PRODUCT 04 · THE SPEED PLAY

Silica Root Zone

Name: Silica Root Zone
Brand: Silica Earth
Price: 37.95 USD
Availability: InStock

Immediately plant-available silica for the root zone — and it frees up phosphorus your soil is already holding but your plants can't reach. For growers who want to see a change this month, not next season.

Immediately plant-available silica for the root zone — and it frees up the phosphorus your soil is already holding.

4.8 61 grower reviews

$37.95

$44.95

SAVE 16%

1 · CHOOSE YOUR SIZE

2 · HOW OFTEN

1

Title

Free shipping over $75

In by 2pm PT ships today

30-day guarantee — CONFIRM

Free shipping over $75 · flat $8.95 under

Orders in by 2pm PT ship the same business day

30-day grow-it-and-see guarantee — CLIENT TO CONFIRM

Milled and bagged on our own farm in Northern California

OMRI LISTED

CDFA ORGANIC INPUT

pH-NEUTRAL · NO CAUSTIC SILICATES

OMRI LISTED

CDFA ORGANIC INPUT

pH-NEUTRAL

OMRI
LISTED

CDFA ORGANIC INPUT

pH-NEUTRAL · NO
CAUSTIC SILICATES

WHY THERE ISN'T ALWAYS A PALLET OF IT

Small batch, because that's the only way to make it properly.

Root Zone is the hardest bag we make. The fraction that dissolves fast enough to matter in days — not months — is a small slice of what comes off the mill, and we won't blend in cheap filler to stretch a batch. What that means in practice is that we mill it in runs, each run is finite, and when a run is claimed we wait for the next one rather than ship something thinner.

Root Zone is the hardest bag we make. The fraction that dissolves fast enough to matter in days — not months — is a small slice of what comes off the mill, and we won't blend in cheap filler to stretch a batch. So we mill it in finite runs, and when a run is claimed we wait for the next one rather than ship something thinner.

Batch 24-B came off the mill this month. No fake countdown on this page — the number beside the cart is the real one.

Batch 24-B came off the mill this month. It's on the shelf now and it moves fast in season — last spring's run went in nineteen days. There's no fake countdown on this page; the number beside the cart is the real one, and when it reaches zero the button changes to a waitlist until the next run is bagged.

If you're deciding between this and the season-long bag, we'd rather help you get it right than sell you the wrong one — the four-product comparison is here, and a grower on our team will tell you honestly if Root Zone isn't what your plants need.

Title

24-B

CURRENT BATCH

19

DAYS THE LAST RUN LASTED

2–4 μm

MILLED PARTICLE SIZE

THE PROBLEM

You already bought the phosphorus. Your soil is just holding it hostage.

You already bought the phosphorus. Your soil is holding it hostage.

Most growers respond to a slow, sulky plant by feeding it more. But in the majority of soils, a large share of the phosphorus you've already applied is bound up — locked to iron, aluminium and calcium where roots can't reach it. You keep paying for a nutrient that never arrives. Meanwhile the plant's own structural defence, silicon, has been mined out of over-cropped and container soils, and almost nothing you buy puts it back.

Most growers respond to a slow, sulky plant by feeding it more. But in the majority of soils, a large share of the phosphorus you've already applied is bound up — locked to iron, aluminium and calcium where roots can't reach it.

You keep paying for a nutrient that never arrives. Meanwhile the plant's own structural defence, silicon, has been mined out of over-cropped and container soils, and almost nothing you buy puts it back.

In most soils a large share of the phosphorus you've applied is locked to iron, aluminium and calcium where roots can't reach it — so you keep paying for a nutrient that never arrives. Meanwhile silicon, the plant's own structural defence, has been mined out of over-cropped and container soils.

Feeding more, getting less

Purple stems and stalled transplants often mean a nutrient that's present and unavailable. More of it just adds more locked phosphorus.

Purple stems, stalled transplants and a slow start aren't always a missing nutrient — often it's a nutrient that's present and unavailable. Adding more of it mostly adds more locked phosphorus.

Soft tissue, no armor

Silicon is what stiffens cell walls. Without it, plants stay soft — easier for mildew to enter, easier for heat to wilt, easier for a heavy branch to snap in the last three weeks before harvest.

