How a Small Hydroponic Microgreens Farm Generates High Output in Limited Space

Overview of a Soil-Free, Low-Labor Production Model

This article examines a hydroponic microgreens operation producing high annual revenue within approximately 1,200 square feet, using no soil and minimal manual labor. The system is designed around automation, modular equipment, and simplified workflows that reduce daily intervention.

The discussion is based entirely on a second-part farm walkthrough explaining how seeding, germination, watering, nutrient delivery, and infrastructure choices function together in a compact production environment.

Core Differences From Conventional Microgreens Production

Eliminating Soil and Traditional Media

The operation does not use soil or traditional growing substrates. Instead, crops are grown on fiber mats placed in mesh trays, allowing water and nutrients to reach plant roots directly from below.

This approach removes the need for:

Soil mixing
Soil disposal
Media reuse management

Because nutrients can only reach plants through the mesh tray, root development is mandatory before entering the main grow system.

Seeding Workflow and Tray Preparation

Mobile Seeding Cart Design

All seeding activities are performed on a movable cart, which can be rolled directly to a sink for wetting fiber mats. This reduces lifting and transport steps.

Process sequence:

Fiber mats are removed from storage
Mats are placed into mesh trays
Mesh trays sit inside low-cost bottom trays (used only for handling)
Mats are watered at the sink
Trays are stacked and transferred to the seeding area

The bottom trays used at this stage are explicitly described as fragile and unsuitable for long-term use. Durable trays are recommended for all production and stacking functions.

Automated Seeder and Consistent Distribution

The farm uses a mechanical seeder to distribute seeds evenly across wet fiber mats.

Key advantages noted:

Uniform spacing across the entire tray
Elimination of clumping
Reduced mold risk caused by seed density
No requirement for weighing individual seed portions

The seeder allows 8–10 trays to be seeded in a single pass, depending on table spacing.

Manual seeding previously required nearly a full day of labor and introduced labeling errors during density experiments. With the seeder, total weekly seeding time is reduced to 1–2 hours in most cases.

Germination Requirements in a Hydroponic System

Importance of Early Root Development

Unlike systems where moisture surrounds the growing medium, this hydroponic setup requires roots to physically reach the water layer.

Trays remain in the germination tent until:

2 days of growth are visible
Roots begin emerging through the bottom of the mat

Without this root development, plants cannot access water or nutrients after transfer.

Managing Moisture and Mold Risk

Excess water is identified as the primary cause of mold in fiber mats. If mats remain constantly wet, mold forms regardless of airflow or fungicide use.

Attempts to mitigate this included:

Increased airflow
Air stones beneath trays

These methods proved ineffective once root systems thickened.

The farm plans to replace fiber mats with silicone mats, which do not harbor moisture or organic residue. This change is intended to reduce mold pressure by removing absorbent material entirely.

Light Spectrum Considerations

The operator mentions potential experimentation with green-spectrum LED lighting, which theoretically penetrates deeper into dense canopies. The goal would be to:

Encourage lower stem transpiration
Reduce trapped moisture near the mat surface

This experiment is described as future-facing and dependent on energy-efficiency grant funding.

Seed Handling, Storage, and Sanitation

Intensive Seed Preparation

Certain crops undergo extensive preparation, including:

Multiple rinses
Soaking cycles
Bleach soaking (for some varieties)
Pre-germination in jars

This process removes dust and foreign particles prior to seeding.

Airtight, Mobile Seed Storage

Seeds are stored in airtight containers mounted on wheels, rather than original supplier bags.

Benefits include:

Protection from pests
Easier scooping and pouring
Improved organization
Reduced contamination risk

Each container is labeled with crop type and lot number for traceability.

Crop-Specific Seeding Adjustments

Use of Vermiculite

Vermiculite is not used universally. It is applied only for amaranth due to:

Extremely dense seeding rates
Higher mold pressure

The vermiculite layer helps regulate surface moisture during emergence. Once silicone mats are introduced, partial removal of vermiculite after emergence is planned to maximize stem yield.