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Indoor Humidity Control for Cannabis Plants

by Nebula Haze & Sirius Fourside

Table of Contents

Introduction

If you want to grow sticky, high-potency buds, your cannabis will demand attention to its many needs.

One need of the growing cannabis plant – that is commonly overlooked – is humidity.

Believe it or not, humidity is actually very important to your plant! Humidity will help determine your plants resilience against mold/mildew in addition to how much your plants need to drink. Getting it just right can improve plant growth and increase your yields.

Luckily, there isn’t much to learn, so you can be the master of humidity in your grow with very little effort! Today we will give you the information you need to have complete mastery over humidity and thus, give your plants a boost in production.

Why Humidity Matters To YOU

In all stages of cannabis growth your plants will have a constant need to intake water, and the amount of water they need fluctuates with the humidity in your grow room. When the humidity is high, cannabis plants use their leaves to absorb moisture from the air which causes them to drink less water from their roots. Conversely, when the humidity is low, they will pull more water in through their roots.

Since humidity changes how much water your plants drink, and the water you give your plants have nutrients in them, being in control of humidity gives you increased control over your plant’s nutrient intake.

But controlling humidity isn’t just about prevention…having the right humidity encourages strong, healthy, leafy plants with vigorous growth. In fact, growing with DWC (Deep Water Culture) / Bubbleponics during vegetation with the correct humidity can actually turn into a struggle to tame out-of-control plant growth!

Additionally, after your plants start making buds in the flowering stage and get close to harvest, you can manipulate the humidity of your grow area to get your plants to produce more resin (trichomes/glitter which contain THC and other cannabinoids) while preventing plants from being attacked by mold. High humidity can sometimes cause mold or bud rot – a grower’s worst nightmare for those fat, dense main colas.

Effects of Poor Humidity Management

We’re not out to scare you, but you should know what happens to a grow room with poor humidity management. We know how important humidity is because we’ve experienced every one of these problems firsthand!

White Powdery Mildew

White Powdery Mildew is a fungal disease that will shows up high humidity environments. This can be tricky since young cannabis plants flourish in humid environments. Luckily, you can stave off WPM by making sure there is proper airflow in your grow area; a small oscillating fan – even on the low setting – works wonders.

Bud Mold or Rot

Bud rot or mold is – in my opinion – one of the worst pains a grower can experience as a result of poor humidity management. Imagine harvesting a huge, dense main cola from your plant only to see the insides are totally white or brown with mold. Buds in this condition are unusable and 100% should be thrown away.

Nutrient Problems

Humidity is a factor that partly determines how much your plants will drink. If the air is dry, your plants will tend to drink more at their roots. If they’re already drinking more due to high temperatures, low humidity can cause them to drink a lot of water through their roots and uptake too-high levels of nutrients. If your plant takes in more nutrients than the plant can use, the leaves will begin to show yellow or burnt tips, which is the result of nutrient burn. Sometimes too-low humidity can cause other apparent nutrient problems.

Slowed Growth

Cannabis plants love higher humidity when they’re young, and lower humidity when they’re mature. To be frank, if they’re not getting these conditions, they may not be growing nearly as fast or healthy as they could.

Humidity Basics

Okay, so now you know why you need to manage humidity when growing cannabis, but you may not know what humidity you are aiming for. This chart is the quick-and-easy answer:

Humidity is actually a measure of how much water vapor is being “held” in the air. There are different ways to measure humidity, including “absolute,” “specific,” or “relative” humidity.

Most growers are talking about Relative Humidity or RH when they talk about humidity in the grow room.

Relative humidity measures how much water is in their air compared to the maximum amount of water that can be held in the air at that temperature.

Below is a quick reference for the major stages of the cannabis life cycle in regards to the relative humidity you are aiming for. We’ll go through them all in more detail

Clones

Optimal Humidity is 70% RH

Clones need time to develop a root system to intake water. Young clones are solely dependent on getting water through their leaves from the air and this is only possible with high humidity.

Maintaining high levels of humidity will dramatically increase the chances of clones rooting successfully, and will increase young clone growth.

This is why many growers use a humidity dome for new clones!

Young & Vegetative Plants (seedling to end of vegetative stage)

Optimal Humidity is 40-60% RH

Seedlings and young cannabis plants in the vegetative stage grow a lot of leaf mass in a great growing environment, and plants can sometimes grow foliage at a faster pace than the roots.

