7 Environment Effects on Bud Quality

Published Mar 06, 2021

by Nebula Haze

What’s the secret to unbelievable bud quality? How can a cannabis grower produce delightful yields of dense, potent, beautiful buds?

Your growing medium and nutrients are important, but bud quality is more the result of two other things during your grow: Starting with the right strain and giving plants a great environment while buds are forming.

By the time you get to the flowering stage, the main bud quality factor under your control is the environment.

During the flowering stage…

  • Environment during the 2nd half of the flowering stage majorly affects bud potency, trichome production, appearance, and smell
  • Environment has a far greater effect on bud quality than the particular nutrient brand or supplements
  • Flowering environment is key to bringing out the best of your genetics (especially make sure to avoid too much heat!)

Want to harness the power of the environment in your own grow? Now is the time to start! Today I’ll teach you 7 ways the environment affects buds so you can produce the absolute best harvest possible. Master these 7 factors (usually just some small adjustment to “dial in” your personal setup) and you will be amazed at how much better buds turn out at harvest.

Learn how to “dial in” your flowering stage environment to produce superior buds

Quick Summary: Ideal Flowering Stage Environment

  • Temperature – 65-80°F (18-27°C)
  • Humidity – 40-50% RH
  • Grow Light – Bright light with far-red in the spectrum (high-UV is a bonus)
  • Airflow – Fresh air and a gentle breeze

Now that you understand what you’re aiming for in a general way, let’s dive deeper into how environmental factors affect bud quality so you know exactly what to focus on.

1.) How HEAT Affects Bud Quality

Too much heat hurts bud development and reduces quality. High temperatures cause the most damage when buds are close to harvest. Some strains are more heat resistant than others, but symptoms start for most strains above 80-85°F (27-30°C) in the flowering stage, and get worse the higher the heat and the longer the heat lasts.

Effects of too much heat…

Too much heat can severely hurt plants, especially if it goes on for days or weeks

Cannabis plants with crispy brown leaves after suffering from heat stress

Buds may be…

  • small, airy, and fluffy
  • discolored or burnt
  • harsh to smoke
  • poor or no taste/smell
  • low potency

Too much heat can dramatically lower the quality of buds

2.) How COLD Affects Bud Quality

It’s good to keep plants cooler in the flowering stage, especially during the last several weeks before harvest while buds gain the majority of their potency, smell, and size. A cooler environment (around 73°F/23°C) is ideal for bud potency and smell. Cool nights can help bring out colors like pink, purple, and red for some strains. However, plants grow slowly and buds stay small and airy if the environment is cold for the entire flowering stage so you need to wait until the end before letting the temperature drop.

  • Never let the temperature drop below 65°F/18°C to avoid stunting growth and bud development
  • Cold makes plants more susceptible to overwatering and nutrient deficiencies
  • Buds stay small and airy if it’s cold for the entire flowering stage

Cold plants grow slowly and may display odd symptoms like leaf curling, yellowing, and nutrient deficiencies

1st half of flowering stage – Aim for 78°F/26°C for fastest growth and biggest buds

  • Before buds have fully formed (when they still look like a bunch of white hairs), the temperature doesn’t have a huge effect on bud quality
  • Plants grow faster and buds get bigger when it’s warm, so don’t let plants get cold in the first half of the flowering stage
  • Focus on plant health and structure – don’t worry too much about avoiding heat just yet
  • Fast, healthy growth in the early flowering stage is key to developing lots of big/long bud sites

Keep plants warm during the first half of the flowering stage so plants grow fast and develop big, long bud sites

Don’t let the temperature drop too early as it can stunt bud growth and reduce your yields. These buds stayed small because the plant was cold for the entire flowering stage.

Cold temps can cause cannabis to produce whispy, larfy buds

2nd half of flowering stage – Aim for 73°F/23°F as buds approach harvest to protect bud quality

  • After buds have formed, a cool environment helps preserve bud smell and potency
  • Most important: Avoid letting it get hot!
  • Cold nights bring out colors like pink, purple, and red (if genetics allow), especially if temperature swings from day to night
  • If trying to bring out colors, make sure to wait to drop temperature until 1-2 weeks before harvest to avoid stunting

Keep the grow space cool (but not cold) after buds have formed

Cold temps can cause cannabis to produce whispy, larfy buds

Cold nights during the last 1-2 weeks before harvest can help bring out colors for some strains (both buds and leaves)

Bud quality (smell, taste, appearance, and potency) is best when plants are not allowed to get hot after buds have fully formed

Closeup – these plants received 70-75°F (20-23°C) for the 2nd half of the flowering stage

3.) How HIGH HUMIDITY Affects Bud Quality

Aim for 40-50% RH during the flowering stage for the best bud quality. A little higher is okay.

