As cannabis growers, we’re always looking for what’s best for our lovely little cannabis plants so that they can grow bigger and lovelier. Of course, the result is always worth it when the yield is excellent, but how do you do that?
If you are a new grower, the obvious way is to ensure you get the three things right — the growing medium, lights, and environment. Here’s a quick starter guide on what’s best for your cannabis plant.
Hydroponics vs Soil: The Best Growing Mediums
One of the first decisions you make for growing your cannabis plant is the type of setup you’ll be using, whether it is hydroponic or soil.
Growing cannabis in soil is the most basic and natural way of growing cannabis. It’s easier to set up and grow, and since soil is already rich in nutrients, you don’t have to worry too much about feeding your plant. Sometimes, even tap water works just fine.
If you are growing cannabis outdoors, soil is what you should go with, no questions asked. If you’re lucky, the soil in your backyard is good enough to sustain your cannabis plant and you only need to pay attention to the plant without worrying about the growing medium.
But soil has its downsides. Soil-based plants don’t give you so much control over the growth and it makes cannabis vulnerable to various soil-based pathogens like fungus, mold, and pests.
You can even choose hydroponics, especially if you are growing cannabis indoors and want the utmost control over your plant’s growth. There are various types of hydroponic systems, and depending on the type you choose, it could be very easy or tricky to set up. Some of them are dirt cheap, whereas other sophisticated systems are expensive, so it depends on your goals. However, the results are worth it and the yield can be high-quality.
Hydroponics also solves various downsides you may come across with soil in your backyard. With a hydroponic setup, you don’t have to worry about soil compaction, soil-based pathogens, and other factors that may affect your plant’s health if grown in soil.
But choosing between the two options comes down to the growing medium you use, and there are many types of growing mediums. Let’s take a look at some of the best growing mediums you can use for growing cannabis.
1. Soil
As mentioned earlier, soil is the easiest and cheapest way of cannabis cultivation — it’s how the plant has evolved into existence over millions of years. You can never go wrong with nature.
Yes, hydroponic plants can have a better yield but that doesn’t mean soil-based cannabis produces poor yields — if you use the right approach, even the most basic soil will surprise you. Additionally, soil is easy to work with so it’s often best for beginners or those who don’t want to invest much into their cannabis operation.
Soil has other benefits, too. If you’re using high-quality soil, pH fluctuations are rare. Plus, the soil is easy to source even if you live in the remotest regions — gardeners are everywhere. Soil is also the best route to take if you want to grow cannabis in a natural, organic manner.
Some downsides of soil include a higher risk of mold, pests, or fungus. Plus, soil offers less control, and sometimes cannabis grows slower in soil.
If you want to use soil to grow cannabis, you need to be a little picky with the process so you get the best results. For that, you need to pick soil that is light and has a loose texture, which promotes root development and oxygen retention.
Additionally, the soil must have high drainability so water doesn’t collect within, preventing chances of mold and nutrient lockout. Lastly, the soil should be rich in nutrients; hence, the best soil to pick should be living soil.
2. Perlite and Coco Mix
Perlite and coco coir mix is an excellent alternative to soil for growing cannabis, but individually, perlite and coco don’t work so well.
Perlite is produced from obsidian, a volcanic rock type, and the production process makes this product moisture-free and rapidly expandable. It’s inert, light, and airy — think popcorn — and it brings excellent oxygenation benefits. Plus, it has no interaction with nutrients.
On the other hand, coco coir is made from coconut husks. This eco-friendly growing medium offers decent water and air retention while allowing the roots access to nutrients. And it’s difficult to overwater coco coir and you can even get away with a smaller pot without affecting root development.
Put the two growing mediums together and you have a medium that’s excellent for cannabis cultivation. The biggest advantage of perlite and coco mix is that they allow easy root development — your cannabis will grow big and tall with this mix.
You also get control of the nutrient levels so your plant grows exactly how you want it to. You also don’t need to invest in any special equipment for using this mix, except for a pH meter. And the medium is as easy as soil to use even for beginners.
The downside? It lacks nutrients, so you need to be on your toes about the nutrients, and you need to monitor the pH levels regularly. This mix may also be difficult to source in some regions.
