The flowering stage will always take about eight weeks—some strains take seven, some nine, some even more, it depends on the strain.
Unlike outdoor growing, you aren’t tied to the sun and the seasons. You will be providing the entire environment the plants need to grow, including the grow medium—soil, rockwool, etc.—and regulating the amount of water and nutrients they receive, as well as controlling temperature, humidity, and more for them.
A lot of people these days buy grow tents for their weed, but they aren’t necessary. You can grow in a closet, tent, cabinet, spare room, or a corner in an unfinished basement. Just keep in mind that you’ll need to tailor your equipment (and plants) to fit the space.
The first step in odor control is making sure temperature and humidity are under control in your grow space—high temperature and humidity will perpetuate odors.
The two factors you need to control to dial in the environment are temperature and humidity.
Indoor marijuana grow timeline.
Fans should be positioned to provide direct, even airflow throughout the garden. This typically involves using multiple fans that work together or fans that have oscillation capabilities.
You’ll likely yield about the same amount of weed in both cases, but more harvests mean you’ll have fresh weed to smoke more often and have more opportunities to grow different strains. But more harvests also means more work in cleaning up the space between harvests, trimming, etc.
Examine the tops and undersides of leaves for pests or discoloration—spider mites live on the underside of leaves—as well as stalks and branches. Also, check the soil for pests.
Fans are a must in a grow space to move air around, so buy some of those before an AC unit. If you find that fans aren’t bringing down the temperature enough, then you may want to invest in an AC.
Carbon filters usually work best when positioned at the highest point in your grow space, where the most heat accumulates.
But the benefits are great: LEDs last much longer, use far less electricity, create less heat, and the best designs generate a fuller spectrum of light, which can get bigger yields and better quality.
Proper air circulation will help maintain temperature and humidity, and also bring down odor. Ideally, air needs to move through a garden every few minutes, and you should create a vent to the outside. Oscillating fans, and intake and exhaust fans can move air through your garden quickly, taking odors out with them.
Inexpensive options include standard plastic pots or cloth bags, while some growers choose to spend more on “smart pots” or “air pots”—containers designed to enhance airflow to the plant’s root zone.
It’s also a good idea to have oscillating fans to provide a constant breeze in your grow room as it will strengthen your plants’ stems, making them stronger and healthier.
Check out our Guide on nutrients for more info.
Benefits of growing weed indoors.
These are just some examples of amendments commonly used in different types of soils. Heavily amended soils will have long lists that break down all organic nutrients they contain. Some companies create soils that offer a great structure with base nutrients, but allow you to fill in the gaps as you desire.
If your space is too humid, you may need to invest in a dehumidifier—also known as “dehueys.” However, keep in mind that while dehueys will reduce humidity, they typically increase temperature—you may need more fans or an AC when adding a dehumidifier.
Standard plastic containers are a popular option for growers operating on a budget. These pots are inexpensive and provide the essentials for your plants.
You’ll need a dedicated space for your marijuana plants—you won’t be able to move them around. Ideally, the space is next to a window so you can vent air from the grow space outside. Growing weed plants smell! Especially when flowering kicks in, you’ll want to redirect air so your house doesn’t reek of weed.
Fluorescent light fixtures, particularly those using high-output T5 bulbs, are quite popular with small-scale cannabis growers because:
You will definitely want to invest in a timer for your lights. Because the amount of light a plant receives dictates its vegetative or flowering stage, it’s important to give it a consistent amount of light every day, and that’s done with a timer. It’s a good idea to check your timer at least once a week to make sure it’s working properly.
Generally speaking, it takes anywhere from 10-32 weeks, or about 3-8 months, to smoke what you’ve grown. (It’ll be quicker if you start with a clone or an autoflower seed.)
Controlling temperature in your indoor grow room or cannabis garden can be achieved by manipulating these factors:
One trick to avoid hot temps is to have the grow lights on during the evening, when it’s cooler outside, and leave the lights off during the day when it’s hot. This may help bring down the temps, but you’ll only be able to work on the plants at nighttime when the lights are on.
Plants in the vegetative stage maintain a low odor as they haven’t begun to produce terpenes, the plant’s aromatic compounds. As weed plants transition into the flowering phase, trichomes will start to develop and produce terpenes, causing them to smell more.
The main drawback is fluorescent lights are less efficient, generating about 20-30% less light per watt of electricity used; space is another concern, as it would require approximately 19 four-foot long T5 bulbs to equal the output of a single 600 watt HPS bulb.
In addition to bulbs, HID lighting setups require a ballast and hood/reflector for each light. Some ballasts are designed for use with either MH or HPS lamps, while many newer designs will run both.
If you can’t afford both MH and HPS bulbs, start with HPS as they deliver more light per watt. Magnetic ballasts are cheaper than digital ballasts, but run hotter, are less efficient, and harder on your bulbs. Digital ballasts are generally a better option, but are more expensive. Beware of cheap digital ballasts, as they are often not well shielded and can create electromagnetic interference that will affect radio and WiFi signals.