But the roots aren’t the only way your plant gets water. Leaves can actually pull water vapor directly out of the air, and higher humidity in the air allows the leaves to get more water to the plant if needed. Until your plant has fully developed roots, low levels of humidity in the air can cause growth to be slower.

The ideas is to create a comfortably warm environment that mimics springtime or summer.

  • Don’t give seedlings a humidity dome unless it’s very dry where you live. They need springtime conditions, but it can be easy to go overboard with seedlings (compared to clones which love high humidity).
  • The RH is too high if the plants are forming wet spots on their leaves even when they’re not touching each other
  • As seedlings get older and become young plants, they want the humidity around 50% RH
  • If the RH drops below 25%, the dry air tends to limit growth and cause nutrient problems to appear on leaves, especially for young seedlings. Some seedlings are fine, but other plants are particularly sensitive to humidity.

Humidity for flowering plants

Optimal Humidity is 40-50% RH

Ideally, the relative humidity of your grow room should be lowered to around 40-50% at the beginning of the flowering stage. As plants approach harvest, some growers lower humidity down below 40% or even less to force cannabis buds to produce more resin, though I’ve seen that can majorly stress some plants, so that technique should be used with caution. Definitely lower the humidity just a little at a time to see how plants react before putting your plants in an extreme environment.

By the beginning of the flowering stage, your cannabis plants have created a large root system to fulfill their water needs. They will still be able to take in water through their leaves, but maintaining a relatively lower humidity than the vegetative stage helps prevent molds or mildews from forming.

Mold is especially dangerous in the flowering stage because it can form on or inside your buds or colas without you knowing. If you find that you have mold growing in any of your buds, or buds are rotting from the inside, you should immediately throw all of the contaminated buds away. Bud rot can ruin entire harvests, so if one bud is infected thoroughly search your grow room for more. If you can’t lower the humidity and already have a rampant mold problem, the best choice might be to cut your losses and harvest immediately to avoid any other buds getting bud rot.

Even if the humidity is low, it is still important to have air moving over and around your plants. Small fans blowing over and under the plant canopy will help keep air moving so that wet spots don’t form around any parts of the plant.

Extra resin production

  • During the last 2-3 weeks before harvest, some growers will use a dehumidifier to drop the humidity of their grow area to between 40-45%. This not only prevents bud rot during the last few weeks, the lower humidity may stress the plant in just the right way to increase resin production. As a result, you harvest extra-potent buds with more sparkly trichomes. While this technique has not yet been proven to increase resin, many growers swear by it. Just be aware that lowering the humidity too much can cause stress to some plants (other strains react well).

Humidity for drying buds (early stage cure)

Optimal Humidity in the Drying Room is 55% RH (for beginners)

Keeping the humidity around the 50% range will allow your buds to dry, but keep them from drying too quickly.

This range is also optimal for preventing mold, so it doesn’t get any better for drying if you’re a beginner!

As an advanced drying and curing technique, some growers like to keep the humidity a little higher so buds dry slower (which could possibly increase the quality of your cured buds). Drying with high humidity is considered an advanced technique because drying must be done with extra care to prevent mold forming on your harvested buds!

It’s good to have air circulation in the drying area, but it’s recommended that no air is being blown directly over the buds to prevent them from drying too quickly. More information in the link below!

Learn how to dry and cure buds for professional results every time (no more guesswork!): https://www.growweedeasy.com/how-to-cure-buds

Temperature and How It Relates to Humidity

Temperature and relative humidity are closely related to each other.

Relative humidity is measuring how much water is “being held” in the air compared to the maximum amount of water that can be held at that temperature.

Warm air can “hold onto” more water than cool air. Plants will tend to thrive at different relative humidities depending on the temperature of the air. Once the air becomes too saturated with water, it will tend to form dew or films of water over leaves, which leads to mold.

For those interested in learning more about the science behind this, there is a term used by greenhouse growers known at VPD, or Vapour Pressure Deficit, that roughly measures the temperature and relative humidity.

According to Wikipedia: “the ideal range for VPD in a greenhouse is from 0.45 kPa to 1.25 kPa, ideally sitting at around 0.85 kPa. As a general rule, most plants grow well at VPDs of between 0.8 to 0.95 kPa.”

When growing plants, temperature is just as important as the Relative Humidity (RH) of the air, if not even more so! You need to control both temperature and RH at the same time to get the best results when growing cannabis.

