For centuries, cannabis strains have naturally grown in soil. Indeed, this plant grew so well in so many regions that it has earned the nickname “weed.” Despite the recent innovations in hydroponics, many home cultivators prefer using old-fashioned soil to grow their ganja indoors.
Although cannabis plants are reasonably resilient in many soil types, that doesn’t mean they don’t have preferences. You could grow a healthy cannabis plant using a random soil blend at your gardening shop, but that’s not an excellent strategy for success.
To stack the odds in your favor, you should always go with a soil blend with the qualities cannabis plants respond well to.
Taking a few moments to review the best soils for cannabis will help you choose the best option for providing your marijuana with an ideal growing medium.
The “Dirt” On Cannabis Dirt — Key Features To Watch Out For In Cannabis-Grade Soil
There are a lot of discussions online over the “best dirt” for cannabis plants. Many seasoned cultivators will try to convince you that their unique blend of fertilizers is the only way to grow delicious cannabis nugs. However, for most beginner cultivators, it’s easiest to focus on readily-available potting soils with a loamy texture.
Indeed, many first-time cannabis cultivators do fine with a bag of affordable potting soil tailored for fruiting plants (especially tomatoes). Since tomatoes and cannabis have a similar growth pattern, any soil formula designed for this fruit will probably work well for weed.
As we just mentioned, the soil you choose should have a “loamy” texture. What does that mean? “Loam” describes a type of soil with traces of sand, silt, and clay particles. The mixture of these soil types helps loamy soils retain and drain water. Cannabis plants perform best in soils with moderate soil retention and drainage, which fits loam’s consistency to a tee.
When you hold high-quality soil for cannabis in your palm, it should feel loose and light with a slightly spongy texture. If the soil feels too dry, powdery, or hard, it’s probably not an excellent choice for your cannabis grow room.
In addition to drainage concerns, high-quality cannabis soil should have plenty of active nutrients. Just be careful not to go crazy adding amendments and fertilizers if you’re new to weed cultivation.
Yes, cannabis can benefit from nutrients in the soil, but it’s more common for cultivators to give their plants too many nutrients than not enough. Cannabis can only absorb so many nutrients before it starts blocking them out. Incredibly nutrient-dense soils can easily lead to a condition known as “nutrient burn,” which may result in stunted growth.
As long as you have some supplemental nutrients, you shouldn’t be super concerned with buying the most ultra-nutrient-filled soil — at least not until you have more experience growing cannabis in organic soils. You could always adjust for potential nutrient deficiencies during the growth process with standard NPK supplements.
Does Cannabis Soil Need A Certain pH?
Regarding nutrients, it’s essential to scan the pH of whatever soil you want to use for your cannabis plants. The pH of your soil will directly affect how well your cannabis plant’s roots can absorb nutrients like nitrogen and potassium. You will run into trouble as your cannabis plant matures without a proper pH score.
Your soil should maintain a pH level of 5.8 – 6.2 throughout all stages of growth. Please adjust the pH of your soil with supplements until it reaches this range before planting your cannabis seeds.
Is It OK To Use Coco Coir For Cannabis Soil?
Although most cannabis cultivators recommend a simple loamy potting mix, coco coir has become an increasingly popular growing medium in recent years. Unlike soil, coco coir has zero nutrients, so it’s more similar to growing in a hydroponics unit.
Some people enjoy coco coir because it tends to be more pest-resistant than traditional soil mixtures. Also, since coco coir is a “blank slate,” it may help cultivators who desire optimal control over their nutrient additions. You may also want to try coco coir-rich soil before deciding whether hydroponics is the right move for you.
On the flip side, many argue there’s no clear benefit to using a coco coir mix over regular potting soil. Sure, coco coir may have extra pest resistance, but it tends to make growing unnecessarily challenging for many home cultivators.
Since there are no nutrients in coco coir, growers must invest in many macro and micronutrient supplements. It’s also more common for cannabis plants grown in coco coir to develop strange micronutrient deficiencies.