To create a perlite mix, you need to keep the ratios in mind. Ideally, the best ratio is 60:40 or 70:30, depending on your local climate and cultivation goals.
3. Expanded Clay Pellets
You may already know clay pellets by another name, like hydroton, clay pebbles, or lightweight expanded clay aggregate (LECA), but they all mean the same thing. These tiny pebbles are made from clay, and the expanding and heating process makes them porous and light.
This growing medium is known for its excellent aeration, which supports root development and water retention. This also makes clay pellets the right choice for hydroponic cannabis setups.
Because of their porous nature, clay pellets are also less likely to develop blockages, so the water drains well all the time. They also have a neutral pH and harbor microbial population, which is not present in other soilless growing mediums. You can also recycle or reuse them easily.
On the flip side, clay pellets don’t have the best water-holding capacity — it’s decent but not good enough. And they are expensive. Over time, they can also cause plumbing problems in your hydroponic setup.
4. Rockwool
Rockwool is a fascinating medium that is often tricky to use, but if you get it right, it can produce excellent results in terms of plant growth and health. The medium was invented to be used as insulation in construction, but it has become many growers’ favorite growing medium.
Rockwool is made from basalt salt, which is treated with extremely high temperatures and spun like cotton candy. As a result, it has excellent water retention and is completely inert, making it suitable for hydroponics.
Since it is sterile, you don’t have to worry about diseases, pests, or infestations as much. And rockwool also gives you tremendous control over the nutrient delivery of your cannabis plant, so you can make your plant grow like you want.
The downside is that rockwool lacks any nutrients and you have to add them; plus the pH tends to fluctuate sometimes. It is also not completely organic since it does not biodegrade well and recycling it isn’t always recommended.
pH of the Growing Medium
You may use the best growing medium there is but if the pH of it is not right, your cannabis plant will not benefit from it much. In fact, pH is one of the most important aspects of growing cannabis as it dictates how much nutrients your plant can access from the growing medium.
pH means hydrogen ion concentration in the nutrient solution, representing the acidity and alkalinity of the solution. However since the scale is logarithmic, even small changes in the pH can significantly affect the nutrient uptake.
This is why the pH level is crucial for your nutrient uptake. If the pH of the growing medium is too acidic, micronutrients like iron and manganese become more soluble, which can cause nutrient toxicity or lockout. On the other hand, too low pH can cause nutrients like phosphorus to become less soluble, leading to nutrient deficiencies in your cannabis plant.
The pH level of the soil or growing medium directly affects the plant's ability to absorb nutrients. Cannabis plants thrive in an acidic to neutral pH range, typically between 6.0 and 7.0. Within this range, the nutrient uptake is optimal. Thus, the plant can absorb a balanced combination of macronutrients (nitrogen, phosphorus, potassium) and micronutrients (iron, zinc, magnesium). However, if you deviate from this range, it can result in deficiencies or toxicities that hinder plant growth and compromise yields.
Maintaining a balanced pH level not only benefits nutrient absorption but also influences beneficial microorganism activity in the soil. Microorganisms play a role in the decomposition of matter releasing essential nutrients and forming beneficial partnerships with plant roots. So, if you maintain the proper pH level, it creates an environment that supports the growth of these microbes, leading to a strong and healthy root system that improves nutrient absorption and disease resistance.
Remember that the pH of the water you feed to the plants is also important as it can affect the plants gradually, even if you haven’t mixed in nutrients. To avoid issues, measure and adjust the water’s pH before you water the plants.
If you’re new to growing cannabis, you should know that the pH range varies slightly for soil and hydroponic mediums. Your aim should be to adjust the levels accordingly, depending on your chosen medium.
Here’s a quick overview of maintaining the right pH for most types of growing mediums:
1. Soil
If you’re using soil to grow cannabis, the ideal pH ranges between 6 to 7. Although pH is important, you don’t have to obsess too much about the numbers. Remember that you need to maintain a range. Therefore, if the pH is, say, 6.3, you don’t need to get it to 6 or 7. Coming to the fertilizers you use, they play a key role, so make sure you use nutrients from reputed brands. Many growers don’t check the pH if they are using organic nutrients; however, you should still check the pH even with organic fertilizers just to ensure that it doesn’t deviate too far from the range.
