Your greenhouse fertilizer program will involve nitrogen (mostly in the form of nitrate), potassium, phosphorus, sulfur, calcium, magnesium, and the micronutrients in your water source. To start, you will want to get your water source and growth medium tested to establish if they need treatment or conditioning. Some growth mediums like coco coir require special considerations and adjustments to nutrient schedules to account for its ability to immobilize nitrogen.

Next, you will want to decide what type of nutrients you want to use. There are many options from organic fertilizers like guano, worm castings, and manure. There are also products that provide organic plant nutrition in a liquid form. If possible, consider a natural or organic bottle nutrient over a fully synthetic bottle nutrient because they will provide more wholesome nutrition that encourages beneficial root bacteria to flourish. Remember that as your plants grow and mature, your fertilization rates will change. That means you'll need to monitor nutrient levels and adjust them when plants mature and enter a new growth stage.