A Quick and Easy Guide to Getting Started with Growing Cannabis Indoors

Cultivating cannabis indoors requires understanding the basics of plant growth, lighting technology and climate control.
Soilless mixes are more forgiving than hydroponic systems/ Justin Cannabis

Planting Seeds

We all want to see big frosty buds but, as with everything else in the plant world, you have to start at the beginning—by germinating the seeds. Although they should pop open within a couple of days, be patient—it can take up to 7 days for a seedling to emerge from the surface of your growing medium.

Things to Consider: Seedlings require warm and wet conditions to thrive. If you think of typical spring weather, this will give you a great idea of how warm and moist the environment should be.

The taproot of your seedling will grow deep down into your growing medium, searching for moisture and nutrients as it expands its root hairs to every corner of the grow pot. Avoid overwatering the seedlings and always encourage the roots to grow as deeply as possible by creating a wet-to-dry cycle, only watering when necessary.

Foliar feeding, or misting your seedlings using a spray bottle, will help keep the environment humid while also allowing the leaves to utilize any mild nutrients in the spray. Be sure to spray with a light mist, taking care to spray the undersides of the leaves as well to keep them clean.

Use feminized seeds to ensure that all your seeds produce only female plants. The advantage in using these seeds is that there’s no need to determine the sex of the plants and remove the males from the garden, allowing the grower to maximize space at all times.

When using regular seeds, the grower will be required to look for pre-flowers to identify male and female plants. Some growers prefer to use regular seeds to grow out a mother plant from which to take clones, so both regular and feminized seeds have their advantages.

The Vegetative Stage

When plants are kept under a lighting regime timed to replicate the spring and summer months, they remain in their vegetative stage, growing only leaves and branches but no flowers. During this stage, most growers set their light timers for an 18/6-hour day/night light cycle (18 hours on and 6 hours off). The plants will only begin blooming later, after the light cycle is changed to 12/12-hour day/night. Unless you are working against a deadline, it’s a good idea to keep your plants in the vegetative stage for 4 to 6 weeks.

Things to Consider: It’s very important to make sure that your vegging room’s temperatures and humidity are on point. You want to achieve an average temperature of 68-75°F (20-24°C) with a relative humidity between 60 and 70 percent. Buy a humidity-and temperature-reading device. They are inexpensive and will tell you how far you are off the ideal range.

Use an exhaust fan to remove hot, stagnant air from inside your tent. A constant exchange of cool, fresh air is key. Most grow tents give you the option to install an intake fan at the base, or you can open the mesh windows, which will help bring fresh air in.

If the garden is too hot due to excessive lighting, the plants will respond by ceasing growth and eventually dying. Remove heat judiciously.

The vegetative stage is an opportune time in which to train your plants. During this period, you will be able to perform a number of techniques to improve canopy coverage and overall yield. These methods include tying and bending, pruning, snapping and twisting, ScrOG (screen of green), topping and fimming.

During this stage, plants consume nitrogen, phosphorus and potassium, with nitrogen as the primary nutrient used for leaf growth and some phosphorus used for the root zone.

The Flowering Stage

Now that your plants are strong and healthy, they’re triggered to begin flowering as they respond to shorter days by your changing of the settings on your lighting timer. You’re replicating August through October by giving the plants alternating periods of 12 hours of light and 12 hours of dark, which will get your plants blooming.

Things to Consider: Your plants will go through a transition stage once the lighting regime has changed. This will involve the plants stretching and growing up to 150-250 percent in size by the end of the flowering cycle. The plant’s growth spurt will be most noticeable during the first 3 weeks of flowering.

Just as it’s essential to maintain the correct temperature and humidity in the growing stage, the same is true for the flowering stage. You will want the temperatures at 70-75°F (22-24°C) with a relative humidity of 30-40 percent.

The plants will also need nitrogen, phosphorus and potassium; however, they’ll need phosphorus and potassium more in the flowering stage than in the vegetative stage to help produce buds.

Keep your oscillating and exhaust fans on permanently to prevent stagnant and moist air from surrounding your plants. Poor air circulation can result in mold and mildew on the flowers and foliage of your plants.

An Indoor Grow Checklist for Beginners

Below is a list of the essential equipment for setting up an indoor grow, and the perfect guide for a beginner grower to get started properly.

Choosing a Grow Light

Your choice of a grow light depends on your budgetary concerns, spatial logistics, growing experience and a few other factors mainly based around practicality. The cheapest option is generally a fluorescent system, which uses minimal electricity while producing little heat. An HID (high-intensity discharge) lighting setup such as HPS (high-pressure sodium) or MH (metal halide) is a pricier option that generates more heat, but it also produces fuller, denser flowers. LED (light-emitting diode) technology runs cooler and shows promising gains in production, but it remains an expensive choice due to the initial upfront costs.

Do You Need a Ballast?

A ballast is required when operating an HID lighting system. There are a range of ballasts available, from basic cheaper versions to more high-tech digital models with optional power outputs.

Intake Fan

Intake fans bring in fresh air from the bottom of the grow tent. The intake fan will have a smaller capacity than the main exhaust fan. which is connected to the carbon filter at the top of the tent. An intake fan, which provides fresh air throughout the tent and increases the integrity of the air exchange, is not absolutely essential if your exhaust fan works well and there is a good amount of air being sucked through the filtered vents placed at the lowest parts of the tent.