  • If the air is too hot and dry (high VPD), plants will tend to have stretched growth.
  • If the air is too cool and humid (low VPD), plants are more prone to problems with mold or fungus.

Here’s what that means to you, the grower:

Cannabis likes a comfortable room temperature, or a little warmer – not too dry, not too humid. For most growers, that is all you need to worry about.

If your grow room feels warm or cold, humid or dry, that is a sign that you may want to look into changing the temperature and/or humidity of your grow area.

Generally, cannabis plants prefer temperatures in the 70-80 °F (21-27 °C) range during the day when lights are on. When lights are off (or at night), cannabis plants are happy with slightly cooler temps.

What if it gets too cold?

Colder temps will tend to slow down growth. Temps lower than 60°F (15°C) can upset plant growth and freezing temperatures will shock or even kill a cannabis plant.

Can cannabis stand higher temps? What if my grow room is too hot?

Please note that too-high temps in the flowering stage will not only slow down bud growth and cause fluffier buds, but it will also tend to reduce the potency of your buds by causing some terpenes and cannabinoids to burn off. Keeping the grow room temperature under control is important in the flowering stage!

  • With bright grow lights (such as 600W HPS and larger), cannabis plants can thrive at temps up to 85°F (30°C) even with no CO2 enrichment, as long as there is low relative humidity and plenty of air movement.
  • Cannabis plants can thrive at higher temperatures, up to an ultimate max of about 95°F (35°C), in an environment with low humidity, extremely bright grow lights and enriched CO2 (above 1500 PPM) – this is not your average grow!
  • Cannabis prefers slightly cooler temperature at night (warmer night temperatures will tend to slow down growth – so you can use this knowledge and raise night temperatures to slow down stretching plants that are growing too tall too quickly)

How to Control Humidity in the Grow Room

Step 1: Get a Humidity & Temperature Monitor to see if you need to adjust anything

I like the Ambient Weather WS-07 Wireless Thermo-Hygrometer because it lets you remotely check the temperature and humidity from another room (don’t forget to get 6 AAA batteries).

Step 2: Refer to Chart

Ideal temps are 70-80 °F (21-27 °C) during the day (lights on) and 5-10 degrees cooler at night (lights off).

Refer to the following chart to determine if relative humidity is in the ideal relative humidity range:

Young plants (seedling to end of vegetation)

40-60% RH (if you see wet spots forming on the leaves, humidity is too high or you need to increase air circulation). Beware of white powdery mold in humid grow spaces!

Flowering plants (making buds)

40-50% RH (a little less humidity helps protect plants from mold – during the last few weeks of flowering, a lower RH can possibly increase resin production as buds approach harvest)

Step 3: Correct humidity and/or temperature that is too high or too low

Many indoor growers tend to deal with too much heat and high temperatures – this is because grow lights can get very hot, and cannabis grows are often confined to very tight spaces due to stealth or privacy concerns.

The relative humidity of your grow area depends mostly on where you live, and how you’ve chosen to construct your grow area. Many growers struggle with lowering their humidity, because the mass of leaves and vegetation in a small grow area tends to cause the humidity to go up.

Here’s how you can correct common cannabis problems with heat and/or humidity.

Humidity:

Temperature:

Humidity is too high – how to lower humidity

Dehumidifier – will pull moisture from the air in a small area like a grow room or tent – a good one can be hooked directly to a drain for very humid areas like the UK and other humid parts of the world, otherwise dehumidifiers will automatically shut off when full and you will have to manually remove the water that it collects from the air.

Increase ventilation (add a more powerful exhaust fan or otherwise improve your exhaust system) – this increases the total amount of airflow in the grow area. This strategy will only work to lower humidity if the intake air has a lower RH than the air in the grow room.

Advanced: If you do get a high-powered exhaust fan to lower humidity, you may want to consider getting atmospheric controller with a humidity setting to automatically adjust the fan speed to achieve the humidity you want.

Avoid over-watering plants – soggy soil (or leaving extra water in plant trays sitting in the grow area) will tend to raise the humidity of the grow room

Consider slight defoliation – very leafy plants will tend to raise the humidity of the grow room, especially when there isn’t good ventilation or air flow.

Air Conditioner (some are portable, some ACs fit in your window) – tends to lower humidity (in addition to cooling the air)

Humidity is too low – how to increase humidity

Humidifier – will add additional moisture to the air, I like the evaporative type of humidifier because it also works to cool down temps slightly. Make sure you get a humidifier with a large holding tank (holds at least 6 gallons of water at a time). Those “one-room” humdifiers with a 1.5 gallon tank often need to be refilled several times a day.

