Watering Cannabis: When, How, and How Much?

Watering cannabis isn’t just about the timing and amount—it also depends on various environmental factors and plant conditions. Understanding these can help you adapt your watering practices for healthier, more resilient plants.

Organic vs. No-Till Gardening

Organic Gardening: This approach focuses on periodic “dry backs” between waterings to encourage root growth and nutrient cycling, improving soil aeration and preventing root issues.

No-Till Gardening: Here, a consistent moisture level is key, as it supports the soil’s microbial life and mycelium networks. This approach reduces the risk of disrupting beneficial soil organisms.

How Much to Water

Generally, you’ll want to water with 5-10% of the soil’s total volume. For example, a 10-gallon pot would need around 1 to 1.5 gallons of water. Using a moisture meter can help ensure you stay within ideal moisture levels, particularly for no-till systems where soil moisture consistency is vital.

Other Contributing Factors

1. Humidity and Temperature: In dry, hot conditions, soil tends to dry out faster, while high humidity can retain soil moisture longer. Adjust your watering schedule based on these factors.
2. Plant Size and Growth Stage: Larger plants and those in later growth stages will generally consume more water, requiring more frequent checks and adjustments.
3. Soil Composition: Soil with higher clay content retains water longer, whereas sandy soils may drain more quickly. Adjust your watering amount and frequency to accommodate your soil type.
4. Container Type and Size: Fabric pots allow more airflow and quicker drying than plastic ones, while larger pots may hold moisture longer due to the larger soil volume.
5. Vapor Pressure Deficit (VPD): Monitoring VPD can help you maintain the right balance between temperature and humidity, which influences how fast your plants use water. A balanced VPD ensures optimal transpiration and can help you fine-tune your watering schedule.

By taking these factors into account, you’ll be able to adapt your watering approach to meet your plants’ specific needs and promote a thriving growing environment for cannabis.