All-Purpose Houseplant Food (Dry) 21-7-14
- Regular Price
- $ 0.00
- Sale Price
- $ 0.00
- Regular Price
Sold Out
- Unit Price
- per
Greenway Biotech · Made in California since 1989
All-Purpose Houseplant Food 21-7-14.
A clean teaspoon, dialed to the research.
A chloride-free, fully water-soluble powder built on the UF/IFAS 3:1:2 (N:P₂O₅:K₂O) optimum for container plants — then back-engineered so a level teaspoon lands on research-based ppm-nitrogen targets. Includes 2% magnesium, labeled sulfur, and a full chelated micronutrient package, with no filler to ship or store. Blended in our CDFA-registered, third-party lab-tested Madera facility.
Find your size → Calculate my dose3:1:2ratio
The UF/IFAS container-foliage optimum, held exactly
~140ppm N
All-purpose target from a level ½ tsp per gallon
0%Cl
Chloride-free sourcing for salt-sensitive containers
9nutrients
N-P-K plus Mg, S and six chelated micros in one scoop
01 / Choose your size
A little goes
a long way.
A level ½ teaspoon (~2.5 g) treats a full gallon of water. The estimates below assume an all-purpose every-other-watering program; lighter winter feeding stretches a bag much further, and constant low-dose feeding lands in the same range.
| Bag Size | Gallons of feed solution | Approx. plants for a season | Best For |
|---|---|---|---|
| 1 lb | ~180 gal | A handful of plants, a full year | Most popular |
| 2 lb | ~360 gal | A small collection, a full year | Avid plant parents |
| 5 lb | ~900 gal | A large collection or a sunroom | Serious growers |
| 10 lb | ~1,800 gal | Interior-scapes, offices, studios | Heavy use |
| 25 lb | ~4,500 gal | Greenhouses and growers-for-resale | Best value |
02 / Ideal applications
One scoop.
Most of your collection.
A 3:1:2 foliage-forward grade suits the bulk of common houseplants. Where a plant has special needs, we say so honestly below.
Foliage houseplants
Pothos, philodendron, monstera, ferns, dracaena and the like — the foliage-leaning 3:1:2 grade is built for exactly this group.
Tropicals & aroids
Supports steady leaf production through the bright growing season, with chelated micros to keep newer leaves from going pale.
Flowering houseplants
Works as a general feed for many flowering plants. For bloom-heavy growers wanting a higher-phosphate push, a dedicated bloom formula may suit better.
Herbs in pots
Light, frequent feeding keeps potted basil, mint and similar herbs productive without forcing soft, leggy growth.
Succulents & cacti
Use with restraint — feed at the lowest dose, infrequently, during active growth only. These plants want far less nitrogen than tropical foliage.
RO / distilled water growers
Pure water supplies no calcium. This food is calcium-free by design, so growers on RO or inert media should add calcium separately — never tank-mixed with this product.
03 / Why this food
Formulated for pots.
Not scaled down from a field bag.
This grade was validated against interior-foliage requirements rather than carried over from field-crop logic. Five findings shaped the final formula.
3:1:2
The research-backed ratio, held exactly.
UF/IFAS reports that for container-grown plants a fertilizer near a 3:1:2 N:P₂O₅:K₂O ratio produces the greatest growth. Most houseplants are foliage plants, so 3:1:2 is the backbone. A filler-free, chloride-free source set lands naturally at 21-7-14 — the same ratio at higher analysis, with about a third less ballast to ship and store.
NO₂
Nitrate-leaning nitrogen for cool, low-light rooms.
Interior containers are exactly where ammonium stress and substrate-pH decline are most likely, so nitrate-leaning nitrogen is preferred. Potassium nitrate carries the nitrate fraction; the balance comes from urea, so there is no free ammonium sitting in the bag. The deliberate nitrate-boost strategy is assigned to our companion liquid concentrate, where high solubility is an asset.
0%Cl
Chloride-free, salt-managed sourcing.
Container houseplants are sensitive to soluble-salt accumulation. Chloride-free sourcing, moderate dose rates, and simple leaching guidance keep root-zone salts in check — a meaningful difference for plants living in a fixed, limited volume of media.
2%Mg
Magnesium and sulfur, built in.