If you’re using organic soil or super soil you made at home, you don’t need to check the pH frequently. However, note that this applies only to good composted soil. Growers also refer to it as “cooked” soil where the microbes have the chance to break down the nutrients gradually.
If you put in the effort to source good soil and mix them with nutrients beforehand and let them cook for at least a couple of months, which is known as super soil, pH will not be a big headache for you. But, if you start noticing issues like nutrient deficiencies, you will need to check the pH frequently because although the symptoms could match a deficiency, it could be a pH imbalance.
On the other hand, if you choose to grow cannabis in the soil you’ve purchased from companies, remember that you will need to feed nutrients at least once a month as the plants may have used up all the nutrients.
2. Hydroponics
The ideal pH for hydro is about 5.5 to 6.5 for the plants to uptake nutrients successfully. Since you’re growing in water, there’s an absence of microbes that aid the plants to absorb nutrients. In soil, these microbes do most of the work and help the plants, but hydro doesn’t have that option, so you need to be more cautious and keep an eye on the levels.
If you neglect the pH, the plant will face severe consequences, and this is true even if you’re growing in soil. Remember to clean your reservoir consistently to prevent salts from building up and creating pH imbalances. Many people avoid cleaning the reservoir because it takes some elbow grease but if a nutrient like calcium starts building up, your plant will start experiencing a range of problems.
We already mentioned that hydro growers should be more cautious about the pH. This is because it’s not as forgiving as soil. Soil has pH buffers that adjust when there’s a slight change in the pH, but the same won’t happen with hydroponics. Therefore, maintain the levels between 5.5 to 6.5 at all times so the plants don’t struggle.
Also, remember that you need to be careful while adding nutrients. Adding extra nutrients of one type will cause several problems. For example, everyone tells you to add calcium whenever you can as it helps the plants grow healthy, However, too much calcium can cause magnesium deficiency and create other issues.
3. Soilless Growing Mediums
Any growing medium that doesn’t include soil is called soilless media, and this includes coco peat, coco coir, etc. Instead of growing plants in the water, some growers choose these mediums. If you’re using only soilless growing media, maintain the pH between 5.5 to 6.5 just like a hydroponics setup. But, if you add some soil (yes, some growers mix coco coir and soil) to it, you must maintain it between 6 and 6.5. You will have to experiment and go with what works for you.
To test the soil pH, invest in a good digital pH meter. It’s not all that expensive, compared to how much you spend on other equipment. Calibrate it regularly to get the best results. Some growers use strips but they may not be as accurate as digital meters. If you want to be absolutely certain of your soil’s pH, you can take it to a lab and get it tested but it’s unnecessary if you’re a home gardener. Whatever method you choose, follow the instructions carefully.
If you identify pH fluctuations, purchase pH Up or pH Down solutions from your local nursery or online and use them accordingly. Other options for soil growers include lime to raise the pH gradually, and sulfur to decrease it. Check the pH of the plants before planting them and wait for a few hours to recheck their pH again. You should follow the same procedure even when you’re watering the plants. Collect the runoff water in a small container to check the pH. The best way to check the pH is to test the nutrient solution’s pH and run-off water’s pH and compare the results. This may seem like a lot of work, but it gets smooth after a while.
Maintaining the pH level in a hydroponic system is equally important. Like soil, pH affects plant health significantly. Therefore, you need to test and adjust the pH regularly. To do so, start with a good digital pH meter. As mentioned earlier, you need to check the pH regularly, meaning you need to do it at least once every day.
Follow the guidelines provided with your pH meter if you’re unsure about how to use it. Remember to start with a high-quality water source when setting up your system. If the pH of your water source is not ideal, make adjustments before adding nutrients to ensure great conditions for your plants.
If the range is between 5.5 to 6.5, everything is good. If not, adjust the pH back to normal ranges. For hydro growers, pH Up and pH Down solutions are your best friends. However, make sure you do it slowly. As the solutions are very effective, the pH can shift up and down erratically.