Silicon stiffens cell walls. Without it, mildew enters easier, heat wilts faster, and heavy branches snap in the last weeks before harvest.

And it's already mid-season

Season-long amendments assume you started in spring. When you're already deep into the year and something's wrong, you need a mineral that's available now — not one that mineralises over four months.

Season-long amendments assume you started in spring. Mid-season you need a mineral that's available now, not one that mineralises over four months.

HOW IT WORKS

Two jobs, one scoop, starting the day you water it in.

Root Zone is the same volcanic mineral as the rest of the range, milled and formulated so that a meaningful fraction goes into solution as monosilicic acid almost immediately, right where the fine roots are working. Two things follow from that.

STEP 01

It dissolves where roots can drink it

Micronised mineral releases plant-available silicon into the soil solution right at the root zone. Uptake begins with the next irrigation, not next month.

Watered in, the micronised mineral releases plant-available silicon into the soil solution in the root zone rather than sitting in the profile waiting to weather. Uptake begins with the next irrigation, not the next month.

STEP 02

Silicate ions displace bound phosphate

They compete for the same binding sites. As silicate takes them, phosphorus locked to iron and aluminium is released back into solution.

Silicate and phosphate compete for the same binding sites on soil particles. As silicate occupies them, phosphorus that was locked to iron and aluminium is released back into solution — nutrition you already paid for, returned to the plant.

STEP 03

The plant builds itself armor

Silicon deposits in cell walls and under the leaf surface. Stems stiffen and the plant gets physically harder for mildew, mites and heat to damage.

Absorbed silicon deposits in cell walls and under the leaf surface. Stems stiffen, leaves stand up, and the plant becomes physically harder for mildew, mites and heat to damage. This part compounds week over week.

PARTICLE SIZE IS THE WHOLE ARGUMENT

SAND

100 μm

SILT

10 μm

ROOT ZONE

SILICA ROOT ZONE

2–4 μm

A mineral only feeds a plant at the surface where it meets water. Grinding the same rock from silt-size down to 2–4 microns multiplies that surface area enormously — which is why a dry powder can act faster than a bottle of liquid, and why cheap "silica sand" or diatomaceous earth does almost nothing on a season timescale. It isn't a different rock. It's the same rock, ground until it's actually usable.

WHAT YOU'RE COMPARING IT TO

VS THE BOTTLE

The bottle looks cheaper until you do the arithmetic.

A quart of potassium silicate is fifteen dollars and mostly water, at a pH somewhere near household ammonia, and you re-buy it every few weeks. Here's the honest side-by-side — including the places where the bottle still wins.

.

ROOT ZONE

LIQUID

Time to available

Days

Then gone

pH of concentrate

Neutral

10–12

Frees phosphorus

Yes

Minimal

Cost per application

≈ $1.58

≈ $2.10

Bottle still wins at

Needs stirring

No mixing

COMPETITOR PRICING AND COST-PER-APPLICATION ARE ESTIMATES — CONFIRM AGAINST CURRENT LABEL RATES AND RETAIL PRICES BEFORE LAUNCH

.

SILICA EARTH (DRY MINERAL)

LIQUID K-SILICATE BOTTLE

SILICA SAND / DE

Time to plant-available

Days

Immediate, then gone

Years

pH of the concentrate

Near neutral

10–12 · caustic

Neutral

Frees bound phosphorus

Yes

Minimal

No

Cost per application

≈ $1.58

≈ $2.10, re-bought

Pennies, no effect

Shipping water you don't need

None

~90% of the bottle

None

Where the bottle still wins

Needs stirring in solution

Pre-dissolved, zero mixing

Cheapest per pound

COMPETITOR PRICING AND COST-PER-APPLICATION ARE ESTIMATES

HOW TO USE IT

Three ways in, and none of them need a chemistry set.

Three ways in, none needing a chemistry set.

Root Zone is designed to go in through water. Shake or stir it into suspension, apply, and keep the line moving — at 2–4 microns it stays suspended long enough for a watering can, a backpack sprayer or a fertigation run without settling into a paste at the bottom.

METHOD A · SOIL DRENCH

Water it in at the base

1 tsp per gallon, stirred, poured at the base. Fastest route in, and the one to use if something's already going wrong.