One of the benefits of growing in potting soil is that you can take advantage of the natural nutrients in this medium. Many cultivators argue these extra nutrients create more “buffer room” for errors, and they take the stress out of fussing with micronutrients. Coco coir won’t give growers any “buffer benefits,” so cultivators must be incredibly vigilant on their nutrient schedule and pH adjustments.
All that being said, there’s nothing “wrong” with opting for a coco coir/perlite soil mix. However, most inexperienced cultivators should only consider coco coir as an amendment to help improve soil retention.
Do You Need A Different Soil Type For Autoflowers?
Typically, autoflowering strains perform well in the same loamy potting mix you’d use for photoperiod cannabis hybrids. However, some cultivators point out that autos can’t handle as many nutrients as regular weed strains.
The Cannabis ruderalis species in auto strains grew up in areas where soil conditions are less than ideal. Ruderalis plants evolved in Russia and Siberia, often in nutrient-depleted soils like peat moss.
Since ruderalis doesn’t have as much experience pulling tons of nutrients from the soil, it tends to “lock out” nutrients quicker than photoperiod strains. For this reason, auto cultivators must have a light hand with their nutrient schedule. Avoiding too many amendments and fertilizers in soils for auto plants is also best.
You don’t have to use nutrient-depleted soil mixes like coco coir or peat moss, but you could if you’re experiencing issues with regular loamy potting soil.
If you’d like more advice on growing autos at home, please check out International High Life’s previous “Autoflower Guide.”
Is Growing Cannabis In Soil Superior To Hydroponics?
Dirt is the default for many cannabis cultivators, but there are other options you could consider. Indeed, there’s now a heated debate between soil and hydroponics growers over which method of cultivation is “better.”
For people who aren’t aware, hydroponics refers to “soilless” growing mediums that use water, air pumps, and supplemental nutrients to grow plants. Most hydroponics units place plants in inert materials like rockwool or coco coir to keep their roots sturdy as they absorb the nutrient-rich water.
Determining whether hydroponics is “superior” to soil depends on many factors, including your expected ROI and previous experience. In most cases, hydroponics will reward growers with a faster & bigger yield, but they require more expertise. Soil may not reward cultivators with as quick returns, but it’s more “mistake-proof.”
Please remember that hydroponics contains virtually zero nutrients. You’ll need to invest more money in hydro-specific nutrients and use more of these supplements than soil set-ups. This not only makes hydroponics more prone to minor nutrient errors, but it also makes them more costly to maintain versus soil set-ups.
With high-quality potting soil, your plants will have access to many natural nutrients. As long as you use your vegetative and flowering nutrient mixes, there’s less risk your soil-grown weed will experience severe nutrient issues. Also, it’s easier and cheaper for most home cultivators to set up a soil mix at home.
Anecdotally, many people claim marijuana that’s grown in soil has a more “natural taste” than “chemically” hydroponics cannabis. However, this observation is more a matter of personal preference.
Every cultivator will have a different opinion on the soil vs. hydroponics debate. If you’re starting with cannabis cultivation, most people will recommend starting with soil because it’s more readily available & “mistake-proof.” Once you have a few successful soil grows under your belt, you may want to consider dabbling with hydroponics to seriously consider this water-based growing style.
For Lit Cannabis Nugs, Stick With Loamy Soil
There are many “special sauce” soil recipes on hot cannabis forums. While there’s no question that “living soil” can produce spectacular pot, it’s not the best strategy for a total beginner. If you’re getting into at-home cultivation, you should stick with a familiar potting mix with a loamy texture. Potting soils that work for fruiting plants will be fine for your first cannabis grow.
Just remember to pay careful attention to your soil’s pH level before planting your weed seeds. We can’t overstate the importance of frequent pH checks, especially for beginning cultivators. Many “nutrient issues” home-growers experience when cultivating cannabis result from improper pH management. Always keep your soil slightly acidic to avoid potential issues with nutrients.
For more pertinent facts about pH, check out our recent post on “Yellow Cannabis Leaves.”