This Week's Focus in the Greenhouse
This week in the greenhouse, our team focused on preparing live pepper plants for the start of shipping season. The first round of plant shipments is scheduled to begin the week of April 6th, so much of our work right now is centered on making sure plants are healthy, stable, and ready for the transition from greenhouse to home gardens across many different growing regions.
Alongside preparing plants for shipment, we continue planting new flats and closely monitoring greenhouse conditions as temperatures both inside and outside the greenhouse begin to change. This time of year in Iowa often brings significant temperature swings, making careful climate management inside the greenhouse especially important.
Live Pepper Plants: Production Update
Current Growth Stage
Pepper plants throughout the greenhouse remain in the seedling stage, with our oldest pepper plants now reaching approximately 13–14 weeks of growth.
At this stage, plants continue developing stronger root systems and fuller foliage as they move closer to the next phase of production and the upcoming shipping window.
Maintaining multiple growth stages inside the greenhouse allows us to plant continuously while preparing the oldest plants for shipment.
Ghost pepper plants at approximately 13–14 weeks old, moving closer to shipping readiness. We might need to start naming them, we've been checking in on this tray of plants every week.
Environmental Conditions We're Monitoring
Temperature management has become a key focus as outdoor spring conditions continue to warm.
To help regulate internal greenhouse temperatures, we recently opened and activated our lower circulation fans and turned on the wet wall cooling system.
A wet wall works through evaporative cooling. Water continuously flows down a corrugated pad along one wall of the greenhouse while large fans pull outside air through the damp surface. As the air passes through the wet pad, it cools before circulating throughout the greenhouse and also helps .
These systems help improve airflow and prevent temperatures from rising too quickly as sunlight warms the greenhouse during the day.
The greenhouse wet wall cooling system helps regulate temperatures by cooling incoming air as outdoor conditions warm.
Observations & Challenges
Faster Growth from Fertilizer Adjustments
One observation this week is that some pepper plants are growing more quickly than expected due to adjustments made to fertilizer rates compared to last year's growing schedule.
While healthy growth is always the goal, plants growing too quickly can create challenges when timing shipments and maintaining the ideal plant size for delivery.
Adjustments Made
To keep growth rates on track, fertilizer levels are being adjusted for certain varieties that are developing faster than planned. This helps ensure plants remain strong while staying within the optimal size range for shipping.
While it is normal to see some variation in growth rates between pepper varieties, the difference has been more noticeable this season, so we are adjusting accordingly.
The trays shown were planted on the same date but contain two different pepper varieties that are developing at slightly different speeds.
Seed Stock Production
There are no major updates for seed stock production this week.
Seeds that were previously planted for both the Dutch Bucket production area and for local grower partners continue progressing through early growth stage helping maintain consistent seed availability throughout the season.
Dragon's Breath seedlings started in rockwool are developing in preparation for the Dutch Bucket system in our greenhouse, where plants grow in individual containers with controlled irrigation and nutrients.
At the same time, seeds planted in seed-starting potting mix for our local grower partners have also successfully germinated. These partner growers cultivate plants to maturity and harvest the peppers for seed, helping support consistent seed availability throughout the season.
Two approaches to seed stock production: Dragon's Breath seedlings growing in rockwool for greenhouse Dutch Bucket production (left) and 7 Pot Primo Chocolate seedlings started in seed-starting mix for local grower partners (right).
Looking Ahead
With the first week of live plant shipping approaching, the team will continue focusing on:
• Monitoring plant size and growth rates
• Maintaining stable greenhouse temperatures
• Preparing plants for safe shipment
• Carefully managing irrigation and fertilizer schedules
These final preparations help ensure plants leave the greenhouse healthy, stable, and ready to establish quickly once they arrive at their new home with you.
What This Means for Home Growers
Preparing pepper plants for shipping is one of the most important phases of greenhouse production.
By carefully managing plant size, environmental conditions, and transplant preparation, we help reduce transplant shock and give plants the best chance of thriving once they arrive in home gardens.
The work happening now inside the greenhouse helps ensure the plants you receive are healthy, well-rooted, and ready to continue growing once they reach your garden.
Each of these Sugar Rush Stripey pepper plants will receive its own label and will be packaged in the green blister packs shown below, which are designed to protect the plant during transit.
A Few Notes from the Greenhouse
Small Win
This week marked another important milestone as we began preparing plants for the first week of shipping on April 6th, bringing months of planting and early care one step closer to reaching growers.
We're all excited to see these plants arrive in their new homes and continue growing in gardens across the country and hopefully ending up in plenty of spicy recipes.
Separating rockwool cubes earlier helps reduce transplant shock, giving plants time to adjust before they transition from the greenhouse to their new home with you.
Keep Up with the Greenhouse
Missed a week?
👈 Week 10: Last Week's Update
Want to see how the season started?
👉 Start at Week 1
Stay spicy friends,
🌶️ The Pepper Joe's Growing Team