Magnesium sits at the center of every chlorophyll molecule. We carry it as Epsom salt (magnesium sulfate), which also retains 2.7% sulfur as a labeled secondary nutrient — and, being moisture-stable, keeps the dry blend from drawing in humidity the way a nitrate magnesium source would.
6
A complete chelated micro package.
Chelated iron (DTPA), manganese, zinc and copper (EDTA), plus boron and molybdenum, in ratios chosen for foliage: an iron-dominant manganese-to-iron balance that guards against interveinal chlorosis, with boron held safely inside its narrow tolerance window.
04 / The science
Why 3:1:2 wins in a pot.
21-7-14N-P₂O₅-K₂O
An exact 3 : 1 : 2 ratio, filler-free
Container plants do not behave like field crops. They live in a small, fixed volume of media, often under low indoor light, watered on a human schedule rather than by rainfall. Research on container-grown ornamentals points to a nitrogen-forward ratio near 3:1:2 as the grade that supports the most growth across the broad mix of foliage plants people keep indoors.
Holding that ratio while removing chloride and filler is a sourcing problem. A familiar 12-4-8 grade cannot be built as a fully water-soluble powder without roughly a third of the bag being inert diluent, because no good soluble inert filler exists. The same clean source set, without that ballast, lands at 21-7-14 — an identical 3:1:2 ratio at higher analysis. You ship and store less dead weight, and you dose less powder per gallon to hit the same nitrogen target.
That target is the real design goal. The whole formula is back-engineered so a level ½ teaspoon per gallon delivers about 140 ppm nitrogen — squarely inside the 100–200 ppm range the potted-plant literature recommends for actively growing plants. You are not guessing at strength; the scoop is the dose.
For deeper coverage of the underlying nutrient roles, see The Function of Nitrogen in Plants, The Function of Potassium in Plants, and The Function of Magnesium in Plants.
05 / Dosing
Pick your season.
Get your dose.
Every dose below is back-engineered to a research-based nitrogen concentration (ppm N). The formula: ppm N = grams of powder per gallon × %N × 2.642, with a level teaspoon of this powder calibrated to about 5 grams.
All-purpose, every-other watering
Quick answer: ½ teaspoon per gallon at every-other watering (≈140 ppm N) is the default program for most foliage houseplants in active growth.
| Dose / gallon | Approx. weight | ppm N | When to use |
|---|---|---|---|
| ½ tsp | ~2.5 g | ~140 | General all-purpose, every-other watering |
| ¾ tsp | ~3.75 g | ~210 | Fast growers in bright light, vigorous foliage |
Note: Feed during active growth (spring–summer and bright periods). Dissolve fully in room-temperature water; do not apply to bone-dry media — moisten first to avoid root burn. Leach each pot thoroughly (water until ~15–20% drains) every 4–6 feedings to flush accumulated salts.
Sources: UF/IFAS EDIS ST297 and EP261 (Broschat) - 3:1:2 container optimum and ornamental nutrition; UMass Extension Greenhouse & Floriculture - ppm-N constant-feed ranges and dilution math.
Constant feed, every watering
Quick answer: ¼ teaspoon per gallon at every watering (≈70 ppm N) keeps a steady, gentle supply for plants you water often.
| Dose / gallon | Approx. weight | ppm N | When to use |
|---|---|---|---|
| ¼ tsp | ~1.25 g | ~70 | Constant feed at every watering, maintenance |
| ½ tsp | ~2.5 g | ~140 | Constant feed for vigorous growers in bright light |
Note: Both constant feed at the lower rate and periodic feed at the higher rate land within the research-recommended range — choose whichever fits your watering habit. Still leach every 4–6 feedings to flush salts.
Sources: UMass Extension Greenhouse & Floriculture - constant-feed ppm-N ranges; UConn Home & Garden Education Center - houseplant fertilization guidance.
Winter, dormancy & deep shade
Quick answer: Step down to ⅛–¼ teaspoon per gallon, or pause feeding entirely, when growth slows in winter or low light.
| Dose / gallon | Approx. weight | ppm N | When to use |
|---|---|---|---|
| ⅛ tsp | ~0.6 g | ~35 | Winter / dormant / very low light |
| ¼ tsp | ~1.25 g | ~70 | Slow growth, low light, maintenance only |
Note: Reduce or stop feeding in winter dormancy and deep shade — this is the practical control on the urea-dominant nitrogen. A plant that is not actively growing cannot use the nitrogen you give it, and excess simply accumulates as salt in the pot.
