Since the dawn of agriculture, humans have sought to improve the quality of the soil they grow in through the processes of conditioning and amending. While the earliest cultivators may have discovered that adding certain substances to their soil improved their crop, they could not have known exactly why. Thanks to the discoveries of our forefarmers though, many dating back millennia, we have a clear understanding of the systems and substances necessary to produce a truly super soil. In this week’s segment, we’ll get down to the nitty-gritty of super soil with the details that will help you determine if it’s right for you and a recipe you can try if you decide it is. Plus get the coupon code of the week for super soil savings!
The goal of super soil is to create a soil environment ahead of planting that contains all of the nutrition your plants will need throughout the entire grow cycle. It sounds simple, but it’s not as easy as adding a bunch of different nutrients to a bag of potting mix. Heavy-feeding plants such as fruiting annuals require a lot of fertilizer to produce worthwhile yields, and simply dumping a cycle’s worth of amendments in your soil will most likely result in nutrient burn and a failed crop. So how do we add all of the nutrients plants will need ahead of time without burning them up? It turns out that the only way to effectively accomplish this is via the same organic processes that make it possible in the natural environment. This requires not only the proper nutrient ingredients but also a little help from beneficial microbiology, as well as some unique planting strategy and additional preparation time.
Before we even get to the ingredients, it’s important to understand the importance of beneficial biology in super soil. Beneficial microorganisms are the centerpiece of any successful super soil, which is why it is also referred to as ‘living soil’. Plants themselves actually have an amazing ability to regulate the microbial activity around their roots by excreting compounds that attract friendly microbes to the rhizosphere. This also changes throughout the grow cycle to meet the plants’ needs at any given time so supplying a diverse range of beneficial microbiology is absolutely essential. Existing in a symbiotic relationship with the plants, beneficial fungi and bacteria will carry out the breakdown and transportation of organic nutrients within the soil over time, allowing the super soil process to work. Without them, plants will simply be unable to extract the fertilizers you provide. An example of soil biology at work can be seen in our diagram of the nitrogen cycle below, which illustrates the involvement of bacteria and fungi in the process of creating plant-usable nitrogen compounds.
When executing a proper super soil mix, it may only be necessary to add water to achieve a harvest, but most growers prefer to continue to add beneficial biology because it can only improve yield potential. This will not only ensure the continued breakdown of organic material into plant usable form but also help to ensure a balanced pH in the rhizosphere and boost resistance to pests and pathogens. A healthy microbe population many can be maintained with regular applications of compost tea such as Stump Tea or various other forms of inoculants including Great White, Roots Organism XL, Mammoth P, Photosynthesis Plus, or homemade tea brews. All of these options contain various beneficial bacteria and/or fungi that will sustain the processes that make super soil work.
A wide variety of materials go into creating a soil mixture that can provide sufficient vitamins, minerals, nutrients, and microbiology to nourish your plants from start to finish, but it’s important to start with a good base. Some growers prefer to start out with a high-quality premixed organic soil such as Fox Farm's Ocean Forest soil, Roots Organics potting soil or Pro Mix BX. Others who seek to have more control over the exact content of their super soil prefer to use inert base mediums such as sphagnum peat or coco coir. In either case, the goal is to start with a base that drains well and offers an excellent environment for beneficial biology to thrive in.
To build upon your super soil base is important to incorporate both slow and fast release amendments to ensure the proper nutrients remain available throughout the entire grow cycle. This is why many recipes call for multiple forms of the same base nutrient. Further, many amendments actually offer benefits beyond the central nutrient(s) they offer. For instance, soybean meal is not only a good source of slow release nitrogen but it also contains amino acids. Dolomite lime is an excellent source of slow release calcium/magnesium and is also used as a pH buffer. The list of usable amendments for making your own soil is extensive but some of the most common include guanos, humic acid, worm castings, rock phosphate, blood meal, feather meal, bone meals, fish meal, guanos, crustacean shells, kelps, potash, gypsum, limes, and other minerals. When choosing your amendments, some consideration should also be given to the exact type or variety of plant you will be growing. Slightly different nutrient preferences can exist even among strains of the same plant type, so your ingredients should be tailored as closely as possible to your plants’ specific needs.
After you’ve chosen a base and gathered your desired amendments, it’s time to get cooking - "time" being the operative word here. Just as in nature, much of the nutrient content in the organic ingredients you’re adding to your super soil are not immediately available for plant uptake. Time is required to allow beneficial microorganisms to break down the raw organic material into plant-usable form. In the indoor growing world, this process is often referred to as ‘cooking’, which is essentially just another term for composting. Ingredients are first combined/mixed on a tarp or in a bin and water is added while continuing to mix until the material has a detectable and uniform moist (not damp) feel. After mixing is complete the soil is covered in a container or under a tarp to retain moisture and accelerate the process.