This humidifier is an evaporative swamp cooler that holds 7 gallons of water at a time – great for hot, dry climates.

Swamp cooler – will cool down air while increasing the relative humidity; works best when humidity is too low and temperature is too high. Read how one user used a swamp cooler to control his humidity.

Temperature is too high (too hot) – how to lower temperature & cool things down

Increase ventilation (add a more powerful exhaust fan) – this increases the total amount of airflow in the grow area. This strategy will only work to lower temperature if the intake air has a lower temperature than the air in the grow room (if the air outside is hot, too, adding more ventilation won’t do much to lower the temperature)

Air Conditioner (some are portable, some ACs fit in your window) – in addition to cooling the air, an AC will also tend to lower the relative humidity of the air

Light Schedule – Consider having your lights turn on during the cooler parts of the day (for example some growers have their lights on at night, and keep lights off during the hottest parts of the day)

Temperature is too low (too cold) – how to raise temperature & heat things up

Insulation – Consider insulating your grow box or grow tent with something that holds in the heat

Bigger grow light – Get a bigger grow light to produce more heat within the grow space (and get plants to grow faster!)

Monitor temperature & humidity in your grow room!

I like the Ambient Weather WS-07 Wireless Thermo-Hygrometer because it lets you remotely check the temperature and humidity from another room (don’t forget to get 6 AAA batteries).

Monitor temperature & humidity even while you’re away!

Here’s a really simple solution that lets you check your temperature and humidity of your grow room in real-time, even if you’re not at home!

Buy an indoor/outdoor temperature+humidity sensor and display, such as the model listed above

Put the “outdoor” module in your grow tent or box.

Put the “indoor” display in front of a webcam (you may have one built into your laptop, or buy a cheap and easy-to-use one like the Logitech HD Webcam C310)

You could also put the “indoor” display near your desk for easy viewing, and then point a webcam at the display.

Install TeamViewer (it’s free for personal use) or you can also use Windows Remote Assistance (not as user friendly in the beginning, but a good choice).

You can now log into your computer from any other computer, open the program for the webcam, and see what your grow room stats are in real-time.

Thanks to Tokiehardo for this awesome tip!

Too Hot, Too Dry – Humidity Story from a Grower in Denver

I’m preparing things for my first grow and trying to make sure that I plan everything ‘right’ and I’m not surprised by too many things, and hopefully none too late to fix.

Humidity has me confused. I’ve seen sources saying the greater the humidity the better, some that say humidity makes no difference as long as the plant is hydrated, and some claiming nothing will grow if you’re not nailed at 45%.

The ambient humidity near Denver is pretty low – the room I plan to grow in sits at 20% on average. Is this too low for my plants to be happy?

This humidity is too low for healthy growth of cannabis plants. This grower decied to build something known as a swamp cooler:http://burningman.rengeekcentral.com/ swampcooler.html

It moistens the air while keeping the temperature down, which can also be a problem in Denver.

Update from the grower: For anyone stumbling onto this in the future, the swamp cooler in the link above is friggin awesome. I have it connected to my intake ducting and it’s keeping the cabinet at 73F with 80F outside temps! I cannot downplay how great it works, but I recommend creating a way bigger reservoir, so you don’t have to refill it every 6-8 hours.

Learn how to control humidity in the cannabis grow room to get faster growth and better yields!

The 7 most common errors drying cannabis

After months of giving our plants all the care they require, the time to harvest finally arrives. Whichever variety of cannabis you cultivate, you’ll probably want to dry it before consuming it. While to many it may seem the least important phase (the hardest part is over!), the correct drying of our plants is essential to enjoy the best possible quality, if we don’t take the necessary care with drying, we can ruin our efforts… and our entire harvest!

In our post about drying and curing cannabis, we gave you the basic information to dry your flowers perfectly. In this article we will focus on the most common mistakes made when drying our precious buds, mistakes that as we say can ruin the flowers we have been caring for months. Let’s see what the typical errors are when drying marijuana.

Hanging the buds to dry the is standard practice

Not checking the colour of the trichomes

Closely observing the colour of the trichomes is crucial to enable us to harvest the plants at the optimum time, with the maximum possible content of cannabinoids, terpenes, flavonoids, etc. During flowering, this colour changes from transparent to milky as the glandular heads of the trichomes fill with compounds, ending with a lovely amber colour.

