Will I have bugs flying around my house?

No. They stay on the plants, where their food is.

Can I use Root Biome Builder in semi-hydroponics (LECA or Pon)?

Yes. While designed for soil-based containers, the Bacillus strains in Root Biome Builder work in inorganic media like LECA or Pon too, where there is otherwise very little biology around the roots. Keep rinsing the reservoir as usual.

Will this product cause a biofilm or "slime" in my self-watering pots?

When used at the recommended dilution, Root Biome Builder promotes a healthy microbial balance. However, because it contains live cultures, we recommend rinsing your reservoirs every 4–6 weeks to prevent any natural organic buildup, especially if using organic-based fertilizers alongside it.

Is Root Biome Builder safe for propagation and "rehab" plants?

Yes. Propagation is one of the best times to use it. Introducing beneficial bacteria early in the rooting process—whether in moss, perlite, or water—gets them onto the new roots from the start, before the move to a permanent potting mix.

Can I use this alongside my regular liquid fertilizers?

Yes, it is compatible with most synthetic and organic fertilizers. For the best results, mix your nutrients first and add Root Biome Builder last. Avoid mixing it with concentrated "flush" products or high-strength peroxide treatments, as these are designed to sterilize the environment.

How soon will I see results in my aroids?

The bacteria go to work at the roots straight away, but any visible difference (such as steadier growth through a repot) tends to show after 2–3 applications rather than the first. The goal is to build long-term "rhizosphere resilience" rather than a temporary chemical spike.

Does this product have a strong odor?

Root Biome Builder is a clean, liquid formulation with a very mild, earthy scent that is virtually unnoticeable once diluted. Unlike some fish-based or heavy organic fertilizers, it is perfectly suited for use on indoor shelving and in living spaces.

How much Root Biome Builder do I need?

Work it out from the gallons of drench you will pour, not the bottle size. The rate is 4–8 mL per gallon of water (1–2 mL per liter), enough to saturate the medium evenly. Measure: how many gallons it takes to saturate every pot you are treating, then multiply by the number of drenches you plan (every three to four weeks in active growth, plus one after any repot). At the full 8 mL per gallon: an 8 oz bottle makes about 30 gallons of drench, 12 oz about 44, 16 oz about 59, and 32 oz about 118. At 4 mL per gallon: each bottle goes twice as far. There is no pest count to size for, so there's no sizing up or down for pressure. A bottle is not one application: it covers repeated drenches, so pick the size that matches a few months of watering.

Root Biome Builder

Name: Root Biome Builder
Brand: FGMN Nursery
SKU: ROOT-8OZ
Price: 80.00 USD
Availability: InStock

Bacillus subtilis and Bacillus amyloliquefaciens5.01 review

$80per bottle

New potting mix is a fresh start. This fills in what's missing.

Fresh potting mix starts sterile. Root Biome Builder adds the root bacteria natural soil already has.

Ships live, when readyUsually within 7 days, rarely 10. Mon–Thu, 2-day or overnight.
Free shippingWhen bugs and plant care come to $30

Pairs well with

Rust & Orange Watercolor Planter

Handmade by Linda, for the plants you're protecting

2 inch · $20

Buying for a group or a business? · Wholesale

01 · The problem

Is Root Biome Builder right for your pots?

When it fits best

Potting and repotting, when new roots grow into bare mix
Deflasked tissue culture hardening off with no root life yet
Inert media: coco, rockwool, perlite, LECA and semi-hydro
Long-term pots that have sat in the same container for years

Illustration · not to scale

Illustration · not to scale

You receive: A bottled liquid culture of two beneficial Bacillus bacteria
Main target: Root zones starting empty: fresh mix, coco, rockwool, perlite, LECA
How much: 4–8 mL per gallon of water (1–2 mL per liter)
How to use: Shake, dilute, drench; every 3–4 weeks in active growth
Storage: Sealed, 35–77°F, out of direct sun; never frozen
Not for: Killing pests or pathogens, or rescuing a rotting plant

Works on

Microbial diversity
Nutrient availability
Steady root-zone biology
Root resilience

Not the answer for

Killing pathogens or insects
Rescuing a plant that's already rotting
Feeding the plant: it isn't fertilizer

02 · Meet the product

Root Biome Builder

Natto's cousin. Same species, different job.

Natto, the Japanese fermented soybean dish, is made with a type of this same bacterium. Same species, different job.

Roots send the invitation
Roots give off sugars that tell this helpful bacterium to settle in and build a thin, slimy coating on them. It even uses those sugars as building material.
Built to wait
When food runs short, it can turn into a tough, sleeping form, a bit like a seed, and wait until conditions improve.
A name that tells the story
The other bacterium's name, amyloliquefaciens, means starch-melter. It's named for what it does: turning starch to liquid.

