Growing Radish in a Greenhouse:

What PAR, CO₂, and VPD Taught Me About Speed, Roots, and Quality Radish is one of those crops that looks incredibly simple.Short cycle. Fast growth. Strong flavor. Because of that, I originally treated radish as a “no-problem” crop and focused mostly on timing. That was a mistake. Once I started growing radish in a greenhouse […]

Growing Romaine Lettuce in a Greenhouse:

What PAR, CO₂, and VPD Taught Me About Structure, Speed, and Leaf Quality Romaine lettuce looks tougher than butterhead or loose-leaf lettuce. The upright shape and thick midrib make it feel forgiving, so at first I treated it almost like a “light-hungry” leafy crop. That approach didn’t last long. Once I started growing romaine seriously […]

Growing Scallions in a Greenhouse:

What I Learned About PAR, CO₂, and VPD Through Real Growth Cycles Scallions are often treated as a low-effort crop. They grow quickly, tolerate cutting, and rarely collapse dramatically when something is off. Because of that, I used to think they didn’t need much environmental attention. That assumption turned out to be wrong. Once I […]

Growing Green Onions in a Greenhouse:

What PAR, CO₂, and VPD Taught Me About Speed, Texture, and Regrowth Green onions (scallions) look simple. They grow fast, tolerate cutting, and seem much less fragile than lettuce. Because of that, I originally treated them as a “low-attention” crop. That assumption didn’t last long. Once I started growing green onions seriously in a greenhouse—and […]

Growing Bok Choy in a Greenhouse: What PAR, CO₂, and VPD Taught Me About Fast Crops and Fragile Balance

Bok choy looks like a forgiving crop.It grows fast, it looks sturdy, and on paper it tolerates a wide range of conditions. Because of that, I initially treated it as a “set it and forget it” leafy green. That assumption didn’t last long. Once I started measuring PAR, CO₂, and VPD instead of relying on […]

Growing Mustard Greens in a Greenhouse:

What I Learned About PAR, CO₂, and VPD by Actually Growing Them I used to think mustard greens were almost “foolproof.” They grow fast, they tolerate cold, and they don’t look demanding on paper. But once I started growing them seriously in a greenhouse — and measuring PAR, CO₂, and VPD instead of guessing — […]

Growing Tarragon in a Greenhouse:

What I Learned About PAR, CO₂, and VPD Through Trial and Error Tarragon taught me a lesson that many other herbs didn’t:you can’t force it. When I first grew tarragon in a greenhouse, I treated it like basil or rosemary. I increased light, dried the air slightly, and expected faster growth. Instead, the plants slowed […]

Growing Chives in a Greenhouse:

How PAR, CO₂, and VPD Change Across Growth Stages (From Real Grower Experience) Chives are often described as “easy herbs,” but when I actually started growing chives in a controlled greenhouse environment, I realized how sensitive they are to light balance and humidity stress—especially if you want fast regrowth and tender leaves instead of thin, […]

PAR, CO₂, and VPD Requirements for Greenhouse Swiss Chard at Different Growth Stages

When I first started growing Swiss chard in my greenhouse, I treated it like most leafy greens: give it bright light, consistent water, and a balanced soil mix. In the early weeks that approach seemed to work well — seedlings developed leaves quickly — but as plants grew larger I began noticing pronounced differences in […]

PAR, CO₂, and VPD Requirements for Greenhouse Arugula at Different Growth Stages

When I first started growing arugula in my greenhouse, I approached it much like I did other leafy greens: give it bright light, consistent moisture, and balanced soil nutrients, and it should grow quickly. In the early weeks that approach seemed to work — seedlings developed leaves rapidly — but as plants matured I began […]

PAR, CO₂, and VPD Requirements for Greenhouse Sage at Different Growth Stages

When I first began growing sage in my greenhouse, I assumed it would be as straightforward as other Mediterranean herbs: plenty of light, well-drained soil, and moderate water should be enough. In the earliest stages that approach seemed to work — seedlings sprouted and the first aromatic leaves appeared. But as plants matured I started […]

PAR, CO₂, and VPD Requirements for Greenhouse Oregano at Different Growth Stages

When I first started growing oregano in my greenhouse, I treated it like most other Mediterranean herbs I had grown: give it plenty of light, moderate water, and well-drained soil, and it will thrive. In the first few weeks, seedlings developed quickly and leaves opened with the expected aroma. However, as plants matured, I began […]

PAR, CO₂, and VPD Requirements for Greenhouse Thyme at Different Growth Stages

When I first started growing thyme in my greenhouse, I treated it much like other Mediterranean herbs: plenty of light, modest water, and good soil structure should be enough. In the earliest stage that approach seemed adequate, but as plants matured I began seeing differences in leaf density, aroma strength, and overall growth vigor that […]

AH-PARDLI: A Bluetooth PAR Meter That Works Anywhere — No Internet Required

When I first started measuring light for my plants, I depended on apps and internet lookups to understand what a reading meant. If I couldn’t connect to Wi-Fi, the meter sat idle. That changed when I began using the AH-PAR/DLI meter, a Bluetooth PAR meter that works anywhere without needing an internet connection. This article […]

What Are the Units of PAR and Why Do They Matter?

When I first started measuring light for my plants, I quickly realized that the hardest part was not the measurement itself, but understanding the units. I kept seeing numbers written as µmol/m²/s, along with terms like PAR and PPFD. At first, they felt abstract and disconnected from what I was actually seeing in my garden. […]