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Mar 4, 2022

What Soil Should I Use for Planting Autoflower Seeds?

More and more cannabis growers at all levels, from hobbyist to larger scale commercial indoor and outdoor farmers are discovering the benefits of running autoflower strains. Why? For back yard and/or basement warriors, autoflower strains, also known “day-neutral” strains, are not terribly difficult to grow. Autoflower strains also feature a relatively compact stature. And regardless of the strain, an autoflower will start to flower 30 days after it emerges from seed. And best of all, an autoflower will reach maturity in just 6 weeks!

The decision to run an autoflower in your grow tent or a while field is not one to be taken without proper planning: autoflower strains have the own set of unique cultivation requirements. As such, running an autoflower strain is a strategy (what you’re going to do) requiring you execute against well-defined autoflower tactics (how you’re going to achieve your strategy).

Here’s the thing. Until just a few years ago, when commercial cannabis became fully legal,  autoflower strains remained largely hidden in the cannabis underground in California, where a select few advanced autoflower geneticists were quietly advancing the autoflower arts. Even today, a good deal of mystery exists about growing an autoflower; and very few have adopted an autoflower strategy often for lack of authoritative information. This includes from where you can get reliable autoflower seeds, to how you germinate autoflower seeds, and to what and how much nutrition autoflower strains require. And what kind of deliverable can be expected from an autoflower installation.

The good news is as more growers plant these new autoflower strains, a knowledge base of information related to successful autoflower cultivation is coming to light. And, a select few autoflower cultivators are rising to the challenge of creating reliable feminized autoflower genetics, and are providing some rather kick-ass autoflower strains suitable to both home and commercial autoflower grows.

To best understand what it takes to grow an autoflower strain versus the more prevalent photoperiod strains, it helps to have a basic understanding about why running an autoflower is worthy of your consideration, and what makes an autoflower different from its long-standing cannabis photoperiod predecessor.

While there are many legends of how the first autoflower strains came about and by whom, the genesis of autoflower strains is largely based in economics, and the desire of cultivators to achieve more harvests of quality cannabis in a growing season. It also came from a desire from autoflower growers to beat the majority of cultivators growing photoperiod crops to market: with proper autoflower cultivation management, autoflowers can typically be harvested in mid-summer, well before the glut of photoperiod cannabis products hits the market. As such, autoflower strains have been proven to better hold their value, while giving growers more options and predictability.

Now unknown by many who believe cannabis comes in either sativa or indica varieties of some permutation thereof, a third subspecies of cannabis exists, known as Cannabis ruderalis.

Cannabis ruderalis is a compact plant thought to have responded to the survival of the fittest existence as it grew near the borders of Siberia. Unlike photoperiod cannabis strains that react to the duration of sunlight to create flowers which in turn create seeds and thus ensure their reproduction, Ruderalis genetics respond to the need to survival by triggering the flowering response without a need for a specific light style and/or duration. Ruderalis are tough, and do not require the rich soils of its photoperiod cousins, whose roots were in more tropical climates.

Without getting technical, the first autoflower strains came about by breeding indica and sativa strains with ruderalis plants to create an autoflower breed that exhibited the flower mass and potency characteristics of its indica/sativa parents while providing the autoflower characteristic of fast seed-to-harvest cycles.

Now as you can imagine, given the short season and rather difficult, most often peat-based soils in which ruderalis strains grew required it to adapt to survive.

So it is when a grower wants to cultivate an autoflower strain. The fact is, while not all autoflower strains are alike, for the most part, an autoflower will prefer a grow medium that is light and not compacted as many commercially available grow mediums used for the autoflower’ cousin photoperiod strains.

What’s more the ‘soil’ you use for an autoflower strain is typically low in resident nutrients; in no instance should a ‘live’ soil or even a dense and rich organic soil be used or you’ll burn the autyoflower root zone in no time at all

Rather, when growing an autoflower, it’s best to have control of the inputs of water and nutrition so the autoflower can recognize and respond on its own volition to its flowering instincts.

And indeed, it’s very important you manage watering an autoflower. You see, an autoflower plant can easily be “drowned” when its root zone is deprived of oxygen. In fact, an autoflower really hates excess moisture and as such, should be allowed to dry somewhat (but not ever fully) so its roots reach out for sustenance.

Thus, when establishing an autoflower, its best to use a peat-based ‘soil-less” medium such as Pro-Mix, with light amendments to bring up its nutritional value. Because to be sure, an autoflower does require water and fuel to grow; but most autoflower strains will always require less inputs than tropical strains.

One such amendment for autoflower propagation is worm casings; another would be a rich organic soil. However, you don’t mix it with the primary autoflower ‘soil’ as you would for a photoperiod. Rather, when preparing a pot, ideally one with breathability such as a fabric or air pot (to encourage autoflower root zone oxygenation), layer the pot with a base of drainage pebbles, then add a layer of worm casings or rich soil, and top with at least 50% of a soil-less or loosely packed medium.

Once you’ve transplanted your early autoflower starts, water around the stalk of the plant so the autoflower roots reach out for moisture. Real care should be given to the pH of your water: it’s critical to stay within the 5.8 – 6.6 range so microbes in your grow media can convert form an autoflower can uptake and use for growth. In this case, a simple pH meter is an indispensable tool for guarding the health of your autoflower.

Now one of the biggest temptations for autoflower growers is to over-pander to them. Resist this temptation at all costs. Which is not to say you should ignore the care of your autoflower strains; you should not.

But, like all plant growing endeavors, growing a quality autoflower is all about paying attention to your ‘ladies” and how they react to inputs, including light.

Do so, and your autoflower adventures will yield the magical outcomes of your dreams.





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