How to Grow Cannabis Indoors: Step by Step Beginner’s Guide to Growing Cannabis
Growing cannabis can seem complicated, but it only seems that way because you haven’t been given the right information.
This cannabis growing guide will help you discover the best way to grow cannabis, for your unique situation.
Growing cannabis plants is actually pretty straightforward, and almost anyone with a few extra minutes a day and a minimal number of tools can grow their own professional-quality buds at home.
How long does it take to grow cannabis?
Indoor grows tend to be shorter than outdoor grows since you have more control over when the plant starts budding. Auto-flowering grows also tend to be very short.
On average, you can expect to enjoy the fruits of your labor in 3-4 months.
Let's dive right in!
Table of Contents
- Step 1: Choose Your Grow Area
- Step 2: Choose Your Grow Light
- Step 3: Choose Your Growing Medium
- Step 4: Get Cannabis Friendly Nutrients
- Step 5: Giving Your Plants Good Water
- Step 6: Regulating Root pH
- Step 7: Choose Your Strain and
- Step 8: Vegetative Stage
- Step 9: Flowering Stage
- Step 10: Harvest
Step 1: Choose Your Grow Area
Growing cannabis plants indoors is considerably more private than growing outdoors and you also get more control over your grow.
An indoor cannabis grow is surprisingly cheap to start and maintain, especially if you plan on growing just a few plants.
You have more control over everything in an indoor growing environment, which means that indoor growers can consistently produce high quality cannabis. However, indoor growing comes with more responsibility.
The plants are 100% reliant on your care and if you don’t provide everything your plants need, they will die.
What space works best?
You can grow cannabis almost anywhere that has easy access to water and fresh air…
- a spare room
- a closet
- grow tent
- extra bathroom
Temperature of the space is important and it's best to have some control over the temperature of the grow area. When growing indoors, the grow lights are an excellent source of heat.
Young growing cannabis plants grow fastest when the temperature is in the 70-85°F (20-30°C) range.
When plants get older and reach the budding/flowering stage, it’s best to keep temperatures slightly cooler, around 65-80°F (18-26°C)
If you’re growing just a few plants in a grow tent, you can install a fan to pull hot air away from the hot lights and out a window to keep things cool enough.
Some lights tend to cause more heat problems than others. Our LED grow lights are designed to provide ample light and a manageable amount of heat.
Step 2: Choose Your Grow Light
What kind of lights are suitable for growing cannabis?
There are lots of different grow lights for cannabis, but the number 1 choice among growers is always LEDs.
LEDs are much more powerful than CFLs or any other fluorescent lighting. They are the ideal grow lights when it comes to how much bud they can produce.
They’re also visually attractive in color and tend to be more appealing to growers who take pride in their setup.
LEDs are also the most technologically advanced with long life spans and lower electricity costs.
Step 3: Choose Your Growing Medium
Each growing medium that you can use has different care and watering requirements.
- Soil – grow in organic composted super soil for the easiest growing experience.
- Soil-less Mix – anything besides soil including coco coir, perlite, vermiculite, etc. (all soil-less mixes are technically considered hydroponic growing since there’s no soil).
- Directly in Water / Hydroponics – Get some of the fastest growth and biggest yields possible, especially when combined with HID/LEC/LED grow lights.
Many people recommend against growing cannabis directly in water for your first time, yet I’ve seen growers succeed at every grow type even on their very first grow.
What's the Best Option?
Starting with a mix of coco coir and perlite is an easy and effective method of growing cannabis. Growing with coco is an excellent choice if you're starting out because its cheap, holds water well, and doesn't the problems associated with soil (bugs, root problems, etc) making it great for indoor grows, yet its still hand-watered and very intuitive.
Step 4: Get Cannabis Friendly Nutrients
Soil growers – unless you’re growing with composted super soil, you will need to get cannabis nutrients made for soil to make sure your plants produce at their best. Even if you started with an amended soil like FFOF, you will still need to start adding nutrients once you reach the flowering/budding stage as cannabis plants are heavy feeders and your plants will have already used up most of the nutrients in the soil by the time budding begins.
Soil-less & Hydroponic growers – If you are growing in any medium besides soil, like a soil-less mix or directly in water, you will want to get cannabis nutrients specifically made for hydroponics. Some nutrients are even more specific; for example, Canna Coco is formulated to work best for growing weed in Coco Coir.
