Ghost Pepper Seedlings at five weeks old grown hydroponically in the greenhouse in rockwool.

Weekly Greenhouse Update: Sanitizing, Seed Planting, and Heat Mats

This Week’s Focus in the Greenhouse

This week, our primary focus was finishing the sanitization of our flood tables in preparation for the seedling season. Thorough cleaning and sanitizing help reduce the risk of disease and create a healthier environment for young plants as they begin to grow.

These behind-the-scenes steps may not be visible once plants are established, but they play an important role in long-term plant health and consistency.

Ghost Pepper seedlings growth at 5 weeks

Live Pepper Plants: Production Update

Current Growth Stage

Earlier this week, our team planted 5,880 seeds intended for live plant production into rockwool. Our oldest seedlings are now five weeks old, check out the Ghost Peppers from last week in the picture above. At this stage, plants are still small but actively establishing their root systems and early structure, which sets the foundation for stronger growth later on.

What are flood tables?
Flood tables are raised growing surfaces that allow water to be evenly delivered to seedling trays from below. This bottom-watering approach helps maintain consistent moisture while keeping foliage dry, supporting healthier seedlings during early growth. 

Once the flood tables were fully sanitized, the team was ready to begin watering seedlings and supporting the next stage of early growth.

A flood table in action below: water circulating from the pump (left) shortly after beginning and rising to the target level just above the bottom of the seedling trays (right) during bottom watering.

Before and after view of greenhouse flood tables showing water circulating from the pump and rising to the target level just above the bottom of the seedling trays during bottom watering.

About rockwool:
Rockwool is a sterile growing medium that retains moisture while allowing plenty of airflow to developing roots. It’s commonly used in greenhouse production to support consistent germination and early root growth.

Recent Changes in Care

Maintaining stable conditions is especially important during early seedling growth. This week, the greenhouse team continued monitoring:

    • Temperature: Maintained at approximately 75°F

    • Humidity: Kept at a minimum of 60%

    • Lighting: Artificial lighting is used to support consistent seedling growth

To support germination, we also added heating mats beneath select seedling trays.

Chocolate Habanero seedlings with humidity dome and tray sitting on a heat mat.

Why the Change Matters

Some varieties, including chocolate habanero, can experience slower germination. Adding bottom heat gently warms the growing medium, which can help increase and speed up germination for more temperature-sensitive varieties.

Small adjustments like this allow the team to respond quickly when certain plants need a little extra support.

Growing Plants for Seed Production

Varieties Grown for Seed

There are no updates to seed stock production this week. Our team shifted priorities to focus on live plant production, so plans to deseed Dragon’s Breath and Moruga Trinidad Scorpion peppers have been temporarily paused. This kind of flexibility is a normal part of working in a dynamic greenhouse environment.

How Seed Production Differs from Live Plant Growing

Plants grown for seed follow a different growing path than those intended for transplanting into home gardens. These plants remain in the greenhouse longer and require ongoing monitoring to support healthy fruit development for seed harvest.

Quality Control This Week

No quality control updates this week.

Observations & Challenges

What Didn’t Go as Planned

No challenges to report this week.

Ongoing Challenges

No ongoing concerns were observed during this period.

How We Adjust

Next week, the team will closely monitor the humidity domes covering seedling trays. If excess condensation builds up or water begins dripping from the domes, they’ll be cracked open for a few hours to release excess humidity.

What do humidity domes do?
Humidity domes help retain moisture around seedlings during early growth. As plants develop, excess humidity needs to be released gradually to prevent issues and encourage stronger growth.

What This Means for Home Growers

The sanitation work, environmental monitoring, and small adjustments happening now help support healthier seedlings and more consistent growth later in the season. From improving germination rates to maintaining clean growing spaces, these early efforts help ensure plants are set up for success, whether they’re shipped as live plants or grown from seed at home.

A Few Personal Notes from the Greenhouse

  • Small Win: We’re seeing excellent germination rates, with some varieties reaching 90% or higher, a great sign as the season gets underway.
  • Learning Moment: This week reinforced the importance of proper PPE use in the greenhouse. Wearing gloves and masks, and washing hands thoroughly after handling wet or dry peppers, helps protect both plant health and personal safety.
  • Variety Spotlight: In addition to peppers, we're also growing several varieties of tomato plants in the greenhouse. These plants are growing tall and have already begun producing tomatoes.
Tomato plants grown in the greenhouse producing fruit.

Stay spicy and and thanks for checking in on the greenhouse,

🌶️The Pepper Joe’s Growing Team 

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