I've noticed instant results and improvements in all areas of my garden since adopting the HPO methodology
The girls LOVE this product and great at all stages.
GRO-DIRT Super Starter – Organic Living Soil
GRO-DIRT Super Starter is a premium organic raising blend engineered for explosive root growth and early vigor in seeds and clones. Developed through extensive testing, it combines a finely tuned aerated base with biodynamic compost, vermicast, humic-rich biochar, and high paramagnetic basalt, creating an ideal environment for stable temperature, moisture retention, and early microbial colonization. Inoculated with endo/ecto mycorrhizae, Trichoderma, and root-stimulating microbes, it delivers a biologically active foundation without synthetic fertilizers—just water required. Perfect for propagation trays, seedling pots, or direct sowing, it supports a seamless start and primes young plants for high-performance growth.
GRO-DIRT Super Starter – Organic Living Soil
Sale price$16.50 AUD
Where biology, minerals, and science collide.
Explore the Edge of Organic Innovation & Cultivation
GRO-DIRT
SUPER STARTER
GRO-DIRT Super Starter is a premium, organic propagation blend designed to deliver explosive root development and early-stage vigor in seeds and clones. Developed through rigorous testing, it features a finely balanced base of aerated peat, coco coir, perlite, volcanic ore, diatomite, and fine biochar—perfectly tuned for moisture retention, drainage, and stable root zone temperature. The inclusion of biodynamic bovine compost and VermI-PowR vermicast supplies gentle, microbe-rich nutrition. Inoculated with Trichoderma, endo/ecto mycorrhizae, and nitrogen-fixing soil probiotics, it provides a living soil foundation from day one. This is a water-only mix—no boosters or amendments required—and supports optimal health, branching, and vigor in even the most sensitive cultivars. Perfect for seedling trays, clone pots, or direct sowing.
Organic Doesn’t Mean Underpowered
We reject the outdated notion that organic cultivation is slow, weak, or imprecise. Our living soils are not just rich in nutrients — they’re engineered ecosystems, biologically primed to deliver consistent, high-performance results across any growing style. While conventional soils often rely on synthetic inputs or sterile blends, GRO-DIRT leverages advanced composting, high-density microbial consortia, and carefully balanced mineral ratios to drive nutrient cycling, hormonal signaling, and root-zone synergy. This means faster establishment, denser growth, and higher-quality yields — all without the burn or crash cycles seen with chemical programs.
Is GRO-DIRT Super Starter the right soil for you?
If you’re starting seeds, rooting clones, or growing in very small containers, GRO-DIRT Super Starter is built for the job. This blend is precision-optimized for young plants, offering a smoother, finer texture that supports delicate root systems while balancing moisture and airflow. It contains all the upgraded biology and inputs of the GRO-DIRT range, but with an ultra-refined matrix that outperforms traditional seed raising mixes. Super Starter holds enough nutrition to carry your plants through their early stages with just water — no need to rush in with extras. It’s clean, consistent, and built to deliver strong starts every time.
Best for: Seed raising, clone trays, propagation domes, small pots, and water-only starts in high-performance systems.
The Science Behind GRO-DIRT
At the core of GRO-DIRT’s performance is not just what goes into it — but how it’s made. This isn’t your average soil mix. Every step, from fermentation to microbial inoculation to structural engineering, is guided by rigorous process control, scientific precision, and biological insight. Below, we unpack the key technologies and methods that make GRO-DIRT a category-defining living soil — purpose-built for serious growers who demand more from their media.
GRO-DIRT is fortified with over 15 unique fermented inputs — including horsetail (Equisetum), dandelion, comfrey, alfalfa, Kelp, hops, and ocean minerals (Sea-90). These aren’t raw plant powders or basic KNF — they’re processed in controlled microbial fermentations, in specialised temperature-controlled custom reactors using our own EM1 cultures. The result: living metabolites, enzymes, trace minerals, and plant signalers that boost growth and resilience from the root zone up.