Normally, the best time to harvest is with a large proportion of milky trichomes, and a small number are already showing amber tones. At this time the cannabinoid and terpene content is at its highest, so the flavour, aroma and effect of the buds will also be at their peak. This is the first step to achieve a quality product, which we will finish off during the drying process.

Harvesting with wet substrate

Once we see that we’re at the optimum point of harvest, it’s time to cut the plants. A common mistake, which can delay drying for several days, is harvesting the plants when the substrate is wet, or to put it another way, when the water content within the plants tissues is at the maximum. So if we want to properly dry our buds in the shortest time possible, it’s best to harvest the plants when the substrate has been dry for at least one day and their internal water content will be therefore lower.

In the same way, if we want to accelerate drying, it’s best to trim cannabis thoroughly before hanging them to dry, and also removing as much stalk and stem as we can. In this way less vegetable mass must be dried, and the bud drying process will be faster.

Keep an eye on the colour of the trichomes to harvest at the best moment

Handling the buds too much

Both when we’re cutting the plants or during the trimming process (and also when hanging them to dry), it’s very important not to handle the flowers excessively. Trichome heads – where the various compounds that give cannabis its flavour and high are produced and stored – are very delicate, and can easily break off if we touch the buds too much.

In fact, charas is made by manually rubbing fresh flowers to get a thick layer of resin (hash) attached to the hands. This is precisely what we want to avoid here if we want to keep our buds in perfect condition!

Not removing infected parts of the plant

Once we’re ready to trim, or to directly hang to dry if we want to trim the dried flowers, we must carefully check each bud looking for infection, in particular fungi such as botrytis or powdery mildew. If we hang a plant up to drywith some type of fungal infection, the infection may spread during drying, leaving uswith the unpleasant surprise of an infected and spoiled harvest.

It’s very important to remove any mouldy parts of the plant before drying

Incorrect humidity levels in the drying room

We already have our flowers cut, trimmed, and ready to dry. However, we must bear in mind that the relative humidity level inside the drying room will determine both the speed of the drying and the quality of it. We want a slow and uniform drying, without peaks in temperature or humidity inside the drying area, which should be kept as constant as possible.

The ideal humidity to dry cannabis is 50-60%. Any lower and the plants will probably dry too quickly, while if it’s higher, problems with fungi can arise and the drying process can also take forever.

Inadequate ventilation while drying

As we already mentioned, in addition to maintaining an adequate level of humidity, it’s important to avoid the air inside the drying room becoming stagnant. Many growers use their grow tent as a dryer, leaving the ventilation system on during the drying process. In this way, a correct air circulation is achieved inside, and if a carbon filter is installed, the intense smell of the plants is avoided.

You can also install a small fan to help the air circulate and avoid the formation of air pockets or moisture, although we recommend not to point it directly at the flowers we’re drying. This could cause them to dry too quickly in some areas of the plants, and as we know, what we want is slow and uniform drying.

It’s important to control the temperature and humidity in the drying room

Temperature and light in the drying room

As with humidity, an incorrect temperature can ruin our flowers, as can drying them in full daylight. Temperatures over 25 degrees can dry the plant too fast, the ideal temperature being about 18-20 degrees celsius. On the other hand, if we dry the plants in the light this will degrade part of the content of the trichomes, reducing the final quality of the buds.

The ideal is to dry the plants in a relatively cool, well ventilated and dark place. This way, we will avoid many of the factors that can cause drying to reduce the quality of our harvest.

We hope this article helps you to get finished buds of the highest quality. A last and useful advice: if your buds have got too dry, you can put them in a hermetic jar with a few fresh weed leaves (or some other vegetable). In this way, the buds will recover moisture, which they absorb as the leaves release it. When they are at the ideal point, we just need to remove the leaves and begin the curing process.

Feel free to leave us any doubts or observations you may have, we’re always happy to answer you!

