Comparison: Best Slow Acting Granular Fertilizer (Updated | Nov 11th)
If you’re looking to give your lawn or garden a long-lasting boost without the hassle of frequent feeding, slow-acting granular fertilizers are your best bet. They release nutrients gradually, promoting steady growth and reducing the risk of burn. But with so many options out there, how do you know which one truly delivers? In this comparison, we’ve tested top contenders based on effectiveness, value, and ease of use—so you can skip the guesswork and choose the right fertilizer with confidence. Let’s find your garden’s perfect match.
Editor’s Choice
Best for a specific purpose
- Best for all-purpose classic: Southern Ag All Purpose Granular Fertilizer 10-10-10
- Best for 6-month release: Osmocote Smart-Release Plant Food Plus Outdoor & Indoor₁
- Best for large 6-month: Osmocote Smart-Release Plant Food Plus Outdoor & Indoor₁
- Best for balanced 8-week: 10-10-10 Plant Fertilizer Slow Release – 10 10 10 All Purpose Granular Garden Fertilizer for Vegetables
- Best for organic powerhouse: Organic Plant Magic – Truly Organic™ Slow Release Granular Fertilizer : Long-Lasting Plant Food Granules – Indoor & Outdoor Flowers
- Best for premium balanced: 10-10-10 Plant Fertilizer Slow Release – 10 10 10 All Purpose Granular Garden Fertilizer for Vegetables
- Best for high capacity: 10-10-10 Plant Fertilizer Slow Release – 10 10 10 All Purpose Granular Garden Fertilizer for Vegetables
- Best for 110-day green: Slow Release Lawn Fertilizer 25-5-10 NPK – 65% Granular Nitrogen Formula for Deep Feeding up to 110 Days – 10kg (22lbs) Bag – Kid & Pet Safe Lawn Care for Lush Green Grass
- Best for indoor premium: 10-10-10 Slow-Release Premium Fertilizer – All-Purpose Plant Food for Indoor Outdoor Gardening Vegetables Flowers Lawn Trees Shrubs
- Best for micronutrient boost: Supply Solutions 10-10-10 Complete Lawn & Garden Granular Fertilizer with Micronutrients – Balanced NPK Plant Food for Soil Health
Product Comparison: Best Slow Acting Granular Fertilizer
All-Purpose Classic
Southern Ag All Purpose Granular Fertilizer 10-10-10, 5 LB Size: 5 LB
Southern Ag
6-Month Release
Osmocote Smart-Release Plant Food Plus Outdoor & Indoor₁, Granular Fertilizer with 11 Essential Nutrients, 2 lbs.
Osmocote
- Osmocote Smart-Release Plant Food Plus Outdoor & Indoor₁ 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 & Indoor₁ covers up to 75 sq. ft.
Large 6-Month
Osmocote Smart-Release Plant Food Plus Outdoor & Indoor₁, Granular Fertilizer with 11 Essential Nutrients, 8 lbs.
Osmocote
- Osmocote Smart-Release Plant Food Plus Outdoor & Indoor₁ 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 & Indoor₁ covers up to 300 sq. ft.
Balanced 8-Week
10-10-10 Plant Fertilizer Slow Release – 10 10 10 All Purpose Granular Garden Fertilizer for Vegetables, Tomato, Arborvitae, Shrubs, Rose, Flowers, Fruit, Fig Trees (1 Quart)
GARDENWISE
- 🌿 Balanced 10-10-10 Granular Fertilizer for Outdoor & Indoor Plants: All-purpose plant food with 10% Nitrogen, 10% Phosphorus, and 10% Potassium. Perfect for outdoor vegetable gardens, fruit trees, evergreens, shrubs, lawns, and flowers. Also great for potted plants and indoor gardening. One solution for all your plant needs!
- ⏳ Slow-Release Formula for Continuous Outdoor Feeding: Provides up to 8 weeks of sustained nutrition with fewer applications. Ideal for outdoor lawns, vegetable gardens, fruit trees, and flowering plants. Apply twice per season for gardens and three times per year for trees and shrubs. Less work, more growth!
- 🌼 Promotes Strong Roots, Lush Growth, and Vibrant Outdoor Blooms: Phosphorus supports root health, Nitrogen fuels lush green leaves, and Potassium enhances plant resilience. Perfect for outdoor flowers, tomatoes, peppers, roses, evergreens, and shrubs. Enjoy thriving plants, colorful blooms, and abundant harvests!
- 🌱 Easy-to-Apply Granules for Even Outdoor Coverage: Fine granules spread evenly for maximum soil absorption in outdoor gardens, lawns, and landscapes. Ideal for pines, oaks, banana trees, fig trees, and ornamentals. Just spread, water, and watch your outdoor garden flourish!
- ⚡ Quick-Release Nitrogen for Immediate Outdoor Results: Instant nitrogen boost for rapid growth, combined with slow-release feeding for lasting results. Perfect for outdoor grass lawns, evergreen trees, flowering plants, and vegetables. See your outdoor garden thrive quickly and sustainably!