1 tsp per gallon, stirred, poured at the base of the plant. The fastest route in, and the one to use if something is already going wrong.

METHOD B · FOLIAR

Spray it onto the leaves

½ tsp per gallon, morning or evening, both surfaces to run-off. Best under pest and mildew pressure.

½ tsp per gallon, early morning or evening, both leaf surfaces to run-off. Best under pest and mildew pressure — the armor forms where it lands.

METHOD C · FERTIGATION

Run it through the drip

Pre-suspend in an agitated tank and inject as normal. In use on commercial drip and pivot without filter issues.

Pre-suspend in a mixing tank with agitation and inject as normal. In use on commercial drip and centre-pivot systems without filter issues.

RATES · CONFIRM AGAINST LABEL

Transplant

½ tsp/gal · every 2 wks

Under stress

1 tsp/gal · every 10–14 d

Established

1 tsp/gal + foliar · weekly ×3

Commercial

2–4 lb/acre · per event

APPLICATION RATES · CONFIRM AGAINST THE PRINTED LABEL BEFORE PUBLISHING

SITUATION

RATE

FREQUENCY

NOTES

Transplant / seedlings

½ tsp / gal

At planting, then every 2 weeks

Reduces transplant shock

Established plants

1 tsp / gal

Every 10–14 days

The standard maintenance rate

Heat, pest or mildew pressure

1 tsp / gal + foliar

Weekly for 3 weeks

Then back to maintenance

Commercial fertigation

2–4 lb / acre

Per irrigation event

Agitated tank; ask us for a plan

WHAT TO ACTUALLY EXPECT

WHAT TO EXPECT

Fast, for a mineral.
Not magic, on any timescale.

Fast, for a mineral. Not magic, on any timescale.

The biggest benefits are ones you notice by their absence — the mildew that didn't take, the branch that didn't snap. The honest curve:

"Fast-acting" in soil terms means days, not hours, and the biggest benefits are the ones you notice by their absence — the mildew that didn't take hold, the branch that didn't snap. Here is the honest curve, so nobody is disappointed in week one.

Title

DAYS 1–5

Turgor and colour

Leaves hold themselves up better through the afternoon; growers often describe plants "looking awake" at 3pm. Subtle, and easy to talk yourself out of.

Title

WEEK 2–3

New growth comes in harder

The tissue formed since you started is the tissue with silicon in it. Stems feel stiffer between finger and thumb; leaf edges are less ragged.

Title

WEEK 4–6

Stress days stop costing you

The heat wave that used to stall growth for a week costs you a day or two. Pest and mildew pressure meets a physically tougher plant.

Title

HARVEST

Weight held up, not lost

Fruit and flower that stayed on the plant instead of going down to rot or breakage. The gain is mostly in what you didn't lose.

DAYS 1–5

Turgor and colour

Leaves hold up better through the afternoon. Subtle, and easy to talk yourself out of.

WEEK 2–3

New growth comes in harder

Tissue formed since you started is the tissue with silicon in it. Stems feel stiffer.

WEEK 4–6

Stress days stop costing you

A heat wave that stalled growth for a week costs you a day or two instead.

HARVEST

Weight held up, not lost

The gain is mostly in what you didn't lose to rot or breakage.

DON'T BUY THIS IF

Three reasons to close this tab.

We'd rather lose the sale than take money from a grower it won't help. If any of these are you, buy something else — including something that isn't ours.

You're looking for a fertiliser

This isn't NPK and won't replace your feed. A hungry plant needs food first — then this.

This is not NPK and it will not replace your feed. It makes what you're already feeding work harder and makes the plant tougher. A hungry plant needs food first — then this.

Your plants are three days from harvest

You're three days from harvest

Silicon builds into new tissue. At the very end of a cycle there's almost nothing left to build into.

Silicon builds into new tissue. Applied at the very end of a cycle it has almost nothing left to build into. Start at transplant, or at minimum four to six weeks out.

You want one bag to do everything

Root Zone is the targeted option. If you'd rather buy once and not think, the Bio-Activator is the better bag.

Root Zone is the targeted, fast option. If you'd rather buy once and not think about it, the Bio-Activator is the better bag and we'll happily point you there.

