Uncle Pete's Organic Grow and Flower Formulas are based upon a feed, feed, water schedule of Monday, Wednesday, Friday. Giving the plant time to consume its food and water and allowing the Pro-Mix to dry between applications is a programmatic way to prevent water stress. However, different cannabis varieties and individual plants of different sizes consume food and water at different rates. For plants to thrive, the gardener must be observant in order to avoid over- and under-watering. By lifting each pot, the gardener can easily determine how much water remains in the Pro-Mix. With time and experience the gardener can approximate moisture levels by looking at the plant itself and the surface of the Pro-Mix, and stop lifting pots.
Uncle Pete's Formula targets the following feed rates for Monday and Wednesday:
The size of container you choose for your plants should be based on the final size of the plants and the number of plants under each light, allowing the plants to dry the Pro-Mix substantially, but not completely, between each application.
On Monday and Wednesday, lift each pot before feeding to check its moisture level. If the pot is still heavy, feed less. If the pot is very light, feed a little more. On Friday use the watering solution (described in the Optimizing Vegetative Growth and Optimizing Marijuana Flowering topics) to slowly and thoroughly drench each pot until there is a small amount of runoff. Friday's watering goal is to ensure even moisture levels for all plants, in order to restart the feed schedule on Monday.
When plants are growing aggressively in optimally-sized containers, the Pro-Mix dries substantially between feed and water applications. This creates some spots within the Pro-Mix which are drier than others, and become slightly hydrophobic, i.e. more difficult to moisten. It is important to apply the solution slowly to make sure the Pro-Mix has even moisture throughout.
The easiest way to ensure thorough and even watering is to apply half the targeted amount of solution twice, allowing 30 minutes to an hour between applications. This ensures that moisture levels are even, and that solution is not lost via runoff.
The details described in this topic are deceptively simple. As always, environment control is crucial to getting consistent behavior. If the temperature, humidity, light, or ventilation of your garden are inconsistent, it will be difficult or impossible to get consistent behavior from your plants. If your plants display signs of water stress, if the Pro-Mix is drying out too early or staying too wet, revisit this topic, read it carefully, then re-evaluate your garden. Incorporate your own experience with your own plants and garden into this evaluation to dial in the perfect moisture levels for your plants through each day of their life cycle. Your plants cannot thrive if they experience water stress.