Looking for a suggestion? One of the simplest (yet inexpensive) nutrient systems that works extremely well for beginning cannabis growers is Dyna-Gro (Grow, Bloom)
Dyna-Gro can be used at half-strength in soil, water, coco coir, or any growing medium and works amazingly well for growing cannabis. It does not build up salt in your growing medium like many other inexpensive fertilizers, and it will never clog your hydroponic system.
Just use the “Grow” bottle during the Vegetative stage and the “Bloom” bottle during the Flowering stage. You can actually follow the instructions on the bottle. It’s super simple.
Like all nutrient systems, avoid starting at full strength or it can burn your plants! Learn more about nutrient burn. Only raise the dosage if you notice that your lower leaves are turning yellow and falling off (except in the last 2-4 weeks before harvest, when yellowing lower leaves is a natural part of the maturation process).
Step 5: Giving Your Plants Good Water
let’s talk about the “hardness” of your water…
The “hardness” of water describes how much extra “stuff” (like minerals and/or impurities) it contains. You can look online for your local water information (municipal), or you can test your water at home. Generally, 200-400 PPM (parts per millions) of impurities is acceptable.
If you are worried about the quality of your tap water, you can choose to use purified water, but you may then need to add extra Cal-Mag and possibly a few other supplements to help make up for the beneficial minerals and nutrients that are normally found in tap water.
Step 6: Regulating Root pH
It’s important to maintain the pH of your root environment to prevent nutrient deficiencies.
The easiest way to do that is to test the pH of your water before you water your plants or add water to your reservoir.
There are certain types of grows (such as when growing cannabis in organic composted super soil) where you don’t need to test your pH unless you run into problems. This is because with a properly composted super soil, you actually have a microbial colony living in the soil that will take care of the pH and hand-deliver the nutrients to the roots of your plants for you.
However, this is a rare exception to the pH testing rule, and almost all growers need to regularly test and maintain pH for a successful grow. If you’re not growing in super soil that you have amended and composted (or purchased) yourself, testing and maintaining pH is a MUST.
Even if plants do fine in the vegetative stage, cannabis plants tend to be more picky and prone to problems in the flowering/budding stage. Many growers have written in to tell me they got all the way to the flowering stage without testing pH, then were surprised that they start running into nutrient problems as soon as the plants start budding. In order to make sure this doesn’t happen to you, it’s important to get in the habit of testing pH right from the beginning!
Even if the right amounts of nutrients are present, your cannabis plants simply cannot absorb them if the pH isn’t in the correct range.
It’s actually really easy, quick, and cheap to learn how to check and adjust the pH of your water, and there are “pH test kits” specifically made for this purpose.
After you get the hang of it, checking and adjusting the pH and will take you less than 3 minutes each time you water your plants. And your results (monster yields with huge buds and healthy plants) will speak for themselves.
Soil: Maintain 6.0 – 7.0 pH
Hydroponics: Maintain 5.5 – 6.5 pH
Step 7: Choose Your Strain and Get Seeds
No one in the US has ever gone to jail or prison from simply ordering cannabis seeds online from overseas
If you are considering this for the first time, you may be surprised to learn that, because of the way the laws about customs work in America, it is actually reliable and safe to buy your cannabis seeds online from a reputable seed bank as long as you get it from outside the US.
Get Seeds – View a list of tested & trusted seed vendors
Get Clones – You need to know someone with live female cannabis plants if you want to get clones. Many cannabis dispensaries and collectives will sell clones to prospective growers, or you might know someone who can give you a clone.
Step 7.5: How to Germinate Cannabis Seeds
If you have a rooted clone, please go ahead to the next step.
One of the easiest ways to germinate a cannabis seed is to place it directly in a specialized starter cube like a Rapid Rooter.
Just keep the Rapid Rooters moist (but not soaking) and warm. It can help to put your tray on a seedling heat mat. Seedlings should pop in a few days to a week.
If you're using a rapid rooter, once the seedling has emerged, you can stick the cube directly into your growing medium or hydroponic system.
Step 8: Vegetative Stage
When is my plant in the vegetative state?
Once your plant grows the first set of leaves, its officially in the vegetative state.
Young cannabis plants grow fastest when their surrounding temperature is warmer than room temperature, around 70-85°F (20-30°C). But as long as it doesn’t get freezing cold or burning hot, cannabis plants are resilient and can continue to grow.