GROWER PROOF

What growers who used it actually said.

4.8

/ 5 · 61 REVIEWS

5

51

4

7

3

2

1

0

THE ONE-STAR RULE

We publish every review, including the bad ones. If a grower says it did nothing for them, you'll read it here rather than find it on Reddit.

"Watered it in on a Sunday and by the next weekend the tomatoes were standing up in the afternoon instead of flopping. First silica product where I could point at the change."

PLACEHOLDER QUOTE · MARKET GARDEN, OREGON · VERIFIED BUYER

"Watered it in on a Sunday and by the next weekend the tomatoes were standing up in the afternoon instead of flopping."

PLACEHOLDER · MARKET GARDEN, OREGON

HEMP STARTS · SALEM, OR

"I'd sworn off silica after a potassium silicate product wrecked my reservoir pH. This one didn't move my pH at all."

PLACEHOLDER · INDOOR GROWER, MICHIGAN

HEMP STARTS · SALEM, OR

"I'd sworn off silica after a potassium silicate product wrecked my reservoir pH. This one didn't move my pH at all, which is the only reason I kept using it."

PLACEHOLDER QUOTE · INDOOR GROWER, MICHIGAN · VERIFIED BUYER

"Four stars because I couldn't tell much in the first two weeks and nearly gave up. By week five the stem thickness was obvious."

PLACEHOLDER · HOME GARDENER, NORTH CAROLINA

"Four stars because I couldn't tell much in the first two weeks and nearly gave up. By week five the difference in stem thickness was obvious. Wish the label said that plainly."

PLACEHOLDER QUOTE · HOME GARDENER, NORTH CAROLINA · VERIFIED BUYER

SAME ROW · SAME WEEK · SIDE BY SIDE

SAME ROW · SAME WEEK

IF NOT THIS ONE

Four bags. Root Zone is the fast one.

Four bags. Root Zone is the fast one — here's the rest.

All four are the same volcanic mineral at the core. What changes is what we put with it and how quickly it goes to work. Pick by how you grow, not by price.

MOST GROWERS START HERE

Volcanic Silica Minerals

The foundation bag. Same mineral, season-long release. Runs underneath everything else in the range.

The foundation bag, season-long release.

FOR LIVING SOIL

Silica + Beneficial Microbes

Adds four Bacillus and four mycorrhizal species. The pick for no-till beds and anyone brewing compost teas.

Adds Bacillus and mycorrhizae. For living soil.

ALL-IN-ONE

Silica Soil Bio-Activator

Silica plus humic and fulvic acids plus kelp. One scoop, armor and feeding together, no decisions to make.

Silica plus humics, fulvics and kelp. All-in-one.

YOU ARE HERE

Silica Root Zone

The speed play. Immediate plant-available silica plus phosphorus release, for growers who need a change now.

The speed play. Fast silica plus phosphorus release.

THE PAIR MOST GROWERS END UP WITH

THE USUAL PAIR

Fast now, covered for the rest of the season.

Fast now, and covered for the rest of the season.

Root Zone solves the immediate problem; the Minerals bag keeps supply steady so it doesn't come back. Two in three Root Zone buyers come back for it anyway — this skips the second shipping charge.

Root Zone solves the immediate problem; Volcanic Silica Minerals keeps the supply steady from transplant to harvest so the problem doesn't come back. Bought together they cover the whole curve — the fast release and the slow one — and the pair ships in a single box, which is most of why it costs less.

Roughly two in three growers who buy Root Zone come back for the Minerals bag within a season. This just skips the second shipping charge.

BUNDLE · SAVE $17.95

Root Zone 2 lb + Volcanic Silica Minerals 2 lbRoot Zone 2 lb + Minerals 2 lb

SHIPS AS ONE BOX

$69.95

Regular price $87.90

BUNDLE PRICING IS A PLACEHOLDER — CONFIRM MARGIN BEFORE LAUNCH

WHAT'S IN THE BAG

One ingredient, and the paperwork to back it.

Volcanic mineral, mined and milled, and nothing else — no carriers, no anti-caking agents, no dye. It's listed by OMRI and registered as a CDFA Organic Input Material, which means certified organic growers can use it without a phone call to their inspector.