We've significantly upgraded the way we do our IMO collections. We selectively cultured high-performing IMO lineages and scaled them under controlled conditions — locking in the best traits. Each GRO-DIRT batch is now inoculated with this custom IMO derivative, along with live in-house-grown mycorrhizal fungi and freshly fermented EM1, aerobic microbe teas along with a suite of other beneficial micoorganisms and rhizobacteria — ensuring a thriving, competitive microbiome from day one.
The trouble with trying to make a really nutritionally dense soil that can perform well on Water-Only is that all the ingredients that hold a lot of horsepower - also hold a lot of moisture (Compost, Castings, Amendments, minerals), this presents a challenge as a nutritionally dense, yet very low O2 blend means slow growth. GRO-DIRT Full Spectrum Blend uses a very carefully put together drainage profile containing multiple, Long lasting raw-ores (Like Scoria and Pumice), along with multiple Perlite grades and 3–6mm granulated cork bark — a sustainable, ultra-light, porous material that maintains ideal aeration, insulation, and microbial colonization without waterlogging or compaction. This allows us to maintain high nutrient density without compromising structure.
A premium blend of pecan shell and macadamia nut shell biochar, inoculated with fresh microbes and special protein sources, pre-activated for each batch. Presents a great contrast to most “sticks and twigs” biochar on the market, made from “tree trimmings” and unknown phytotoxicity levels. Nut shell char is sustainable, non-phytotoxic, premium, and of a consistent sizing. Pecan, we find, crumbles up and evenly distributes through the mix, with the macadamia nut acting as semi “microbe orbs” that trap ingredients and moisture, and provide a place for beneficial organisms to live and grow outward from—lasting longer term.
Each GRO-DIRT batch is made indoors using clean, custom equipment, made only to make GRO-DIRT — no tractors, bobcats and rough treatment. Amendments are hand-measured to the gram per batch (not in bulk), and each stage of the mix is portioned to within exceedingly slim margins. Multi-stage composting and curing is carried out in sealed batch bags for 6+weeks, indoors before bagging. The result: an ultra-consistent, ready to use, peak-performance soil — every time.
No Mixing. No Measuring. Just Growing.
How to Use GRO-DIRT
Simply open the bag, lightly fluff, and plant directly. GRO-DIRT is water-only from cut to harvest in most scenarios, as long as a large enough container is used. For maximum performance—and when using smaller container sizes—it can be boosted with our CROP-DRESSINGS: HERB-SUPERB & STONE-AGE, our POWR-BOOSTER soluble fertilisers: AQUA-MARINE, OCEAN-POTION, and GREEN-SUPREME, as well as our GRO-BIOTICS: RHIZO-MOJO, ANTI-MATTER, and DARK-MATTER.
Recommended Plant Pot Size for Optimal Growth: 50L Per Plant
Dial in your grow with our Dynamic Feed Chart & Soil Volume Calculator
Need to reammend your GRO-DIRT? Watch our video guide HERE.
Frequently Asked Questions
What is GRO-DIRT Super Starter used for?
It’s a premium organic soil for seeds, seedlings, and clones. Designed for explosive early root growth and vigor, it requires only water—no added fertilisers or boosters.
How is it different from GRO-DIRT Full Spectrum or GRO-DIRT Lite?
GRO-DIRT Super Starter is optimized for germination and rooting, with gentler nutrients, finer texture, and superior temperature control—perfect for propagation trays and early veg development.
Can I plant seeds directly into GRO-DIRT Super Starter?
Yes. Direct sowing is ideal. It gives emerging roots immediate access to nutrients, microbes, and insulation—avoiding transplant shock and boosting early performance, especially in autos.
What makes this better than paper towel germination?
Paper towels offer no nutrition or protection. GRO-DIRT Super Starter provides a buffered, living environment with microbes, minerals, and moisture stability—supporting healthy root formation from day one.
Does GRO-DIRT Super Starter work with heat mats or cables?
Absolutely. It’s been tested for even heat distribution and insulation, reducing hot spots and helping roots stay warm, stable, and active during early development.
What microbes and minerals are included?
It contains nitrogen-fixers, phosphorus-solubilizers, mycorrhizae, Trichoderma, high-paramagnetic basalt, and Azomite—all supporting early growth, resilience, and long-term plant health from the very first root contact.