Comments and questions about The 7 most common errors drying cannabis

I am drying in a grow tent i have 1 plant can I hang that upside down and put extractor fan at the top and circulation fan pointing down wiĺl that dry my plant ok . bearing in mind my room that tent is in is pretty cool ..around 15c i have no way of warming up my room that my tent is in …apart from central heating / radiator …could I have heating on really low like 20c or will it still dry around 15_18 c

Hello!
The important thing is to reduce humidity, provide ventilation and raise the temperature it is good to dry the plant. In these cases, a dehumidifier can be a great help.

i used to dry in my grow tent , i wasted 2 weeks waiting for it to finish.
than used dry net , but i had to put an industrial fan or else your weed filled with mold , and the smell was so strong . now i use wedryer and all my worries are over , and there is no smell . the day i trimme , i start a new cycle .
the electricity is minor and the product quality is the best i had until now.

With my house heater running, the humidity is low, can I dry in garage at 45f-55f degree because humidity is better? It’s dark , cool, and more easily able to move air.

hey thanks for this articale i have a question if im drying in 27-28 c and 40% humidity (i have no way to change that) how long shuld i dry them and what is the demage that im doing to them?

Well, while your conditions are not ideal, they’re not too bad. You should have your buds ready in about 2 weeks (just check the texture of the buds with your fingers until you feel like you’ll be able to grind them without problems). Still, you can improve the quality of the buds with proper curing, leaving them in sealed jars which should be opened just a few minutes once a day. You should have better buds after 3-4 weeks of curing.

I was reading that it’s ok to harvest some buds on your plant before others. They also say you can use your grow room as your drying area also. Mine is in a closet. My question is if I have some of the buds drying and the rest of the plant still in the flowering cycle will the light mess up the drying process? My closet isnt very big, like 8’×12′

That’s correct, although harvesting some buds before others is usually done when growing outdoors, where plants get really big and – normally – the tops are ready when the lower parts still need some extra days. Almost 100% of indoor growers harvest their whole plants on the same day.

As you say, trying to dry the buds with the lights on will definitely speed up the process, although quality will be lower. It’s always better to dry the buds in complete darkness.

Hope this helps!

That’s a solid article about growing cannabis, it’s important to understand the fundamentals of growing marijuana if you want to grow the super nice flowers, thank you for the hard work you put into gathering all of this great info. Have you heard of the new RSPEC Niemi Deep-Red grow lights are designed to enhance flower while still being a great full cycle grow light from seed to flower?

Thanks for your comment. Didn’t know about those lamps, will check them asap!

my dry room is a walk in closet temp is 72 degrees , what can I use to get temp to 20 degrees , just started 2 days ago… please help

Hi, your best bet would be a small, portable air conditioning unit/room chiller. If the walk in closet isn’t very large then you shouldn’t need a big, expensive model. Calculate the cubic footage of the space and find one that can comfortably cope with that capacity.

Also, presuming the temperature in the closet is 72º Fahrenheit, not Celsius (which would be insanely hot!), you only really need to reduce it to around 60ºF for a good drying temperature. Any lower than that and the air won’t be able to hold enough moisture to dry the plants. Getting the room temp down to 20 degrees as you suggest would be below freezing.

also I just put dehumidifier in today & set at 60 % & waiting to see if that will effect the temp 72 degrees , trying
to get room temp to 20 degrees or 30 , 40 , 50 anything closer to the correct room temp
Thank You

In my experience, de-humidifiers will actually work to increase the temperature of a room. The air-con unit will have some dehumidifying effect, although it may not be enough to dry your crop, in which case you’ll have to alternate between the two units to maintain the ideal conditions.

Hey great read thanks fir the tips. Say one has a 4x4x6 tent. Temps range from 24-26 daytime and 20-22 at night. Between 40-55 rh. Is it possible to dry some stems in the tent at night while the plants are still in flower then move them to a small closet during the day? In order to get airflow the closet must remain open. Will get a little indirect light but less than the tent during lights on time. Finally is it important to get fresh air into the room containing the tent and closet? Room has a dehumidifier and a wall mounted ac/heater with dehumidifying function. Tent has carbon filter and intake and exhaust fan but the room is a closed system. Exhaust fan vents into the room. Thanks in advance.

I don’t see the problem. If your closet was closed, then perhaps RH would raise too much during the night period. But if I understood correctly the closet is open, so there should be no problem. What concerns me is that you say plants will get some light during the night period? You should avoid that!

Apart from the light issue, your temp and RH ranges are optimal, so you should have no problems.