Heavy-metals screening is run on every production batch. If you want the certificate of analysis for the batch you received, email us the lot number on the bag and we'll send the PDF.

Volcanic mineral, mined and milled, nothing else — no carriers, no anti-caking agents, no dye. OMRI listed and CDFA registered, with heavy-metals screening on every batch. Email us a lot number and we'll send the COA.

OMRI LISTED

CDFA OIM

BATCH COA ON REQUEST

SPECIFICATION

SPECIFICATION · CONFIRM AGAINST LABEL

SOURCE

VOLCANIC MINERAL

VOLCANIC MINERAL DEPOSIT

PARTICLE SIZE

2–4 MICRONS

FORM

DRY MICRONISED POWDER

pH IN SOLUTION

NEAR NEUTRAL

ALSO PROVIDES

Ca · Mg · TRACE ELEMENTS

Ca · Mg · TRACE

SHELF LIFE

INDEFINITE, KEPT DRY

ORIGIN

MILLED & BAGGED IN CALIFORNIA

CALIFORNIA

WHY WE MADE THIS ONE

We built Root Zone because our own plants couldn't wait either.

"We had a block that went in late and it showed. So we milled a batch to go into solution faster and drenched the worst rows — and by the following week you could see the line in the field between what we'd treated and what we hadn't."

"We had a block that went in late and it showed. The season-long bag was doing its job, just not on the timeline the plants needed. So we milled a batch to go into solution faster and drenched the worst rows with it — and by the following week you could see the line in the field between what we'd treated and what we hadn't."

That batch became Root Zone. It's still made the same way, on the same farm, by the people who needed it first.

That batch became Root Zone. Still made the same way, on the same farm.

PLACEHOLDER — REPLACE WITH THE FOUNDER'S OWN WORDS AND NAME

EVERY REMAINING DOUBT

Answered here so you don't have to go looking.

If your question isn't here, a grower on our team answers the phone. Not a chatbot, not a ticket queue.

Ask us anything

How is this different from the Minerals bag?

Same mineral, different job. Minerals feeds slowly all season; Root Zone goes into solution immediately at the root zone and releases bound phosphorus. Most growers eventually run both.

Will it spike my pH?

No. Potassium silicates sit at pH 10–12 and swing reservoirs. This is a near-neutral mineral — no pH-down needed, safe alongside your existing feed.

Will it clog my sprayer or drip?

At 2–4 microns it passes standard filtration and stays suspended with modest agitation. Pre-mix in a small volume first, keep agitation on long runs, rinse at the end.

How fast is "fast-acting", honestly?

Uptake starts with the first watering. Turgor changes in week one; structural benefits build over three to six weeks. Anyone promising 48 hours is selling something else.

Is it safe for my soil biology?

It feeds it. A near-neutral mineral doesn't sterilise anything, and better soil structure benefits the food web. For a biology focus, look at Silica + Microbes.

Which crops does it help?

Silicon accumulators most: grasses and cereals, cucurbits, tomatoes and peppers, strawberries, flowering crops, ornamentals and turf. Almost everything benefits from the stress-tolerance side.

Can I use it with my nutrients?

Yes. It isn't a fertiliser and doesn't replace your feed. Add it as its own step, not premixed into concentrated stock; in a reservoir, add it last.

How long will a bag last?

The 2 lb pouch covers about a season for a ten-plant home grow — around 24 applications. Kept dry and sealed, it doesn't expire.

Why does it sometimes run out mid-season?

We mill it in finite runs and won't stretch a batch with filler. In peak season a run can move in a few weeks — buy the size you need up front rather than counting on a July re-order.

What if it does nothing for my plants?

Tell us and we'll make it right — the 30-day guarantee.

CLIENT TO CONFIRM EXACT GUARANTEE TERMS.

How is this different from the regular Volcanic Silica Minerals?

Same volcanic mineral, different job. The Minerals bag is formulated for steady, season-long availability — you put it in at transplant and it feeds slowly. Root Zone is milled and formulated so a larger fraction goes into solution immediately, and it's specifically aimed at the root zone and at releasing bound phosphorus. Most growers eventually run both: Root Zone when something needs fixing now, Minerals as the baseline underneath.

Will it spike my pH like potassium silicate did?

