The most decisive phase of the year is about to hit outdoor growers. All the previous months' planning is finally about to be put into motion, with focus shifting to execution. Dr. Craig Yendrek, Research Principal for General Hydroponics R&D, is very much aware how crucial this step is. "Outdoor cultivation is often treated as being easier than indoor cultivation. But there are complex interactions between soil chemistry, water quality and nutrient delivery that require attention before plants even go into the ground."
Building the foundation with soil and water analytics
When it comes to either hemp or cannabis outdoor cultivation, soil testing is the first crucial step to achieve precision. For instance, a soil pH between 6.2 and 6.5 is of the utmost importance, because nutrient availability is dictated by pH balance. Outside of that range, even well formulated feeding programs can underperform due to nutrient lockout.
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Annual analytical testing allows growers to account for existing nutrient credits already present in the field. "Residual nitrogen, phosphorus, potassium, calcium, magnesium and sulfur levels all inform how feeding schedules should be adjusted, preventing both overapplication and hidden deficiencies," Dr. Yendrek points out. Water quality plays an equally important, as potential contaminants can directly impact nutrient uptake and long-term soil stability. "You can have perfect soil and still struggle if your water chemistry is working against you."
Precision delivery through fertigation
As operations scale, fertigation has become a standard tool for uniform nutrient delivery across large outdoor fields. Using injectors calibrated to a 1:100 dilution ratio allows for consistent dosing and straightforward calculations, particularly when paired with water soluble powders.
However, compatibility at the concentrate level remains a critical consideration. Calcium based inputs must be kept separate from phosphorus and sulfur concentrates to avoid precipitation. These are typically managed through Part A and Part B tanks, remaining separate until diluted and mixed at the emitter.
Uniform wetting is the final piece of the delivery puzzle. Drip tape spacing in the 8-to-12- inch range ensures nutrients reach the active root zone without excessive leaching, especially during peak summer demand.
Stage-specific nutrition in the field
At General Hydroponics, Dr. Yendrek and his team built out their FloraPro Commercial outdoor program around stage specific precision, starting at transplant. "Applying a starter charge of 1 lb per 100 gallons of FloraPro Grow at planting does a great job to jump start plant growth in order to quickly establish new transplants," Dr. Yendrek explains. As daylength approaches 14 hours or visible pre-flower sex determination appears, nutrient demands shift. "This is the signal to transition from Grow to Bloom formulas, aligning fertility with the plant's reproductive phase. Fertilization is stopped 7 days prior to harvest, allowing plants to finish cleanly while avoiding residual buildup in the soil or final biomass."
Optimizing the outdoor season. To support large scale producers during this outdoor season, FloraPro is currently offering early access for exclusive pre-season pricing. Click here to get started.
For more information:
General Hydroponics
1-888-808-4826
[email protected]
generalhydroponics.com
