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 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.

FoxFarm's Big Bloom Plant Food is a liquid fertilizer with an N-P-K ratio of 0.01-0.03-0.7, which is quite low in nitrogen and phosphorus but has a higher potassium content. This makes it suitable for flowering and fruiting stages of marijuana growth. The product is organic, featuring ingredients like earthworm castings and bat guano, which can add a broad spectrum of micronutrients beneficial for healthy plant development.

It is designed to enhance root strength, improve flower fragrance, and boost essential oil production, which can be particularly useful for increasing the potency of marijuana plants. The fertilizer is safe for regular use on all types of flowering and fruiting plants, including marijuana. It comes in a liquid form that mixes easily with water, simplifying the application process.

Its low N-P-K ratio might not be sufficient for the vegetative stage when marijuana plants require higher levels of nitrogen and phosphorus for vigorous growth. Additionally, while it offers a comprehensive range of nutrients, users looking for a highly targeted fertilization approach may need to supplement it with additional products. This fertilizer is best suited for enhancing the bloom phase and should be paired with other products during the vegetative stage to meet all nutritional needs.