Thanks for such a informative article ! Good read and helps us newbies learn the are of cultivation. I live I’m melbourne Australia and my grow was outdoors . The weather has turned and I’ve harvested my plants even though I probably could of left them but with the rains starting to take more occurrence I didn’t however the dry room is my shed which has plenty of ventilation but has a skylight that’s shines light during the day and temps here in Melbourne are 15 degrees Celsius in the day and 9 degrees Celsius at night obviously depending on weather patterns but float at around 12 degrees Celsius at night . Humidity 71%

1. Do I need to put a temp tarp over my roof to make it completely black
And
2 . Is it too cold at night

I’m 3 days into drying. I hung most everything up on a line but hung some in a cardboard box. I found that in the box I maintained a good environment ie. 68-69 and 50-54% rh. So today I boxed the entire crop into another box. My rh shot up to 58%rh. Good air circulation and temperatures are within range. Second box is my concern being that it has gone up as high as it has. Dehumidifier and carbon filter is running to no avail. What to do? Thanks.

Is this ready to dry

I live in Thailand.Its 30 c most days.I don’t have access to a cool area? What are my options.
I love living in the tropics but this is a challenge.

Hey I’m new to growing, but old school stoner, got 4 girls in a 3×3 gorilla tent with 600 watt HPS, hortilux super bulb of course, and 2 6in intake fans with both carbon filters. I thought this would give me a good setup.. Everything is going amazing, im only using technaflora nutrients 8 different kinds, with royal gold basement mix for my medium, my question is about Flushing I heard so many different things that I can tell what’s best but I was told since I was using this kind of soil and the organic nutrients that I wouldn’t have to flush more than 7 days and another say two weeks and what happens if I go three weeks will that kill my plants or what cuz I’m trying to get the timing down perfectly cuz I would like to attend a flush or the best tasting flush I can do? What would you recommend also drying its 100 degrees where I live going to dry out in closets maybe bathroom with air conditioning vent but can keep it at 70 degrees during the day but overnight it gets up to 75 is that going to be okay or is that going to try it too fast I’m looking for a good 10-day dr14 and does it really make a difference if you drive trim or trim after you dry because I heard if you trim it all before you can dig rate the THC on the buds?

I just harvested my plant and drying my lady under my GAZEBO outside…she is hanging. The TEMPS are in the 50’s at night and in the 60’s – 70’s during the day….

Can I dry in a garage with lows at about 5 or 6 degrees Celsius

I was wondering how important is it to leave your plants in the Dark full time they are drying

Hey. Last year I pretty much wasted my first ever crop. I dried my bud in the basement washroom, with doors closed, lights off and a fan indirectly blowing against the wall circulating the air. Also had the exhaust fan from the washroom running non stop. The skunk dank smell disappeared after the first day of drying. Turned into an awful hay/grass/earthy smell. Curing didn’t bring back the skunk smell. They buds also turned brown and tasted like absolute $&it.

I feel like my problem was I couldn’t control the humidity in the room. It was naturally around 39%-40%. Room temperature about 20c. I’m not sure and I’d like to know if the humidity is the problem. All the homework and research I’ve been doing is saying it’s my humidity

Just plucked my 1st auto flower and this time I have –

In Basement washroom
Door closed
Lights off
Washroom exhaust fan going
Indirect fan blowing upwards
Humidifier set on low
Room temp 20.4c
Humidity 55%

The scary part is that it’s been drying a little over a day now, it still has the skunky smell, but I feel like it’s transforming into the hay/grass/earthy smell.

Wtf am I doing wrong?

Só i have mines drying in 31/34 celsius and humidity 49/64 whats the damadge that can happen?

Also im drying in my closet its a 3 door closet só o have fans Doing air circulation in One SIDE só theres always air movement

What souls i worried about and can the cure revert thoes damages??

Hey,
So for about 30 hours I used a fan to dry my plants, which were hanging. I had it on the lowest temp, but the plants were swinging a bit. I ended up reading that you shouldn’t do this, and quickly took the fan off them when I figured this out. I’m hoping I haven’t done too much damage. It’s in my basement, and they don’t seem to dry yet, but im scared I ruined my harvest… 🙁 ?