Organic Powerhouse
Organic Plant Magic – Truly Organic™ Slow Release Granular Fertilizer : Long-Lasting Plant Food Granules – Indoor & Outdoor Flowers, Vegetable Gardens, Fruit Trees, Shrubs, House Plants [One 4 lb Bag]
![Organic Plant Magic - Truly Organic™ Slow Release Granular Fertilizer : Long-Lasting Plant Food Granules - Indoor & Outdoor Flowers, Vegetable Gardens, Fruit Trees, Shrubs, House Plants [One 4 lb Bag]](https://m.media-amazon.com/images/I/51HyQUTD-WL._SL500_.jpg)
Organic Plant Magic
- New Spreadable Fertilizer Granules – Amazing Benefits that Plants & Customers LOVE!
- EASY & ALL PURPOSE – Simply grow healthy plants and beautiful gardens… Just add granules to planting holes, mix with soil, or top dress soil by hand or spreader. Works for everyone, every plant, everywhere, every time!
- LONG LASTING – Simply sprinkle a handful of Organic Plant Magic onto the soil of your plant once per month or more and water as normal for long lasting magical results! One 4 lb bag covers 1000 square feet.
- AMAZING GROWTH, COLOR, & FLAVOR – Empower your plants to express their full genetic potential. Get spectacular leaf, flower, fruit, veggie and herb production. Grow more vibrant color and flavor than ever before.
- BIOLOGY OVER CHEMICALS – This versatile all purpose granular blend 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!
Premium Balanced
10-10-10 Plant Fertilizer Slow Release – 10 10 10 All Purpose Granular Garden Fertilizer for Vegetables, Tomato, Arborvitae, Shrubs, Rose, Flowers, Fruit, Fig Trees (2 QUARTS)
GARDENWISE
- 🌿 Balanced 10-10-10 Granular Fertilizer for Outdoor & Indoor Plants: All-purpose plant food with 10% Nitrogen, 10% Phosphorus, and 10% Potassium. Perfect for outdoor vegetable gardens, fruit trees, evergreens, shrubs, lawns, and flowers. Also great for potted plants and indoor gardening. One solution for all your plant needs!
- ⏳ Slow-Release Formula for Continuous Outdoor Feeding: Provides up to 8 weeks of sustained nutrition with fewer applications. Ideal for outdoor lawns, vegetable gardens, fruit trees, and flowering plants. Apply twice per season for gardens and three times per year for trees and shrubs. Less work, more growth!
- 🌼 Promotes Strong Roots, Lush Growth, and Vibrant Outdoor Blooms: Phosphorus supports root health, Nitrogen fuels lush green leaves, and Potassium enhances plant resilience. Perfect for outdoor flowers, tomatoes, peppers, roses, evergreens, and shrubs. Enjoy thriving plants, colorful blooms, and abundant harvests!
- 🌱 Easy-to-Apply Granules for Even Outdoor Coverage: Fine granules spread evenly for maximum soil absorption in outdoor gardens, lawns, and landscapes. Ideal for pines, oaks, banana trees, fig trees, and ornamentals. Just spread, water, and watch your outdoor garden flourish!
- ⚡ Quick-Release Nitrogen for Immediate Outdoor Results: Instant nitrogen boost for rapid growth, combined with slow-release feeding for lasting results. Perfect for outdoor grass lawns, evergreen trees, flowering plants, and vegetables. See your outdoor garden thrive quickly and sustainably!
High Capacity
10-10-10 Plant Fertilizer Slow Release – 10 10 10 All Purpose Granular Garden Fertilizer for Vegetables, Tomato, Arborvitae, Shrubs, Rose, Flowers, Fruit, Fig Trees (3 QUARTS)
GARDENWISE
- 🌿 Balanced 10-10-10 Granular Fertilizer for Outdoor & Indoor Plants: All-purpose plant food with 10% Nitrogen, 10% Phosphorus, and 10% Potassium. Perfect for outdoor vegetable gardens, fruit trees, evergreens, shrubs, lawns, and flowers. Also great for potted plants and indoor gardening. One solution for all your plant needs!
- ⏳ Slow-Release Formula for Continuous Outdoor Feeding: Provides up to 8 weeks of sustained nutrition with fewer applications. Ideal for outdoor lawns, vegetable gardens, fruit trees, and flowering plants. Apply twice per season for gardens and three times per year for trees and shrubs. Less work, more growth!
- 🌼 Promotes Strong Roots, Lush Growth, and Vibrant Outdoor Blooms: Phosphorus supports root health, Nitrogen fuels lush green leaves, and Potassium enhances plant resilience. Perfect for outdoor flowers, tomatoes, peppers, roses, evergreens, and shrubs. Enjoy thriving plants, colorful blooms, and abundant harvests!
