FoxFarm Grow Big Fertilizer 6-4-4 | 16oz - Concentrate

Vegetative Structure Builder for Soil Gardens, 16oz

Building a plant's frame during the vegetative stage sets the ceiling for how much it can produce later, and a fertilizer that's unstable in storage or locks up micronutrients works against that goal. FoxFarm Grow Big 6-4-4 is a liquid concentrate formulated at a low pH to stay stable on the shelf and keep micronutrients available in solution, aimed at building plant size and branching structure ahead of bloom.

The 16oz bottle is sized for smaller gardens and hobbyist growers working with a handful of plants rather than a full commercial vegetative room.

Key Features & Benefits

• 6-4-4 NPK Ratio — higher nitrogen relative to phosphorus and potassium, aimed at vegetative growth, size, and structural development.
• Low-pH Formulation — keeps the concentrate stable in storage and helps micronutrients stay available in solution.
• Liquid Concentrate — mixes with water for use as a soil drench or through drip and irrigation lines.
• Builds Toward Bloom — stronger vegetative structure supports more fruit, flower, and bud sites once the plant transitions to flowering.
• Part of the FoxFarm Soil Program — works alongside Big Bloom and Tiger Bloom in the FoxFarm Soil Feed Schedule.

Who Should Use Grow Big 6-4-4

Soil growers focused on the vegetative stage who want a low-pH liquid concentrate that keeps micronutrients in solution are the fit for Grow Big 6-4-4, especially those already running Big Bloom and Tiger Bloom alongside it.

About FoxFarm Grow Big

Grow Big is one of the three original FoxFarm soil-formula liquid fertilizers, manufactured since the early 1980s by the Humboldt County, California, company, and formulated specifically for the vegetative stage of a soil feeding schedule.

Frequently Asked Questions

What NPK ratio does Grow Big 6-4-4 provide?

It's a 6-4-4 ratio, with nitrogen ahead of phosphorus and potassium to drive vegetative growth, plant size, and structural development. That nitrogen-forward balance is what distinguishes it from FoxFarm's bloom-stage formulas.

Is Grow Big 6-4-4 a liquid or granular fertilizer?

It's a liquid concentrate that gets diluted with water before use, applied as a soil drench or through drip and irrigation systems. It isn't sold in a granular form.

When should I stop using Grow Big and switch to bloom nutrients?

Run Grow Big through the vegetative growth phase, then transition to a phosphorus-forward bloom fertilizer such as FoxFarm Tiger Bloom at the first sign of flowers or bud development. Continuing Grow Big much past that point isn't necessary once flowering is underway.

Does Grow Big 6-4-4 work in hydroponic systems?

Grow Big 6-4-4 is formulated for soil use. FoxFarm sells a separate Grow Big Hydroponic 3-2-6 formula specifically for soilless, hydroponic growing environments.

Can I use Grow Big 6-4-4 alongside other FoxFarm fertilizers?

Yes, it's part of the FoxFarm soil feeding program and is designed to work alongside Big Bloom and Tiger Bloom. Refer to the FoxFarm Soil Feed Schedule for combined dosing guidance.