Above 60% RH…

High humidity can cause buds to grow small and loose

These buds are fluffy and airy - not dense at all. This tutorial will show you how to make your cannabis buds grow compact and dense every time!

High humidity increases the chance of buds rotting from the center, which requires you to throw away the entire bud. Noooooo.

Bud rot / gray mold can happen as a result of too-high humidity in the flowering stage

Mold growing on buds due to high humidity

No more mold or bud rot for your cannabis plants!

Powdery mildew also loves high humidity. It appears as random spots that look like flour or white powder.

Powdery mildew is often found on leaves but can spread to your buds if ignored

4.) How LOW HUMIDITY Affects Bud Quality

  • Great trichome production when humidity is 40-50%
  • Low humidity greatly reduces the chance of bud rot, even if buds are fat
  • You may see unhealthy, stressed growth if humidity gets under 35% RH
  • Buds may not fatten as well in low humidity, though some plants don’t mind (especially there’s been low humidity since the beginning of the grow)

Aim for 40-50% RH in the late flowering stage for healthy buds with great trichome production

5.) How TOO-CLOSE LIGHT Affects Bud Quality

Even if the temperature is under control, you can actually harm plants by giving them too much light. Typically this happens when indoor grow lights are kept too close.

Too-close grow lights produce problems:

Examples of light-bleached buds

Bleached white cannabis bud

Buds that have been discolored by light burn. Damaged buds look a little ragged and often have reduced smell and potency.

The sugar leaves on this bud were allowed to get yellow as the plant was deprived of nutrients too early in the flowering stage

Light stress can cause seedy buds even if herms don’t appear

6.) How TOO-FAR LIGHT Affects Bud Quality

  • Buds don’t get as big as they could have
  • When lights are way too far, they basically stop growing altogether
  • Otherwise, plants tend to be happy at relatively low light levels…

Keep lights the proper distance away to maximize bud quality and yields

LED grow lights need to be kept 18" away from the tops of your plants or more

Every grow light has an optimal distance from plants. This LEC grow light does best at 18-24″ away depending on the strain and bulb used.

Each model of LED grow light is different when it comes to the best light distance, so look at the manufacturer’s specifications or product details for guidance. This Electric Sky 300 produced excellent bud quality and size at 24″ away.

As long as the heat is under control, HPS grow lights can typically be kept closer than LEC or LEDs for the same wattage. This 250W HPS does best about 12″ away from the tops of plants.

Looking up at a 250W HPS grow light - the light given off is yellow or orange colored

7.) How LIGHT SPECTRUM Affects Bud Quality

  • UV (Ultraviolet): increase trichomes and smells
  • Blue: a spectrum that’s heavy in blue tends to keep buds smaller, may contribute to more trichomes, and may shorten the flowering stage
  • Green: necessary for plant health and fastest growth
  • Red: grow lights with a lot of red tend to produce bigger buds and may cause the flowering stage to last a bit longer
  • Far-Red: necessary for photoperiod buds to develop properly, seems to contribute to the best bud development

The best flowering grow lights have a bit of blue and green, lots of red and far-red, and bonus if it produces UV light (though watch your eyes!). The best flowering grow lights often appear white, yellow, or pink to the human eye.

Cannabis plants growing under a Quantum Board LED grow light (HLG300) by depthchargeseeds

One last thing about photoperiod strains…

Photoperiod strains need 12 hours of total darkness every day to produce buds. If there are light leaks (light gets to the plants during their dark period), photoperiod strains will….

  • Re-Vegetate – Revert back to vegetative stage
  • Herm – May trigger pollen sacs or bananas (causing seeds)

Check your grow space for light leaks (like these ones I saw along the seam of my grow tent when I got inside and shut the door)

Plants may revert back to the vegetative stage due to light leaks. When this happens your buds shrivel and die.

Don’t leave it to chance. Check inside grow space to ensure no light gets in from outside. Learn more about cannabis light schedules and light leaks.



I’m so proud of you! You made it to the end of the article. You now know exactly how to maintain bud quality in the flowering stage. Learn how to easily create the perfect plant growing environment.

And don’t forget these other important factors to exceptional bud quality:


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