10 Best Fertilizer For Marijuanas 2025 in the United States

Organic Plant Magic's Truly Organic Fast-Acting Water Soluble Plant Food is a powder fertilizer designed to support a wide range of plants, including marijuana. It is an organic fertilizer that avoids synthetic chemicals and relies on natural ingredients like amino acids, humic acids, kelp, and beneficial microbes to nourish plants. This product contains over 55 trace minerals and beneficial biology such as mycorrhizae, which can help improve soil health and plant nutrient uptake.

The powder form is water-soluble and easy to use — simply mix it with water and apply directly to soil or plants, making it convenient for both beginners and experienced growers. Its coverage is quite efficient, treating up to 1,000 square feet with just a half-pound bag, which can be mixed into 32 gallons of water.

This fertilizer is a strong choice for growers seeking a natural, nutrient-rich feeding option that supports plant health and flavor without synthetic additives. It may not provide the precise nutrient control of specialized marijuana fertilizers but offers a balanced and effective solution for overall plant nourishment.

The CANNA Growing Nutrients Set is a liquid fertilizer kit designed to support various growth stages of marijuana plants, including root development, vegetative growth, and flowering. It combines several products like Canna Coco A + B, Rhizotonic, Cannazym, Boost, and PK 13/14, which together provide a balanced supply of essential nutrients. The inclusion of PK 13/14 indicates strong support for the flowering phase, which is crucial for producing large buds. This set is synthetic-based, offering precise nutrient control and easy absorption, but it may not appeal to those seeking fully organic options. The liquid form allows for flexible and straightforward mixing, though beginners might find mixing ratios challenging.

Weighing about 16 pounds with multiple components, this set is well-suited for medium-scale grows. It provides a comprehensive and reliable nutrient system for marijuana plants without requiring growers to manage complex nutrition details.

The FoxFarm Fertilizer Soil Trio is a solid choice for those looking to enhance their marijuana plants. This trio includes Grow Big, Big Bloom, and Tiger Bloom, which are designed to work together to support healthy growth, flowering, and fruit production. The N-P-K ratios in these fertilizers cater to different growth stages, with Tiger Bloom focusing on phosphorus to boost flowering, while Grow Big supports vegetative growth. This balanced approach allows growers to provide targeted nutrition throughout the plants' life cycles.

One of the product's great strengths is its organic status, with Big Bloom being OMRI Listed, making it a suitable option for those who prefer organic gardening. The ease of use is another plus; you can apply them regularly with each watering, simplifying the feeding routine. This makes it ideal for beginners who may not have extensive experience with fertilizers.

However, there are a few drawbacks to consider. Some users have noted that the liquid formulation can be messy if not handled carefully, and it may require precise measurements to avoid over-fertilizing. Additionally, while it's great for supporting plant growth, the need for three different products might be overwhelming for novice gardeners who are just starting out.