Sources: MSU Extension - nitrate-leaning N-form selection for cool, low-light interiors; UF/IFAS EDIS ST297 (Broschat).
06 / How to use & calculate
Dissolve.
Feed.
Flush.
Mix it fresh, feed during active growth, and leach the pot periodically. The calculator turns your watering habit into the right dose and the right bag.
-
01
Dissolve fully first
Stir the measured powder into room-temperature water until completely dissolved. Never sprinkle dry powder onto the soil surface.
-
02
Moisten, then feed
Apply to already-moist media, not bone-dry soil — feeding into dry media concentrates salts at the roots and risks burn. Feed during active growth and ease off in winter.
-
03
Leach to flush salts
Every 4–6 feedings, water the pot thoroughly until about 15–20% drains from the bottom. This flushes accumulated salts and keeps root-zone conductivity in check.
-
04
Keep calcium separate
This food is calcium-free by design. If you supplement calcium (e.g. Calcium Nitrate or Cal-Mag Plus), apply it on a separate watering — never tank-mixed with this product.
07 / Compare
Which feed
fits the job?
This dry powder is the all-purpose backbone for soil-grown containers. Where your setup is different — recirculating hydroponics, bloom-forward, or a magnesium-only fix — a more specialized product may fit better.
| Product | Grade | Form | Best For | Notes |
|---|---|---|---|---|
| Houseplant Food 21-7-14 (this product) | 21-7-14 + 2Mg | Dry powder | All-purpose feeding of soil-grown foliage houseplants | Chloride-free, calcium-free; dosed by the teaspoon to ppm-N targets |
| Grow Green 4-2-6 | 4-2-6 | Dry concentrate | Vegetative stage in hydroponic and coco programs | Part of the 4-part hydroponic system; pairs with Cal-Mag & Micro Green |
| Blossom Green 2-6-8 | 2-6-8 | Dry concentrate | Bloom-forward feeding of flowering plants | Higher phosphate and potash for flower set; bloom-stage of the 4-part system |
| Cal-Mag Plus 2-0-0 | 2-0-0 + Ca/Mg/Fe | Dry concentrate | Adding calcium on RO water or inert media | The calcium companion this food intentionally omits; apply separately |
| Epsom Salt | 0-0-0 + Mg/S | Dry crystals | Correcting a standalone magnesium deficiency | Single-nutrient Mg + S; this food already includes 2% Mg and 2.7% S |
08 / Decision
Is this the right
food for you?
An honest split — where this dry all-purpose powder shines, and where another product earns the spot.
Best Choice For
- Soil- and mix-grown foliage houseplants in containers
- Growers who want a single all-purpose feed for a mixed collection
- Anyone who prefers dosing by the teaspoon to a known nitrogen target
- Salt-sensitive or chloride-sensitive plants
- Plant parents who like a moisture-stable dry powder with a long shelf life
- Tropicals, aroids, ferns, herbs, and most flowering houseplants
Consider Another Product If
- You run a recirculating hydroponic system — build a reservoir program with the 4-part hydroponic line instead
- You want a bloom-forward, higher-phosphate push — try Blossom Green 2-6-8
- You grow on RO or inert media and need calcium — add Cal-Mag Plus on a separate watering
- You only need to fix a magnesium deficiency — Epsom Salt is the single-nutrient option
- You prefer a ready-to-pour liquid — our companion liquid houseplant concentrate may suit better
09 / Build the program
A great all-purpose feed.
These round it out.
A few companions cover the cases this food deliberately leaves out — calcium, a bloom push, and a standalone magnesium fix.
Calcium + N
Calcium Nitrate 15.5-0-0
The calcium this food omits by design. Apply on a separate watering day for RO-water and inert-media growers.
Cal + Mg + FeCal-Mag Plus 2-0-0
A chelated calcium, magnesium and iron supplement for coco, RO and distilled-water setups. Add separately, never tank-mixed.
Bloom pushBlossom Green 2-6-8
A higher-phosphate, bloom-forward feed for flowering houseplants that want more than an all-purpose ratio at flower set.
MagnesiumEpsom Salt
A single-nutrient magnesium and sulfur source for spot-correcting a confirmed Mg deficiency between regular feedings.