My plants have been drying for a week. Stems don’t snap yet. I am leaving on vaca tomorrow for 2 wks, what do I do? Will it hurt them if I leave hanging for 2 more weeks or should I clean and put in jars before I leave. Please HELP ASAP

Bruv your plants are going threw it’s own process if u bk noticed if you go in b4 ya go to bed it will be all dry to touch bud u go bk in. early mmorning the plant will damp again. It’s the just the process of the cambium still goingbthrew the cycle of bring that water up to your epi bud nd back down to r/s . If u gtbthem.hanging in a dark room sitting round 50 percent to 60 percent and as long it above 15 degrees c ull be sweet . Have your fan turned towards the wall so it’s still oscillating but nt directly onto plants . They shud not be waving around. … I’d recommend having ya cabin filter remain on low on 20 degrees . The darkness is key for taste nd aesthetics

Juatbfijished drying 48 in 3 .2 by 3.8 room that I built takes me 6 to 8 days to dry the lot with 4 or 5 days curing. Running strawbury kish and banana strawbury.

My bad cnt spell fornshit hope this makes more sense

Temperature: In the first 3 days the best temperature is around 20 degrees Celsius. This way the buds will dry quick, but not too fast. After 3 days the temperature should be lowered to about 17-18 degrees Celsius to slow down the process.

Humidity: In the first 3 days the relative humidity should be around 50%. After three days the relative humidity should rise to about 60%, again with the reason to slow down the drying process.

Air circulation: It’s very important there’s enough air circulation in the room, so it’s advisable to use an electric driven fan. A ventilation fan can also come in handy to control the temperature and humidity. Don’t point the fan directly on the buds though, this will dry the cannabis buds unevenly.

Darkness: The room should be relatively dark as light, especially direct sunlight, degrades THC

Just harvest drying in tent door open temperature 73 degrees humidity 63 is this good or do i how to drop both .

U curing after drying…
If so wrong matter much you can chuck fresh shade leaf on the jar with ya buds dont stuff them in. Just fi and have them lose not compact chuck a shade leaf .or if you have none abit of lettuce and that will hydrate it a bit . .
If not curigbi oeraonly wouldn’t worry bout 3 percent 60 percent is good humidity after day 3 4 . B4 the day 1 to 3 want to b round 55 percent as a average . Low 50s first 3 days after tht high fiftys.

Should be 20°c (68 °f) first 3 days and lowered to 17 18°c (64.4 to 66.2°. Im.a kiwi so I’m in °c ur in of chur hope this helped

Tht wht gets ur smell nd flavour and really thts were it at . We not 16 smoking hay weed no more. Do it for the love

@Terri if they been hanging longer than five days all gud snap a nug off break it in half nd put it on ur lip g. Ul be able to fell it if its dry or not if dry chuck in jars.

(DO NOT OVER FILL JUST NICE LOSE ND FLUFFY . FILLED … NOT PACKED CHUR )

each to there own . But have. Never failed me and always turns .out gud with abeutufull aroma . Chur

I’ve been growing 15 years and I quit hang drying a long time ago after realizing it just doesn’t work. What I do is fill grocery paper bags loosely with fresh cut and trimmed nugs. Roll the bag closed with a safety pin. Then put it in the produce drawer in the fridge then adjusting the humidity control of the drawer to 55% with a wireless hygrometer. The buds will up the humidity slowly so keep adjusting to 55%. In about a week and a half or two weeks, the humidity will drop to 45-50, then put it in jars and burp it 2 times daily for 10 minutes for 3 days, then burp 1 time daily for 3 days, then 1 time every other day for a week, then set and forget. Hope yall that have problems with hang drying and losing smell will come to their senses and try this method. Its what many cannabis cup winners do. I believe this secret is held onto deeply. You’re welcome

CAJ – You seem so have a problem understanding degrees Celsius and degrees Fahrenheit 🙂

You state your room is 72 degrees – if this is degrees F you are fine …. if it is degrees C then you are in an oven!

So, presuming (ahem), you are talking about degrees F … then taking it down to 20 degrees would make it well below freezing.

LOL. Don’t mix and match your units: that’s how they got into trouble with the Hubble Space Telescope … did the conversion wrong between millimetres and thousands of an inch 🙂

If i was to dry in a cardboard box with plant hung full with a small fan at the back of my tent while I still have plants flowering how would this affect the end product

He first time grower will my buds be ok hanging up in my cubord overnight without a fan my who house stinks of it Getting fan in morning so 12 hours will they be ok ?

Hey … awesome article here! Very good info! Anyways, how do I get my RH up?? And down for that matter? It’s driving me nuts. I have a AC-(old school) but she still works!! Have humidifier…. fans and cam never get the RH right amd have it stay….

The 7 most common errors drying cannabis After months of giving our plants all the care they require, the time to harvest finally arrives. Whichever variety of cannabis you cultivate, you’ll ]]>