No. Potassium silicate concentrates sit around pH 10–12, which is why they swing reservoirs and can trigger magnesium lockout. This is a mineral, not a caustic silicate — near neutral in solution, no pH-down needed, and safe alongside your existing feed. This is the single most common reason growers who quit silica come back to it.

Will the powder clog my sprayer or drip lines?

At 2–4 microns it passes through standard sprayer and drip filtration and stays suspended with modest agitation. Pre-mix in a small volume of water first rather than dumping it into a full tank, keep agitation running on long fertigation events, and rinse the line at the end as you would with any suspension. Commercial growers run it through drip and pivot systems routinely.

How fast is "fast-acting", honestly?

Uptake starts with the first watering after application. Visible turgor changes tend to show in the first week; structural benefits — stem stiffness, disease and heat resilience — build into new tissue over three to six weeks. Anyone promising a transformation in 48 hours is selling you something else. See the week-by-week timeline above.

Is it safe for my soil biology?

It feeds it rather than harms it. Unlike caustic silicates, a near-neutral mineral doesn't sterilise anything, and improved soil structure benefits the food web. If soil biology is your main focus, look at Silica + Beneficial Microbes, which adds Bacillus and mycorrhizal species on top of the mineral.

Which crops does it actually help?

Silicon accumulators benefit most: grasses and cereals, rice, sugarcane, cucurbits, tomatoes and peppers, strawberries, flowering crops, ornamentals and turf. Fruiting and flowering plants carrying heavy weight late in the season see the clearest structural payoff. Almost every crop benefits from the stress-tolerance side; the degree varies.

Can I use it with my existing nutrients?

Yes — it isn't a fertiliser and doesn't replace your feed programme. Add it as its own step rather than premixing into a concentrated nutrient stock, and if you're running a reservoir, add it last. It works alongside synthetic and organic programmes alike.

How long will a bag last me?

At the standard rate, the 2 lb pouch covers roughly a season for a home grow of about ten plants — around 24 applications. Eight pounds suits a large garden or a small market operation for a season; 40 lb is the commercial sack. Kept dry and sealed, unused product doesn't expire.

Why does it sometimes run out mid-season?

Because we mill it in finite runs and won't stretch a batch with filler. In peak season a run can move in a few weeks. If you're planning a full season, buy the size you need up front rather than counting on a re-order in July — or set up a season refill, which reserves your bag from the run before it goes on general sale.

What if it doesn't do anything for my plants?

Tell us and we'll make it right — that's the 30-day guarantee, and we'd rather refund you than argue. We'll also ask what you grew and how you applied it, because that feedback is how the next batch gets better.

CLIENT TO CONFIRM EXACT GUARANTEE TERMS.

30-day guarantee

Use it for a month. If your plants don't tell you it was worth it, we refund you. Client to confirm.

Use it a month. If your plants don't tell you it was worth it, we refund you. Client to confirm.

30-day guarantee

Use it for a month. If your plants don't tell you it was worth it, we refund you. Client to confirm.

Grown, not sourced

Mined, milled and bagged by the same family farm that uses it on its own crops.

Mined, milled and bagged by the family farm that uses it on its own crops.

A grower answers

Application questions go to someone who farms, usually the same day.

No subscription traps

Season refills are opt-in, skippable and cancellable in one click.

LAST THING

The plants you have right now are the ones this helps.

Silicon builds into new tissue, so every week you wait is growth that goes in without it. $37.95, a season for a home grow, refunded if it does nothing.

The plants you have right now are the ones this helps.

Silicon builds into new tissue, which means every week you wait is a week of growth that goes in without it. A 2 lb pouch is $37.95, covers a home grow for a season, and if it does nothing for you we'll refund it. That's about as low as we can make the risk of finding out.

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NOT READY TO BUY?

Take the Silica 101 guide instead.

Twelve pages on what silicon does and how to read a silica label. Free, no discount code attached.

Twelve pages on what silicon does, how to read a silica label, and how to tell whether your soil is short of it. Free, no discount code attached.

Silica Root Zone · 2 lb pouch

$37.95

ONLY 38 OF THIS BATCH LEFT IN 2 LB POUCH

Silica Root Zone · 2 lb pouch

$37.95

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