Thus, add the solution that adjusts the pH to your reservoir in increments at first. Mix it well, then test the pH again. This gradual approach prevents over-adjusting. Keep adding drops of pH Up or pH Down until the pH gets back to your range. Wait for a while and retest it again as it may take some time for the adjustments to stabilize. If this is too much work, you can go for automated controllers that regulate and maintain pH levels automatically.
Also, if you notice any signs of deficiency or pH issues frequently, flush the system whenever possible to remove buildups.
Optimal Lighting Conditions to Grow Cannabis
When tuning in the best lighting conditions, you need to focus on a few things: the type of light, the spectrum of light, light intensity, and distance from the plant. Let’s dive in.
1. Best Type of Grow Lights
When it comes to growing lights, you have a few options, ranging from really cheap to super expensive. Let’s look at some of the best ones and what may make them ideal for your cannabis operation.
CFLs stands for compact fluorescent lights, the most common type of bulbs you can even buy at your local grocery store. These lights are cheap and last long enough for a growing season, making them ideal for beginner growers. Plus, they are fairly easy to set up without requiring additional equipment.
The downside of CFL grow lights is that they have low light output so aren’t always what’s best for cannabis if you’re growing multiple plants. Their short lifespan means they’ll need replacing more frequently.
HIDs or high-intensity discharge lights include high-pressure sodium lights and metal halide lights — the latter produces cooler light compared to the former. This type of grow light is preferred by advanced growers since they have an excellent light output and are relatively easy to set up. This is the light to choose if you want to maximize your plant’s yield.
They do have a few downsides — they consume a lot of energy and produce heat, so you’ll need to add vents and fans to keep the grow room cool, and they tend to degrade over time and need replacement after each growing season.
LED grow lights are great for growing cannabis, and the high-quality ones even allow you to tune in the spectrum, intensity, et al. via a control switch. These lights are super efficient and last for over a decade with minimal maintenance, and they produce excellent PAR light for the best results. Some LED lights also produce UV light.
The downside is that LED grow lights can be expensive — worth it since they are what’s best for cannabis — and since there is a lack of industry standards, you have to invest some time in picking the right LED grow light for your setup.
2. Distance from the Plant
The next thing you need to fine-tune is the grow light’s distance from the plant. If the grow light is positioned too close, your cannabis may experience a light burn, and if it’s too far, it may not get enough light to grow well, leading to stretching or poor growth.
The right distance depends on the type of light you use since all light types produce different light output. This is why it is recommended that you pick grow lights from reputable brands as they come with a chart with recommended distances for optimal cannabis growth.
3. Light Intensity
Next, you need to focus on the intensity of the light. Poor light intensity can lead to slow growth or larfs (airy buds) since the plant will not produce enough light to sustain its development. On the other hand, if the light is too bright, it can burn the plants.
Here, it’s best not to rely on the light’s wattage, especially if you are using LED grow lights. For example, a 100W LED will not produce the same quality of light as a 100W HID or CFL grow light.
Instead, you need to use PPFD for this. PPFD refers to photosynthetically photon flux density, i.e., the amount of PAR light at a specific surface in one second. You can measure this with a lux meter and convert the reading.
So, what’s best for cannabis in terms of PPFD? 308 to 617 μmol in 18 hours for a vegetative plant on an 18/6 light cycle and 462 to 926 μmol in 12 hours for a flowering plant on a 12/12 light cycle.
Light cycle refers to the amount of time your cannabis plant is exposed to light during a day, especially if you are growing photoperiod cannabis plants. For seedlings, you should stick to a 24/0 light cycle (24 hours of light and 0 hours of darkness. For vegetating cannabis, the best light cycle is 18/6 and for blooming cannabis, it is 12/12.
Some growers even recommend using a 24/0 light cycle for vegetative cannabis plants since more light means more energy production, but some strains cannot handle that well. So, try your hand at it and if your strain handles it, you can use a 24/0 light cycle during its growth stage.
Finally, you shouldn’t ignore the color spectrum, either. The color of the light can have a tremendous impact on how your plant grows. This is because some colors influence the photosynthetic process better than others, leading to much better plant growth.
For seedlings and vegetative plants, it’s best to pick lights that are blue-dominant or cool, and for flowering plants, you should pick grow lights that are red to far-red in color.