03 · How it works

Living helpers for the root zone

Illustration · not to scale
Mix and drench
Dilute and water it in at the base.
Illustration · not to scale
They settle on the roots
Beneficial microbes take up space and work with the plant from the start.
Illustration · not to scale
Safe alongside your beneficials
They work below the soil line while predators work above.

Root Biome Builder storage

Illustration · not to scale
35–77°FStore it tightly sealed, out of direct sunlight.
Illustration · not to scale
Never frozenFreezing and long spells of heat shorten its life.
Illustration · not to scale
Semi-hydroRinse self-watering reservoirs every 4–6 weeks so organic matter doesn't build up.

04 · Not your conditions?

Choose one of these instead

Not quite your situation? No problem. If your space or your pest is different, one of these fits better.

Root rot is the worryTrichoderma harzianum

T-22 is the one built to guard roots against rot

View →

You want the whole root crew at repottingRoot Network: Mycorrhizae + Microbial Inoculant

Mycorrhizae, a Trichoderma and root bacteria in one pouch

View →

Fungus gnats or thrips pupae in the mixStratiolaelaps scimitus

A soil-dwelling mite that hunts them in the top inch

View →

05 · The plan

How to use Root Biome Builder

No experience needed. Here's all it takes.

Illustration · not to scale
Shake gently
It's a live culture and it settles in the bottle.
Illustration · not to scale
Dilute
4–8 mL per gallon of water, or 1–2 mL per liter. Mixing fertilizer too? Add this last.
Illustration · not to scale
Drench at the base
Pour until the medium is evenly saturated, not just the surface.
Illustration · not to scale
Repeat
Every 3–4 weeks in active growth, and straight after any repot.

06 · What happens next

What to expect

Here's what normal looks like.

Illustration · not to scale

Illustration · not to scale

Bacteria on the roots
They settle in the root zone and support the breakdown and availability of nutrients already there.
Two or three goes
A colony has to establish first, so any difference tends to show after two or three applications.
Roots that settle in
Look for a plant that roots into new mix confidently and holds steady through a repot or a deflask.
Not a rescue
It won't bring back rotted roots and doesn't attack what caused them. For root rot, T-22 is the one.

How many do I need?

How much Root Biome Builder to buy

Each gallon of drench takes 4–8 mL; the counts below assume the stronger rate. Plan a drench every 3–4 weeks in active growth, plus one after each repot.

A few houseplants, up to 30 gallons of drench	8 oz bottle
A big collection or a tent, up to 60 gallons	16 oz bottle
A greenhouse or grow room, up to 120 gallons	32 oz bottle

07 · Reviews

What growers say

Before you order

All your questions, answered

Something else? Toby's in the chat, bottom right, and happy to help.

When does it ship, and how does it arrive?

A bottled liquid concentrate that ships as ordinary goods, with nothing urgent on arrival. Store it sealed and it's ready when you are. Bugs and plant care ship free from $30; $15 under that. Pots and grow lights ship by ground, free from $75.

Can I use it with my fertilizer?

Yes, with most synthetic and organic fertilizers. Mix your nutrients first and add this last. Keep it away from flush products, high-strength peroxide and disinfectants.

Is it good for propagation?

Yes, it's one of the best times. Adding it early, in moss, perlite or water, gets the bacteria onto new roots from the start.

Does it smell?

A very mild, earthy scent that's barely noticeable once diluted, so it suits indoor shelves and living spaces.

Can you ship it to my state?

It's approved for sale in AL, AR, AZ, CA, CO, CT, DC, DE, FL, GA, ID, IA, IL, IN, KY, LA, ME, MA, MD, MI, MN, MO, MS, MT, NJ, NY, NC, ND, NV, OH, OR, PA, RI, SC, TN, TX, UT, VA, WA, WV and WI. Elsewhere, email us before ordering.

Ready when you are

Root Biome Builder

You've got this. And if you get stuck, we're one email away at info@fgmnnursery.com.

Change size or plan ↑

From Field Notes

Your Roots Recruit Bacteria→Your Roots Have Company→Finding the Roots Worth Saving→

Root Biome Builder

Size. Pick a package.

Add to cart.

Is Root Biome Builder right for your pots?

When it fits best

Works on

Not the answer for

Root Biome Builder

Roots send the invitation

Built to wait

A name that tells the story

Living helpers for the root zone

Mix and drench

They settle on the roots

Safe alongside your beneficials

Choose one of these instead

How to use Root Biome Builder

Shake gently

Dilute

Drench at the base

Repeat

What to expect

Bacteria on the roots

Two or three goes

Roots that settle in

Not a rescue

How much Root Biome Builder to buy

What growers say

All your questions, answered

Root Biome Builder

Hi! I’m Toby, your AI assistant