In this stage, your plant is focusing only on growing the leaves and stems.
If you're using nutrients start at half strength for young cannabis plants. Bring to 3/4 strength once the plant starts growing vigorously and if your plant displays signs of needing more nutrients even though the pH is in a good range.
Only feed nutrients at full strength if the plant is still showing signs that it needs more nutrients.
How do I know if my plant needs more nutrients?
Nitrogen deficiency is the most common type of nutrient deficiency. You can tell the plant needs more nitrogen when the lower leaves are turning lime green, then yellow, then falling off.
Step 9: Flowering Stage
This is the stage where your plants start making buds. This stage will last until harvest!
During this stage, you will need to…
- Change to a 12-12 Light Schedule
- Identify the Gender of Your Cannabis Plants
- Get Rid of Male Plants
Now we are at the exciting part!
Most strains of cannabis begin this stage once they’re getting at least 12 hours of uninterrupted darkness a night. Auto-flowering cannabis plants will start the flowering stage without needing a lighting change.
- You must change to a 12-12 light schedule, with 12 hours of light & 12 hours of uninterrupted darkness each day (usually accomplished by putting your lights on a timer)
The flowering stage is where your plant grows its gender revealing parts.
Unfortunately, for regular seeds, half your plants will end up female and half will end up male. That’s why a lot of growers prefer starting with clones or buying feminized seeds.
As cannabis growers, we’re only looking for females as female plants are the only ones that make buds. Male plants just make pollen sacs that cannot be used for smoking.
A week or two after you initiate the 12-12 light schedule, your plants will reveal their gender…
Female plants start growing wispy white hairs at the tops of branch joints. These are the pistils of her flowers/calyxes. You’ll get bunches of these calyxes growing on top of each other to make buds, and each calyx will have a few white hairs coming out of it. This is great news! It means this plant will eventually grow beautiful weed with buds/flowers/ganja that you can smoke.
Male plants start growing balls/pollen sacs with no white hairs/pistils. Unfortunately, most male plants do not develop psychoactive properties like girls do in their flowers. Plus, male plants can pollinate your female plants and cause them to make less bud and more seeds. Therefore, most serious cannabis growers choose to remove and dispose of male plants as soon as they show their sex.
Note: The sturdy green growths are not pistils, they are always there on both boy and girl plants. When looking for gender, you’re specifically looking for white wispy hairs (pistils)
Now that you’re fully in the flowering stage, it’s best to keep temperatures slightly cooler, around 65-80°F (18-26°C) to produce the most potent and beautiful buds.
It’s important to pay close attention to your cannabis plants during the flowering stage. This is because in this stage your plant is much more likely to suffer from nutrient problems as they’re focusing all their energy on growing buds.
Step 10: Harvest Your Weed
When are my Buds ready to harvest?
- Wait until your buds stop growing new, white hairs. By this point, your buds should be fragrant (the whole grow room or area will likely smell strongly of cannabis).
- Wait until at least 40% of the white hairs have changed color (darkened) and are curling in. This marks the beginning of the harvest window.
- Harvest when 50-70% of the hairs have darkened for highest THC levels.
The hardest part of growing cannabis for many new growers is waiting for the right time to harvest.
After you have cut off and trimmed all of your beautiful cannabis buds, hang them upside down in a cool, dark place with good air ventilation so that they can dry out.
Dry buds slowly for best results and check often for mold or overdrying. You’ve worked way too hard to lose your crop now!
After your cannabis buds have dried (thin stems snap, but the thicker stems are still a bit bendy), it’s time to start curing them so they’re smooth, taste good, smell good, and have the best effects.
To cure your buds, put them in tightly-closed quart-sized mason jars in a cool dark place. Fill each jar loosely about 3/4 of the way full.
For the first 2 weeks of curing, open the jars once a day for several seconds to get fresh air in your jars and release any moisture.
If your buds feel moist when you check on them, leave the tops of the jars off until the outsides of the buds feel dry to the touch. Too-moist bud is what causes mold!
Special products like used for humidity control will make curing a lot easier
After your cannabis has been curing for at least 2 weeks, start opening the lid once a week instead of once a day.
At this point, your job is done and you can begin to enjoy your cannabis! If you want to cure your buds longer, or if they are still too moist, its up to you!
This last step is your magic touch.