Soil is the most traditional medium for growing marijuana indoors, as well as the most forgiving, making it a good choice for first-time growers. Any high-quality potting soil will work, as long as it doesn’t contain artificial extended release fertilizer—like Miracle Gro—which is unsuitable for growing good cannabis.
The biggest variability in how long a marijuana plant takes to grow will happen in the vegetative stage—after the seedling phase and before flower.
Date: September 15, 2021 Read time: 6 minutes.
Medical marijuana patients 18 years and older will be able to grow up to 3 mature and 3 immature plants at home starting October 1, 2021, with a cap of 12 total plants per household. All adults over age 21 will be able to grow under the same rules starting July 1, 2023. Plants must be grown indoors and must not be visible from the street. People who choose to grow their own plants must do so in their primary residence and where individuals under 21 can not access the plants.
Correct lighting is crucial, as it drives photosynthesis. In other words, your plants will not grow properly without proper lighting. Photo by: Gina Coleman/Weedmaps.
Nutrient Film Technique (NFT) is another recirculating system in which plants are suspended by net baskets or neoprene collars that run along a trough. A thin film of water and nutrients continually circulates through the bottom of the trough, providing food to the tips of the roots, while leaving a majority of the root mass exposed to air.
Aeroponics are hydroponic systems in which the roots are suspended in air and lightly misted with a nutrient solution on regularly timed intervals. This method can achieve faster growth rates while using less water and nutrients than other hydroponic systems, though this is considered of the most advanced methods of growing hydroponically.
AC systems maintain temperature and also dehumidify rooms. Fluctuations in humidity can affect plant health and should be controlled using a dehumidifier or humidifier, depending on conditions.
Cleanliness in an indoor garden cannot be overstated. Clean your entire grow room before your first grow cycle and after every harvest. The walls, floors, trays, irrigation lines, reservoirs, lights, and fans should be cleaned using a three to five percent (3%-5%) hydrogen peroxide solution, an efficient sterilizing agent that leaves no dangerous or toxic residues behind. Be careful what you bring into your grow room. Pets, dirty clothes, and contaminated clones can introduce unwanted pests and diseases.
Creating the ideal environment: lighting.
Other common soilless mediums used by hydroponic growers include perlite, vermiculite, coarse sand, and gravel. Advanced growers frequently mix these media in custom quantities to create blends that suit their specific growing style and environment.
Hydroponics is a blanket term for the growing of plants in a nutrient solution, with or without an inert medium to provide physical root support. Media such as fused basalt rock and chalk (known as rockwool), coconut fiber (coco coir), and clay pellets (hydroton) can drastically improve nutrient delivery. With a plant’s roots system exposed, hydroponically grown cannabis can grow faster and more efficiently, requiring less water and fewer nutrients but also requiring monitoring systems to ensure a stable pH.
The amount of CO2 you supplement your garden with depends on how much light your plants are receiving, the growth phase they are in, and their overall size. CO2 should only be used during the “daylight” period, as plants are unable to utilize CO2 at night or in the dark. Sealed grow rooms are ideal when supplementing CO2, as open rooms tend to exhaust the CO2 more quickly than the plants can use it.
When using soil as your primary medium, drain-to-waste is the only possibility. In soilless hydroponic systems, it is up to the growers’ preferences. Most hydroponic growers will opt to maintain a drain-to-waste system, because it affords them full control over the application of nutrients. Recirculating systems are typically reserved for the most advanced and efficient cultivators.
Air conditioning (AC) and humidification systems are used to control the temperature and relative humidity of an indoor grow room. The size of each unit is based on the amount of heat the lights and other equipment produce in relation to the size of the space. In an open grow room, intake and exhaust fans are used to constantly exchange the air within the room to maintain a consistent temperature. In sealed rooms, mini-split AC systems are used because they circulate the air in the room without bringing in fresh air.
Controlling the amount of available carbon dioxide (CO2) in your garden is another aspect of growing marijuana at home . During photosynthesis, CO2 converts into sugar, which the plant uses as energy for growing its vegetation and, ultimately, its seeds or flowers. Adding CO2 to your indoor garden can drastically improve your yields. While the atmosphere naturally has an average CO2 concentration of around 400 parts per million (PPM), most indoor growers try to maintain a range of 800 to 2,000 PPM, depending on the plants’ growth stage. Levels above 2,000 PPM can damage plants, and anything above 3,000 PPM can be dangerous to humans.
Maintaining a grow journal and logging all major aspects of your grow is one of the cheapest, easiest things you can do to become a better grower. Logging daily temperatures along with water and feeding amounts will help you pinpoint problems, and may give you something to show other growers who can help you resolve issues, increase your yields, and save a troubled crop.