Depending on the recipe you use, recommended ‘cook’ or composting times can still vary from 30 to 90 days with the general rule being - the more time, the better. In terms of grow cycles, this is a significant amount of time for preparation, but it can be offset somewhat, especially if you’re starting out with a nutrient-rich base potting soil, and this is where the unique and strategic planting/transplanting aspect of super soil comes in. The key is that your complete super soil mix will not be used until you are nearly ready to enter the fruiting or flowering stage of growth. Much of the nutrient content your plants will require for vegetative growth will already present in the mix, whether you're using a vegetative version of your soill mix or a pre-amended mix such as Ocean Forest or Roots Organic soil, whereas the super soil will be too nutrient-rich for young plants.
The general planting/transplanting strategy is to grow in the base or a vegetative-amended version of the base until it’s time to transplant to the final container. During the final transplant, the super soil will be added first so it is at the bottom of the container. A thin layer of the base is then added on top of the super soil layer, and the base is also used to fill in around the transplant. The base layer/fill acts as a transition zone that provides some nutrient value without increasing stress on top of that resulting from the transplant. Roots will then continue to grow and tap into the super soil layer. If the process is executed properly, you should be able to achieve a great harvest by only adding water and/or your preferred inoculants (recommended) such as Stump Tea to the soil from here. Keep in mind, while you won’t have a regular feeding regimen, that doesn’t mean you will have no maintenance at all. Other factors such as pH should still be monitored and adjusted as needed.
There are many different super soil recipes, with some being far more complex than others. All are based on the same principle though - to provide all of the nutrition needed to complete the grow cycle and produce an awesome organic harvest. Again, knowing your plant variety’s nutrient habits will help you narrow down the choices. Ready to give it a try? The following is one of the most popular recipes in circulation and is based on the original super soil theory. This recipe makes just over 14 cubic feet of soil or enough for around (8-10) 7 gallon smart pots or nursery pots (remember, you are only filling the containers about half full with the super soil mix) so you can scale this up or down depending on how much you need:
- 14 cubic feet of high-quality potting soil
- 1 cubic foot worm castings
- 2.5 lbs. bone meal
- 2.5 lbs. fish bone meal
- 5 lbs. high phosphorus bat guano
- 5 lbs. blood meal
- 3 cups oyster shell
- 3 cups kelp meal
- 3 cups alfalfa meal
- ¾ cup Epsom salts
- 1 cup agricultural lime
- 2 cups Azomite
- 2 tbsp. granular humic acid
- 2 tablespoons mycorrhizae / compost tea mix
- Mix all ingredients, moistening slightly until moist, not damp. Once thoroughly mixed, transfer to several covered container(s), i.e., totes/garbage cans or simply cover with a tarp. Allow a minimum of 45 days, up to 90 days to ‘cook’ or composting time before use.
- After the mixture is properly composted, fill planting containers approximately halfway with the super soil mix and add an inch or two of the base mix on top. Transplant into the final nursery pot and finish filling with base soil. From here, just amend with compost tea until harvest.
If this sounds like more than you’re willing to take on, but you still want to give super soil a try, the good news is that there are more and more readymade super soil mixes available such as Detroit Nutrient Company’s (DNC) Great Lakes Water Only. This and other super soil mixes are formulated in the same manner as the homemade stuff and come ready to grow out of the bag.
At face value, super soil sounds pretty simple, but it is as much a method as it is a medium. While promises of not having to follow a regular feeding schedule can sound attractive to many growers, especially beginners, using standard fertilizing methods for organic indoor gardening is actually a bit easier. The main allure of the method is the ability to create high-quality yields using only organic inputs that are controlled by the grower. But what you gain in control over the input, you give up in terms of feeding precision. Super soil won’t necessarily deliver bigger yields, but it is a great technique for producing outstanding product quality and saving money in the long run if you mix your own. If you’re ready to give super soil a shot, stop by your local HTG Supply or give us a call, and we’ll be happy to help you get started!
Questions, tips, or tricks to share? Join the conversation, and tell us your super soil story! Throw a picture on Instagram and tag us in it (@HTGSupply) – we'd love to see your results! And don't forget to check out this week’s coupon code and sale information below! From all of us here, good luck, stay safe, and Happy Growing!
THIS WEEK'S COUPON CODE: SUPERSOIL
Enter this week's promo code at checkout for a 10% discount on the products featured below or visit your local store and simply mention this article to get the deal! Thanks again for tuning into Talking Shop with HTG Supply! Offer valid through HTGSupply.com and in-store 12/29/17-01/05/17. Cannot be combined with other offers. Follow us on social media for all the Sales, Events and Customer Appreciation Days. In addition, learn more about indoor growing and get all kinds of tips, tricks and techniques!