10 / Safety & handling
Read this before
you feed.
A concentrated, hygroscopic blend that contains an oxidizer. A little care in storage and mixing keeps it working and keeps you safe.
- Keep sealed in a cool, dry place and reseal immediately after each use — this is a hygroscopic blend, and caking is a sign of moisture pickup.
- Contains potassium nitrate, an oxidizer. Keep away from heat, strong acids and combustible organics, and store separately from incompatible chemicals.
- Always dissolve fully in water before applying; never feed into bone-dry media. Keep the solution off foliage where possible and water it in at the roots.
- Do not tank-mix with any calcium-bearing product (Calcium Nitrate, Cal-Mag). If used, apply calcium products on a separate watering.
- Keep out of reach of children and pets. On eye or skin contact, flush with water; if swallowed, do not induce vomiting and contact Poison Control or seek medical attention. Refer to the SDS for complete handling guidance.
11 / FAQ
Common questions.
Honest answers.
If your question isn't here, contact our team at questions@greenwaybiotech.com.
How much do I use per gallon?
For most foliage houseplants in active growth, use a level ½ teaspoon per gallon (about 2.5 g), which works out to roughly 140 ppm nitrogen — squarely in the range research recommends for actively growing potted plants. Step up to ¾ teaspoon for fast growers in bright light, and down to ⅛–¼ teaspoon in winter or low light. The calculator above will do the math for any water volume.
Can I feed at every watering?
Yes. A ¼ teaspoon per gallon (about 70 ppm N) at every watering is a gentle constant-feed program, and a ½ teaspoon every other watering lands in the same overall range. Both are within research-recommended ranges — pick whichever fits your watering habit. Either way, leach the pot every 4–6 feedings to flush salts.
Why is there no calcium in it?
Calcium cannot share a single bag with phosphate and sulfate without forming insoluble precipitates, so it is left out by design. Peat-based mixes and ordinary tap water normally supply enough calcium. Growers using RO or distilled water on inert media should add calcium separately — for example Calcium Nitrate or Cal-Mag Plus — on a separate watering, never tank-mixed with this product.
What does chloride-free actually mean for my plants?
Container houseplants live in a small, fixed volume of media and are sensitive to soluble-salt buildup. Chloride is one of the salts that can accumulate. By sourcing the formula chloride-free and keeping doses moderate, the product helps keep root-zone salts in check, which research links to better tolerance in salt-sensitive plants. Periodic leaching does the rest.
Is this the same as your liquid houseplant concentrate?
They are a deliberate pair. This dry powder is the high-analysis, all-purpose feed that holds the 3:1:2 ratio and keeps magnesium as moisture-stable Epsom salt. The companion liquid concentrate carries the higher-nitrate strategy, where its more hygroscopic magnesium source is no problem because it is already in solution. Use whichever format you prefer — both target the same research-based ratio.
Can I use it on succulents and cacti?
Yes, with restraint. Feed at the lowest dose, infrequently, and only during active growth. Succulents and cacti want far less nitrogen than tropical foliage, so treat the winter/low-light column as your normal rate for them rather than the all-purpose rate.
Will it cake or go bad in the bag?
It is a naturally hygroscopic blend, which is exactly why magnesium is carried as moisture-stable Epsom salt rather than a deliquescent nitrate. Keep it sealed in a cool, dry place and reseal right after each use. Caking is a sign the powder has picked up moisture; it can still be dissolved, but store it more tightly going forward.
Is it safe around children and pets?
Like any concentrated fertilizer, keep it sealed and out of reach. It also contains potassium nitrate, an oxidizer, so store it away from heat and incompatible chemicals. On eye or skin contact, flush with water; if swallowed, do not induce vomiting and contact Poison Control or seek medical attention. Refer to the SDS for full handling guidance.
Is it CDFA registered and lab tested?
It is blended in our CDFA-registered, third-party lab-tested facility in Madera, California, the same operation we have run as a family business since 1989. Our products are tested for heavy metals, with results consistently well below required limits. The product label and SDS for this new SKU are being finalized and will be posted here shortly.
Ready to feed?
Pick your bag. We'll ship it.
Available from a 1-pound pouch up to a 25-pound bag, so you can match the size to a single windowsill or a full greenhouse. Free shipping on orders over $100, and a 90-day full-refund guarantee on every size.
Choose your size →