about training your plants you can subscribe to our newsletter for the updated article.

2. Lower humidity in the last 24 hours before harvest-How to Fatten Up Buds

Lower humidity can increase resin quantities.

3. Stop watering 1-3 days before harvest-How to Fatten Up Buds

When you stop watering your plants will get stressed and they will think they are dying and will put all of their effort into reproducing. This phenomenon is similar to wine grapes: growing wine grapes in dry weather will encourage the plants to produce smaller grapes that are much more flavorful. This technique is useful for a lot of fruiting plants.

4. Flush before harvest-How to Fatten Up Buds

Flushing before harvest can improve the quality of cannabis—when the nutrients in the soil are flushed out the plants will use up the nutrients stored in their system, but if you flush too early, it will reduce your yields! Be sure to do research on your specific strain for the best results

5. Cut down old fan leaves-How to Fatten Up Buds

Once the old, fan-shaped leaves are removed the buds will be exposed to direct light and the plants will put more energy into growing buds.

All in all, as long as you provide an ideal environment for your plants you won’t be disappointed in their buds. In addition to these, you can try other techniques such as plant training and flushing before harvest, to further fatten up your buds.

If you are an experienced grower and have other tricks to help begin growers grow fatter buds, comment and tell us! New growers are always looking for more advice and we really appreciate all the support and feedback the community shares.

Happy growing!

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