10 Best Organic Slow Release Plant Food of 2025

Tested and Reviewed: Top 10 Organic Slow Release Plant Food deals with expert ratings from 8.1 to a perfect 10

March 2026 Edition

Editor's Choice

9.7

RAINFLOW

RAINFLOW 11.28 OZ Slow Release Fertilizer - Organic Plant Food All Purpose Plant Fertilizer for Succulents Cactus Orchid Bonsai and All Other Outdoor & Indoor Garden

Editor's bottom line:

“This organic slow release plant food is the best one we tested. In terms of quality, brand and price, we couldn't ask for more.”

Main Highlights

Balanced Nutrient Formula: This slow release fertilizer contains 14-13-13 NPK to provide comprehensive nutritional support to promote healthy plant growth and is suitable for various gardening and agricultural needs
Organic Fertilizer for Plants: Our organic plant food is made with a special slow release technology that releases nutrients for up to 180 days, reducing the frequency of fertiliser applications and saving time and effort
Slow Release Plant Fertilizer: This garden fertilizer not only enhances plant root development and loosens the soil, but also promotes flowering and fruiting, giving plants nutrition and protection
Versatile Applications: Our all purpose plant fertilizer is suitable for orchids, succulents, cacti, vegetables and many other flowers and plants, providing balanced nutrients suitable for different kinds of plants and gardening projects
Easy to Use: The granular fertilizer is easy to spread and mix, suitable for home gardening and large scale planting. Beginners and gardening enthusiasts can easily get started without complicated fertilizer application operations

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Picked by 397 people today

9.5

Save 14%

Osmocote

Osmocote Smart-Release Plant Food Plus Outdoor & Indoor₁, Granular Fertilizer with 11 Essential Nutrients, 2 lbs.

14% Off

Main Highlights

Osmocote Smart-Release Plant Food Plus Outdoor & Indoor granular plant food contains 11 essential nutrients and feeds live plants up to 6 full months
This fertilizer works with virtually all plant varieties and growing conditions
Each granule is coated with a unique resin that controls nutritional release so plants get what they need when they need it
Osmocote offers a no-burn pledge, when used as directed
One 2 lb. container of Osmocote Smart-Release Plant Food Plus Outdoor & Indoor covers up to 75 sq. ft.

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Best Value

9.5

Save 31%

Osmocote

Osmocote Smart-Release Plant Food Flower & Vegetable, 8 lb.

31% Off

Main Highlights

OSMOCOTES HIGHEST TOTAL NUTRIENT FORMULA: NPK = 14-14-14. Favored for seasonal vegetables and perennials. Promotes strong roots as well as vigorous and bountiful above-ground growth
OSMOCOTES DIRECTIONS FOR USE: 1 lb. covers 40 sq. ft. (approx. 6½ x 6½). Mix into 1 3 of soil. Applicator included. Apply to vegetable gardens and mulched areas around ornamental trees / shrubs, and raised beds
OSMOCOTE QUALITY: Osmocote is the original slow-release plant food. Decades of rigorous field testing confirm product effectiveness with hundreds of plant species in a variety of climate and soil conditions
OSMOCOTES SECRET: Soil temperature controls how Osmocote releases its nutrients, and importantly how nutrients are taken up by the plant. Replenishment and feeding are in natural harmony
OSMOCOTE IS MISTAKE-PROOF: Even if over-applied up to 3x the recommended rate, Osmocote does not burn the plant

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9.2

Save 18%

Osmocote

Osmocote Smart-Release Plant Food Plus Outdoor & Indoor, 1 lb.

18% Off

Main Highlights

Our best formula, fortified with 11 essential nutrients
Works with virtually all plant varieties, in all growing conditions
Feeds up to 6 full months
Apply with confidence to potted plants, indoors or outdoors
No-burn pledge when used as directed

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9.0

True Organic

True Organic All Purpose Plant Food – Organic Fertilizer for Fruits, Vegetables, Flowers, and Herbs – 4lb Bag Covers 87 sq. ft.

Main Highlights

Balanced Nutrition for All Plants: True Organic All Purpose Plant Food promotes abundant organic fruits, vegetables, flowers, herbs, and foliage with a well-rounded formula.
Prevents Soil Depletion: Contains 5% nitrogen (3.75% slow-release), 4% phosphate, 5% potash, 4% calcium, and 1% sulfur to nourish plants and enrich soil.
Exclusive Organic Blend: Includes seabird guano, shrimp and crab shell meal, soybean meal, and fish bone meal for a nutrient-packed, eco-friendly fertilizer.
Versatile and Easy to Apply: Ideal for in-ground and container plants, this fertilizer is simple to apply monthly during the growing season for optimal growth.
Flexible Sizing for Any Garden: Available in 4lb (covers 87 sq. ft.), 4.5lb shaker jug (97 sq. ft.), 8lb (174 sq. ft.), 12lb (261 sq. ft.), and 25lb (544 sq. ft.) bags to fit gardens of any size.