Humidity and Temperature for Best Cannabis Growth
Temperature and humidity are crucial for a healthy cannabis plant, and if the two climate conditions are not right, your cannabis plant may experience stress along with the risk of mold, drying out, or other harmful conditions that can significantly affect the yield. So, let’s take a look at what’s best for cannabis in terms of temperature and humidity.
1. Ideal Temperature
Temperature is crucial for cannabis as it influences the efficiency and speed of various processes like transpiration, respiration, photosynthesis, germination, and flowering. If the temperature is ideal, the plant grows well, but if it’s too low or too high, the plant will struggle to reach its potential.
For example, a study found that if the temperature is too high for cannabis, it can significantly impact photosynthesis and water use, resulting in poor growth and yield.
So, you must stick to the right temperature range for your cannabis plant, which is:
- 65°F to 70°F (18°C to 21°C) for propagation
- 76°F to 78°F (24°C to 25°C) during the day and 65°F to 68°F (18°C to 20°C) during the night for the vegetative stage
- 72°F to 85°F (22°C to 29°C) during the day and 55°F to 70°F (13°C to 21°C) during the night for the flowering stage
There are many ways to control the temperature, but for a basic setup, you can use a small fan to keep the air fresh and cool. You can take it to the next level by using air-con, heaters, coolers, etc. to warm or cool the air as required. If you want the best results, invest in a smart thermostat — it’ll automate the process.
2. Ideal Humidity
Similarly, humidity is important for cannabis growth, too. The right humidity dictates how much water your plant will give out to the environment. If the humidity is high, the water concentration gradient will drop — the plant will lose less water. If the humidity is too low, the same rises, leading to more water loss in the plant.
Additionally, humidity comes in handy to prevent serious ailments like mold fungal infections, and even some pests. High humidity is a breeding ground for some pest species and fungal spores also thrive in such environments. So, if the humidity is too high, it won’t take long for your cannabis plant to suffer from mold, slimy roots, bud rot, pests, etc.
So, the best humidity levels for cannabis plants are as follows:
- 65% to 70% during the seedling stage
- 40% to 70% during the vegetative stage
- 40% to 50% during the flowering stage
As you see, you will be reducing the humidity as your plant grows from one stage to the next, but don’t switch from 60% to 40% in a day — your plant will experience stress. Instead, you need to progressively decrease the humidity by 5% every week until you reach the desired level. At the same time, increase the temperature slightly.
Here are some ways to increase the humidity:
- Use a spray bottle or mister — won’t last long but works in a jiffy
- Keep the soil moist, not wet
- Slow down the fans in the room
- Hang damp towels around the grow room
- Get a humidifier
Here are some ways to decrease the humidity:
- Speed up the fans and exhausts
- Add more fans, including an oscillating fan
- Water the plants before you turn the lights on
- Get a dehumidifier
3. Add Carbon Dioxide
If you’re wondering what’s best for cannabis, one such thing is adding more CO2 to the grow room. Cannabis plants extract CO2 from the air via stomata, and it uses the heat from light to convert it to oxygen and glucose.
On average, a grow room contains 410 particles per million (ppm) CO2, which is enough, but if you want bigger plants, you can always add more CO2. Just don’t go overboard with it as it can choke your plant if you’re not careful enough.
You can add more CO2 to the grow room by using CO2 generators that use propane or natural gas, compressed liquid CO2 canisters with valves, dry ice, compost, sodium bicarbonate and vinegar, etc.
For the best results, add 1,200 to 2,00 ppm of CO2 to the grow room — this will make your cannabis grow by up to 20% bigger in size. Anything more is an overkill, literally for you, and not worth it.
Summary: What is Best for Growing Cannabis: Growing Medium, Lights, Environment
The growing medium, grow lights, and the environment are three crucial aspects of growing cannabis. These things can make or break your cannabis operation, so it’s best to start with them.
The right growing medium will support your plant and encourage excellent root development. The right kind of grow lights will enable the plant to produce more energy. An ideal temperature and humidity level will ensure your plant stays comfortable, carries out its processes properly, and prevents unnecessary risk of mold, fungus, or pests.
But this is just the beginning. Stay tuned for more things you need to keep in mind for the best cannabis results.
