Product
UNDER SOD™
The 4-2-5, iron-free biological granular starter fertilizer built for the soil-to-root zone beneath new turf.
Specifications
Product Spec Sheet
| N-P-K Ratio | 4-2-5 (K-forward, moderate phosphorus) |
|---|---|
| Iron | None — iron-free by design |
| Endomycorrhizae | Four turf-specific endo species (Rhizophagus irregularis, Funneliformis mosseae, Glomus aggregatum, Glomus etunicatum) |
| Beneficial Bacteria | Bacillus PGPR consortium (B. amyloliquefaciens, B. megaterium, B. subtilis) |
| Trichoderma | T. harzianum / T. virens |
| Microbial Food | Carbohydrate / amino-acid carbon source |
| Seaweed Extract | 2% (Ascophyllum nodosum) |
| Humic Acid | 6% (leonardite-derived) |
| Fulvic Acid | Included (bioavailable carbon + chelator) |
| Granule Size | SGN 90 (fine) |
| Net Weight | 25 lb per bag |
| Coverage | 500 sq ft — one pallet of sod per bag |
| Application Timing | Pre-installation, directly beneath new sod |
| Grass Types | All cool-season turfgrasses (KBG, tall fescue, RTF, ryegrass, fine fescues) |
| Availability | Fall 2026 — Northeast U.S. via the CT Sod network |
The Formula
One Rooting Strategy, Engineered Input by Input
Every component is included to do one job: help freshly cut sod rebuild roots fast and establish into a healthier, more self-sufficient lawn.
4-2-5
K-Forward NPK Base
Moderate, mostly slow-release nitrogen with deliberately low 2% phosphorus (to stay mycorrhizae-compatible) and elevated 5% potassium that drives drought, cold, and transplant-stress tolerance — feeding new roots without burning them or forcing top growth.
AMF
Named Endomycorrhizae
Four turf-specific endomycorrhizal species — Rhizophagus irregularis, Funneliformis mosseae, Glomus aggregatum, and Glomus etunicatum — colonize freshly cut roots and extend their reach through microscopic filaments, increasing water and nutrient uptake during establishment.
PGPR
Bacillus Consortium
A plant-growth-promoting Bacillus consortium — B. amyloliquefaciens, B. megaterium (phosphate-solubilizing), and B. subtilis (root colonization) — works the root zone to cycle nutrients and support recovery, fed by an included carbohydrate and amino-acid carbon source.
Live
Trichoderma
Trichoderma harzianum and Trichoderma virens colonize the developing root zone and lend establishment-phase support as the severed roots rebuild in unfamiliar soil.
2%
Seaweed Extract
Cold-water brown algae (Ascophyllum nodosum) delivers natural cytokinins and auxins that reduce transplant shock and trigger root initiation.
6%
Humic + Fulvic Acids
Leonardite-derived humates build cation exchange capacity and chelate micronutrients, while added fulvic acid — a smaller, highly bioavailable carbon molecule — shuttles nutrients straight into the root zone and feeds the soil biology.
Iron-free by design.
We root the sod. We don't green the bag. UNDER SOD™ contains no iron — a quick cosmetic color-up is something you can always add later, but rooting is the one decision that can't be redone once the sod is laid.
25 lb
Per bag
Granular SGN 90 formula in a single, ready-to-spread bag.
500 sq ft
One pallet of sod, one bag
No measuring, no math, no rate calculations. One bag covers one pallet.
Compatibility
Grass Types UNDER SOD™ Can Be Used With
UNDER SOD™ is built around the sod installation itself, so it works the same way across cool-season and warm-season sod.
Cool-Season Sod
- Kentucky bluegrass
- Tall fescue
- Bluegrass / fescue blends
- Perennial ryegrass blends
Ideal for Northeast, Midwest, transition zone, and other cool-season sod markets where root establishment and stress recovery are critical after installation.
Warm-Season Sod
- Bermudagrass
- Zoysiagrass
- St. Augustinegrass
- Bahiagrass
- Centipedegrass*
Built for the same establishment goal warm-season sod needs: stronger rooting, better soil contact, and reduced installation stress during active growing conditions.
*For centipedegrass and other low-input warm-season grasses, apply according to soil test recommendations or local fertilizer guidelines.
Availability
UNDER SOD™ launches Fall 2026.
Rolling out across the Northeast first through CT Sod's network (CT, MA, NY, NJ, RI, NH, VT, ME, PA) and select regional partners. Join the list to know the moment it's available in your area.
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