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8.8

RAINFLOW

RAINFLOW 11.28OZ Slow Release Fertilizer - 17-17-17 Organic Plant Food All Purpose Plant Fertilizer for Most Potted,Fruit & Vegetable,Bulbs,Flowering,Leafy Plants Indoor & Outdoor Garden Fertilizers

Main Highlights

Balanced Nitrogen Fertilizer Formula: This slow release fertilizer contains 17-17-17 NPK to provide complete nutritional support for lush foliage and healthy plant growth and is suitable for various gardening and agricultural needs
Organic Fertilizer for Plants: Our organic plant food is made with a special slow release technology that releases nutrients for up to 60 days, reducing the frequency of fertiliser applications and saving time and effort
Slow Release Plant Fertilizer: Our garden fertilizer not only supports strong root systems and improves soil structure but also promotes vigorous stems and thick leaves. It provides essential nutrition for overall plant vitality
Versatile Applications: Our all purpose plant fertilizer is suitable for a variety of plants, including vegetables, flowers, and shrubs. It provides balanced nutrition for different plant types and various gardening projects, from small potted plants to large landscapes
Easy to Use: The granular fertilizer is easy to spread and mix into the soil. Its ideal for both home gardening and large-scale planting. Gardeners of all skill levels can apply it easily without complicated procedures

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8.6

Grow Queen

Grow Queen All-in-One Complete Organic Plant Food, Indoor Plant Food for Houseplants, Organic Fertilizer for Vegetable Gardens, 7 Formulated Single Servings Feeds 14 gal Fast and Slow Release

Main Highlights

VERSATILE APPLICATIONS & HEALTHY ROOTS: This versatile plant food is excellent as a complete food for indoor potted plants & hanging pots, as well as a superb microbe inoculant and starter for garden bedsindoors or out. It also reduces transplant shock, promoting rapid, vigorous root growth, offering advantages over liquid fertilizers in root development.

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8.3

Organic Plant Magic

Organic Plant Magic - Truly Organic™ Fast-Acting Water Soluble Plant Food - All-Purpose Fertilizer Concentrate for Flower, Vegetable, Herb, Fruit Tree, Garden & Indoor Houseplants [One 1/2 lb Bag]

Main Highlights

New Package - Same Amazing Product that Plants & Customers LOVE!
EASY & ALL PURPOSE - Simply grow healthy plants and beautiful gardens... Just add directly to seed, soil, transplant roots, existing plants, or mix with normal watering. Works for everyone, every plant, everywhere, every time!
A LITTLE GOES A LONG WAY - 1/2 lb bag makes 32+ gallons or treats up to 1,000 sf of soil or plants. Provides benefits of compost and advanced nutrition that builds healthy nutritious living soil and feeds plants continuously on-demand.
AMAZING GROWTH, COLOR, & FLAVOR - Empower your plants to express their full genetic potential. Get intense leaf, flower, fruit, veggie and herb production. Grow more vibrant color and flavor than ever before.
BIOLOGY OVER CHEMICALS - This unique versatile powder is packed with every essential plant nutrient, plus 55+ trace minerals, amino acids, humic acids, kelp, and beneficial GroBiotics including mycorrhizae proven to provide everything your plants need to naturally grow their best!

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8.1

EarthPods

EarthPods® Premium Indoor Plant Food Capsules (100 Count) – Slow-Release Organic Fertilizer Spikes | Specialized Nutrients for Houseplants | Made in USA

Main Highlights

Push in & water simplicity one capsule feeds for 30 days; no mixing, no salt crust on soil.
True organic boost 100% plant stable nutrients deliver balanced nutrition naturally.
Zero odor, zero mess clear vegan capsule dissolves fully; perfect for desks & apartments.
Wide-spectrum nutrition feeds all indoor plants without switching formulas.
Planet-friendly packaging recyclable FSC paper tube; family-run Earthworm Technologies since 2012.

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8.1

Save 15%

Osmocote

Osmocote Smart-Release Plant Food Plus Outdoor & Indoor₁, Granular Fertilizer with 11 Essential Nutrients, 8 lbs.

15% Off

Main Highlights

Osmocote Smart-Release Plant Food Plus Outdoor & Indoor granular plant food contains 11 essential nutrients and feeds live plants up to 6 full months
This fertilizer works with virtually all plant varieties and growing conditions
Each granule is coated with a unique resin that controls nutritional release so plants get what they need when they need it
Osmocote offers a no-burn pledge, when used as directed
One 8 lb. container of Osmocote Smart-Release Plant Food Plus Outdoor & Indoor covers up to 300 sq. ft.

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Our Best Overall Choice

Best Choice

9.7

RAINFLOW

RAINFLOW 11.28 OZ Slow Release Fertilizer - Organic Plant Food All Purpose Plant Fertilizer for Succulents Cactus Orchid Bonsai and All Other Outdoor & Indoor Garden

Editor's bottom line:

“This is the best one we tested. In terms of quality, brand and price, we couldn't ask for more.”

Main Highlights

Balanced Nutrient Formula: This slow release fertilizer contains 14-13-13 NPK to provide comprehensive nutritional support to promote healthy plant growth and is suitable for various gardening and agricultural needs
Organic Fertilizer for Plants: Our organic plant food is made with a special slow release technology that releases nutrients for up to 180 days, reducing the frequency of fertiliser applications and saving time and effort
Slow Release Plant Fertilizer: This garden fertilizer not only enhances plant root development and loosens the soil, but also promotes flowering and fruiting, giving plants nutrition and protection
Versatile Applications: Our all purpose plant fertilizer is suitable for orchids, succulents, cacti, vegetables and many other flowers and plants, providing balanced nutrients suitable for different kinds of plants and gardening projects
Easy to Use: The granular fertilizer is easy to spread and mix, suitable for home gardening and large scale planting. Beginners and gardening enthusiasts can easily get started without complicated fertilizer application operations

Show Price

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