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10 Best Fertilizer For Marijuanas 2025 in the United States

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Our Top Picks

#1

Winner

FoxFarm Fertilizer Soil Trio Liquid Nutrient: Tiger Bloom, Grow Big, Big Bloom Bottles - (Pack of 3-1 Pint)

Rating
9.9
Chosen by1,206
Organic vs. Synthetic
Ease of Use

Most important from
23270 reviews

Organic vs. Synthetic
No bad smells or caustic chemicals.
Ease of Use
Very little goes a long way, and I only have to feed them about twice a week.

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.

Rating
9.9
Chosen by1,206
Organic vs. Synthetic
Ease of Use

Most important from
23270 reviews

Organic vs. Synthetic
No bad smells or caustic chemicals.
Ease of Use
Very little goes a long way, and I only have to feed them about twice a week.
#2

FoxFarm - Big Bloom Plant Food, Liquid Fertilizer Concentrate for Flowers, Fruits, and Vegetables, All Purpose Plant Fertilizer for Indoor & Outdoor Potted Plants, NPK 0.01-0.03-0.7 (Pint)

Rating
9.8
N-P-K Ratio
Type of Fertilizer
Micronutrients

Most important from
10893 reviews

N-P-K Ratio
The low NPK ratio may seem subtle, but it packs a punch with natural ingredients like bat guano and earthworm castings.
Type of Fertilizer
FoxFarm Big Bloom is a game-changer for any gardener, offering versatility and reliability across a range of plants, from vegetables to cannabis.
Micronutrients
Using Big Bloom as a foliar spray provides a quick nutrient boost, especially effective for houseplants and seedlings.
Ease of Use
The product's ease of use is enhanced by clear instructions, making it simple to adjust the dosage based on plant response.

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.

Rating
9.8
N-P-K Ratio
Type of Fertilizer
Micronutrients

Most important from
10893 reviews

N-P-K Ratio
The low NPK ratio may seem subtle, but it packs a punch with natural ingredients like bat guano and earthworm castings.
Type of Fertilizer
FoxFarm Big Bloom is a game-changer for any gardener, offering versatility and reliability across a range of plants, from vegetables to cannabis.
Micronutrients
Using Big Bloom as a foliar spray provides a quick nutrient boost, especially effective for houseplants and seedlings.
Ease of Use
The product's ease of use is enhanced by clear instructions, making it simple to adjust the dosage based on plant response.
#3

FoxFarm Grow Big Liquid Plant Food - Bloom Fertilizer for Flowers, Fruits, and Vegetables, Perfect for Indoor & Outdoor Potted Plants, NPK 6-4-4 (Quart)

Rating
9.6
Ease of Use

Most important from
7197 reviews

Ease of Use
For those growing Indica, expect nice flowers and chunky buds, especially when used 2-3 times per week for deep green color and rapid growth.

The FoxFarm Grow Big Liquid Plant Food is a versatile fertilizer suitable for a variety of plants, including marijuana. It features an N-P-K ratio of 6-4-4, which is beneficial for vegetative growth, supporting the development of healthy and robust plants. The fertilizer's unique blend includes organic components such as earthworm castings and Norwegian kelp, which provide essential nutrients without harmful chemicals, promoting stronger roots and better flavor in fruits, flowers, and vegetables.

It is easy to use by mixing 2-3 teaspoons per gallon of water, making the feeding process straightforward and hassle-free. With a significant user rating of 4.8 out of 5 stars from over 7,000 reviews, it is well-received by the gardening community. However, it is important to note that while it is marketed as suitable for all flowering and fruiting plants, users should monitor pH levels to ensure optimal nutrient uptake. Additionally, its liquid form may require careful handling and storage to avoid spills.

Given its comprehensive nutrient profile and ease of use, it is a strong choice for both novice and experienced growers looking to enhance plant growth and yield.

Rating
9.6
Ease of Use

Most important from
7197 reviews

Ease of Use
For those growing Indica, expect nice flowers and chunky buds, especially when used 2-3 times per week for deep green color and rapid growth.

Buying Guide for the Best Fertilizer For Marijuanas

Choosing the right fertilizer for your marijuana plants is crucial for ensuring healthy growth and maximizing yield. Fertilizers provide essential nutrients that plants need to thrive, and different stages of growth require different nutrient compositions. Understanding the key specifications of fertilizers will help you make an informed decision and select the best product for your needs.
N-P-K RatioThe N-P-K ratio represents the proportions of nitrogen (N), phosphorus (P), and potassium (K) in the fertilizer. These are the primary nutrients that plants need. Nitrogen is important for leaf growth, phosphorus for root and flower development, and potassium for overall plant health. During the vegetative stage, a higher nitrogen content (e.g., 3-1-2) is beneficial, while during the flowering stage, a higher phosphorus content (e.g., 1-3-2) is preferred. Choose a fertilizer with the appropriate N-P-K ratio based on the current growth stage of your plants.
Type of FertilizerFertilizers come in various forms, including liquid, granular, and slow-release. Liquid fertilizers are quickly absorbed and are ideal for immediate nutrient delivery, making them suitable for both vegetative and flowering stages. Granular fertilizers are sprinkled on the soil and provide nutrients over time, which can be useful for long-term feeding. Slow-release fertilizers gradually release nutrients over several months, reducing the need for frequent applications. Consider your growing setup and how often you want to fertilize when choosing the type of fertilizer.
Organic vs. SyntheticOrganic fertilizers are made from natural materials such as compost, manure, and bone meal, and they improve soil health over time. They release nutrients slowly and are less likely to cause nutrient burn. Synthetic fertilizers are chemically formulated and provide nutrients in a readily available form, which can lead to faster plant growth. However, they can also cause nutrient imbalances if not used correctly. If you prefer a more natural approach and are concerned about soil health, organic fertilizers are a good choice. If you need precise control over nutrient levels, synthetic fertilizers may be more suitable.
MicronutrientsIn addition to the primary nutrients (N-P-K), plants also need micronutrients such as calcium, magnesium, iron, and zinc in smaller amounts. These micronutrients are essential for various physiological functions and overall plant health. Some fertilizers include a complete range of micronutrients, while others may require you to supplement them separately. Ensure that your fertilizer provides a balanced mix of micronutrients to prevent deficiencies and promote optimal growth.
pH LevelThe pH level of the fertilizer affects the availability of nutrients to the plants. Marijuana plants prefer a slightly acidic pH range of 6.0 to 7.0 in soil and 5.5 to 6.5 in hydroponic systems. Some fertilizers are formulated to help maintain the desired pH level, while others may require you to adjust the pH separately. Regularly monitor the pH of your growing medium and choose a fertilizer that supports maintaining the optimal pH range for your plants.
Ease of UseConsider how easy the fertilizer is to use, including how it is applied and how often it needs to be administered. Some fertilizers come with clear instructions and pre-measured doses, making them user-friendly for beginners. Others may require more precise measurements and mixing. If you are new to growing marijuana or prefer a low-maintenance approach, look for a fertilizer that is straightforward to use and fits your routine.

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