Exhaust Air Out

Generally, you will want to select a powerful fan to expel stagnant air from inside the grow tent.

This fan is also connected to a charcoal filter, which will control odor. A good exhaust fan will ensure that the airflow in the tent is recycled at a rate that is ideal for the plants, along with temperature and humidity levels.

Carbon Filter for Odor Control

The carbon filter is installed in the upper part of the grow tent, through which the exhaust fan blows the air directly outside and away from the fresh-air intake. Make sure that your filter and fan have the same airflow-rate capacity.

Acoustic Ducting

This silver flexible tubing is what facilitates air movement from the intake fan and the exhaust fan.

A cheap alternative is standard ducting; however, if you spend a bit more, you can invest in a noise-proof version. This is well worth the investment and will distribute the airflow as quietly as possible. When setting up ducting, make sure that there is no sagging to make it efficient as possible.

Plastic or Felt Pots

Traditional plastic pots are cheap and easy to find, while felt pots cost a bit more. Felt pots have their advantages—they keep roots warmer and make pruning them easier—and I would personally advise investing in them as they can be recycled and are much more beneficial to the overall health of the plant roots.

Selecting a Growing Medium

If this is your first grow, then selecting an organic growing medium is probably the easiest solution. There are many “soils” available, but most are actually soilless mixes based on peat or coco coir. I also advise beginning growers to avoid hydroponic growing until they’ve mastered the more forgiving soilless or coco mediums.


You should buy a sufficient amount of nutrients for your entire your first grow, making an effort to cover all the bases in terms of nutrition. There are many nutrient brands available with a wide range of foods covering all parts of a plant’s life cycle. Most nutrient companies provide a grow chart, so you can follow the weekly step-by-step guide, but err on the side of caution and avoid overfeeding your plants.

Temperature and Humidity Monitor

These small displays can fit anywhere and use sensors to determine and display the temperature and humidity of your indoor environment. Some also have the option to check the lowest and highest readings to see if the grow conditions are off in any way, and some even have apps so that you can read the data remotely on your phone.


During the vegetative stage, humidity should be close to 60 percent and decreased as the flowering stage commences. A humidifier generates a fine mist and can be placed either directly in the tent or in the room from where the tent is pulling air.


A dehumidifier will remove the moisture content of the air. This is important during the flowering stage. If you’re pulling fresh air from outside where the humidity is very high, it can cause an imbalance and lead to serious problems.


These pen-size devices measure the parts per million and electrical conductivity of your nutrient solution. It’s extremely important for the grower to have an accurate measure in order to avoid issues with toxicity or deficiencies.

pH Pen

This device measures the acidity or alkalinity of your nutrient solution on a scale of 1-14 (from most acidic to most alkaline). Roots require a certain pH in order to absorb primary nutrients and trace elements. In soil, a solution should have a pH of 6.0-6.5; a hydroponic grow requires a slightly lower pH of 5.5-6.0. You’ll also need solutions to adjust the acidity or alkalinity of your nutrient solution (pH up and down).

Chains and Hooks

I’m old-school and still use chains and hooks for everything. Sourcing precut chain and metal S hooks is an easy task, and you know that you can’t go wrong with metal. Using modern bungee cords and metal wire works well, but when it comes to suspending heavy fans, large-size carbon filters and heavy LED grow lights, chains and metal hooks are the most reliable.

Thick Waterproof Tape

Always make sure you have a thick, waterproof packaging tape to firmly wrap all the connecting parts of your ducting and fans. This will keep everything airtight and waterproof—and it’s just handy to have some industrial-strength tape close by. Plastic cable ties and metal clips also work well; however, thick tape is cheap and easy to find.

Oscillating Fans

Once you have an exhaust fan and an intake fan set up and working, you’ll next want to add some additional airflow at the bottoms and tops of your plants. Oscillating fans will create a gentle breeze that will keep C02-rich air flowing around the leaves.


A timer is required to control all of the electrical devices inside the tent, according to your light regime of either a 18/6- or 12/12-hour day/night light cycle. Carbon filters and fans should be left on permanently. Don’t skimp on your timer, as cheap ones can easily malfunction or break.

Plug Extensions

You can never have too many plug sockets available when growing indoors. To avoid a mess of wires, I personally like to have all my fans connected to one plug extension, which is left on permanently. I have a second separate plug extension for the grow lights and ballast. Some timers are quite chunky and can take up a lot of the space, so having extra plugs is always a good plan.

Spray Bottles

Foliar feeding with water or a mild nutrient solution contributes greatly to a plant’s health and vigor, so it’s a good idea to purchase a few different spray bottles from your local hardware store. Spray bottles become smelly over time, so they’ll eventually need replacing.

White Sticky Labels

I personally like to have a few packs of white sticky labels lying around for when I’m growing many different strains. It can be too easy to mix up the strains, so I avoid any confusion by labeling the pots early on.

Now that you have your equipment, get growing!

Originally published in the April, 2019 issue of High Times magazine. Subscribe right here.

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