Choosing the right horticultural lighting for your indoor grow can mean the difference between success and failure. Correct lighting is crucial, as it drives photosynthesis. In other words, your plants will not grow properly without proper lighting. The duration of your lighting controls the photoperiod, or the times in which a grow is exposed to light. During the vegetative growth phase, plants need a minimum of 16 hours of light. The most common schedule during this phase is 18 hours of light and six hours of darkness. To initiate flowering, plants need a shorter day, with 12 hours of light and 12 hours of darkness.
Indoor cannabis cultivation is a rewarding endeavor that basically can be done in any climate. Growing pot takes attention to detail and the right equipment, time, and money, but the benefits reaped from growing your own weed are more than worth the time and expense. Not only is the practice of gardening itself therapeutic, it also lends a connection to the plants that cannot be experienced outside of a hands-on approach. Having trained and grown out a favorite cultivar to fruition is one of life’s great joys for a marijuana enthusiast.
Setting up your grow: choosing a space.
Hydroponic media are viable indoor alternatives to soil, but they’re considered more advanced because they bring with them a set of challenges that may prove difficult for beginners. Then again, if going hydroponic is in your plans, it’s best to learn the method from the beginning.
Even when growing cannabis legally, it’s a good idea to minimize your public visibility as a grower and take some mild to moderate precautions. Simple steps, such as not geotagging your location when you post grow pictures or hiding the glare from your grow lights when you run them at night, can go a long way in keeping your prized indoor garden secure.
With lighting, AC, and other environmental controls in place, indoor cannabis plants will require large amounts of fertilizer or nutrients throughout their lifespans. Hydroponic systems lack the base nutrients that occur within soil; that leaves it up to you, the grower, to feed their plants with nutrient concentrations — the exact formula of which depends upon plant variety and phase of cultivation. With hydroponics, salt-based nutrients typically come in the form of a concentrated liquid or dry soluble powder that can be mixed with water.
Whether you are growing two or 30 plants in your house, grow equipment requires a significant amount of electricity, primarily from your lighting and air conditioning units. Make sure that all electrical equipment is installed by a trained professional to reduce the likelihood of an electrical fire. You don’t need to be an electrician to design an indoor grow, but having a basic understanding of watts, volts, and amps is essential. The equation below can be used to determine whether your property has the minimum amount of power for an indoor garden:
The health of your garden is completely dependent upon the environment you create and the equipment you select. It is easy to buy a new line of nutrients, but much more difficult to replace an undersized air conditioner. Careful planning prior to your grow will go a long way in saving you from expensive mishaps.
There are several different types of grow lights that serve different purposes, each with their own sets of pros and cons.
Most local jurisdictions require you mitigate the odor from your plants to avoid disturbing your neighbors. Activated charcoal filters absorb plant odor in your grow area. Adding a charcoal filter to your HVAC system or placing one within your grow space is a great way to drastically reduce the odor. The size of the filter is largely dependent on the size of your grow. Make sure filters are sized and installed correctly. Keep track of the life of the filter, as their effectiveness diminishes over time.
Metal-halide (MH) lights are a type of high-intensity discharge (HID) lights that work by igniting gas in a tube with a spark of electricity. Metal-halide bulbs emit a spectrum of light that is most beneficial during the vegetative phase. They emit more usable light for a plant than a fluorescent bulb does, but tend to cost substantially more.
Remember, not everyone was born with a green thumb or an affinity for setting up and maintaining equipment. But with practice, passion, and an attention to detail, you can ready yourself for an amazing growing experience that has the potential to change your views of and interaction with cannabis for good.
Hydroton is a lightweight expanded clay aggregate composed of porous clay pebbles that can be used alone in a hydroponic system or blended with soil or other soilless mediums. Hydroton does not retain water to the extent of coco coir or rockwool, but it does provide plant roots with equal levels of oxygen. Like rockwool, the biggest issue is that it can dry out very quickly, so you have to be extra careful to keep it hydrated, especially when used on its own.
To set up an indoor garden, you will need equipment to help create a stable environment that mimics the necessary periods of light and darkness to grow plants through the flowering stage. This includes horticultural lighting, fans to recreate a gentle breeze, dehumidifiers to maintain the proper humidity, HVAC (heating, ventilation, and air conditioning), and all the basic supplies that a plant needs to survive, from water to grow media to nutrients.
Advanced growers use digital environmental controls to monitor all equipment responsible for maintaining a stable environment (i.e., fans, AC, dehumidifiers, sensors, thermostats, etc.). These environmental controls can be worth the hefty price tag for the peace of mind they provide.
High-pressure sodium (HPS) bulbs are highly efficient HID lights that produce a very effective spectrum of light to promote growth during the flowering phase. Most HPS bulbs are double-ended and can last 10,000 hours without losing efficiency. While these lights are the workhorses of most grow rooms today, they produce a significant amount of heat that needs to be removed, increasing air conditioning requirements.