- 🌱 Easy-to-Apply Granules for Even Outdoor Coverage: Fine granules spread evenly for maximum soil absorption in outdoor gardens, lawns, and landscapes. Ideal for pines, oaks, banana trees, fig trees, and ornamentals. Just spread, water, and watch your outdoor garden flourish!
- ⚡ Quick-Release Nitrogen for Immediate Outdoor Results: Instant nitrogen boost for rapid growth, combined with slow-release feeding for lasting results. Perfect for outdoor grass lawns, evergreen trees, flowering plants, and vegetables. See your outdoor garden thrive quickly and sustainably!
110-Day Green
Slow Release Lawn Fertilizer 25-5-10 NPK – 65% Granular Nitrogen Formula for Deep Feeding up to 110 Days – 10kg (22lbs) Bag – Kid & Pet Safe Lawn Care for Lush Green Grass
Eco Solutions
- Feel Proud of Your Lawn – Slow release lawn fertilizer packed with 65% granular nitrogen – this spring lawn fertilizer feeds up to 110 days for deep green grass and lush growth you’ll love coming home to.
- Green Grass Starts Here – High nitrogen lawn food starter fertilizer with a 25-5-10 NPK blend delivers quick and steady growth – perfect grass food to revive tired lawns and kickstart your lawn care routine.
- Pet Friendly Peace of Mind – Safe for kids & pets – enjoy your outdoor space with confidence. Our pet friendly fertilizer for lawns is safe when used as directed and lets families play barefoot without worry.
- Healthy Roots, Happy Lawn – Granular fertilizer that works with both slow and quick release nitrogen. This lawn fertilizer includes enhanced sulphur and potassium from sulphate of potash for a safe, natural boost to soil health and deep root growth.
- For Every Lawn, Every Season – Trusted lawn feed from residential yards to sports fields, this spring fertilizer performs season after season – your go-to grass fertilizer for lawn care that actually delivers.
Indoor Premium
10-10-10 Slow-Release Premium Fertilizer – All-Purpose Plant Food for Indoor Outdoor Gardening Vegetables Flowers Lawn Trees Shrubs, 0.5 Quart
Bigmeta
- Balanced Nutrition for Healthy Growth: Our 10-10-10 fertilizer provides Nitrogen, Phosphorus, and Potassium in equal amounts, giving your plants the nutrients they need for strong roots, vibrant blooms, and lush growth.
- Efficient Nutrient Release: Our fast-dissolving formula delivers essential nutrients to your plants right after application, promoting immediate growth and providing ongoing nourishment for an extended period—making it easy to keep your garden thriving.
- Fast-Acting and Easy to Use: Designed with a professional-grade formula, it delivers nutrients quickly to help your plants grow healthier and stronger, with visible results in no time. Sprinkle it on moist soil or lightly bury it for effortless fertilizing.
- Safe and Reliable Ingredients: Crafted with high-quality, naturally sourced ingredients, our fertilizer is free from synthetic additives, ensuring a safe and enjoyable gardening experience for you and your plants.
- Suitable for All Plants: This all-purpose fertilizer is perfect for flowers, vegetables, fruit trees, and ornamental plants. It works for any garden, making it a go-to choice for all gardeners.
Micronutrient Boost
Supply Solutions 10-10-10 Complete Lawn & Garden Granular Fertilizer with Micronutrients – Balanced NPK Plant Food for Soil Health, Blooms & Roots – Safe for Vegetables, Fruits, Lawns (50 Pounds)
Supply Solutions
- Balanced 10-10-10 NPK Formula: A 10% nitrogen, 10% phosphorus, and 10% potassium blend ensures steady growth for lawns, gardens, and crops. Nitrogen fuels lush foliage, phosphorus boosts blooms/fruits, and potassium strengthens roots. Ideal for year-round use without nutrient overload.
- Micronutrient Enriched: Corrects soil deficiencies with Boron, Manganese, Copper, Iron, and Zinc. Perfect for crops needing targeted nutrition—apply 10-40 lbs/acre based on soil tests. Compatible with compost and NPK blends for precision farming.
- Nutripaction Technology: Low-dust, uniform granules break down gradually, releasing nutrients into the root zone. Matches bulk density (70 lbs/cu ft) of most fertilizers for seamless blending and even spreading.
- Soil Health & pH Balance: Stabilizes soil pH and boosts microbial activity with Verdesian Exchange Resin. Enhances nutrient bioavailability for healthier plants. Safe for vegetables, fruits, and lawns—soil application only.
- Easy Application: Free-flowing granules ensure hassle-free mixing and spreading. Use for soil prep, regular feeding, or correcting deficiencies. Consult local agronomists for tailored plans—ideal for beginners and experts.
Product prices and availability are accurate as of the date/time indicated and are subject to change. Any price and availability information displayed on Amazon.com at the time of purchase will apply to the purchase of this product.
Buying Guide
FAQs
What should I look for when choosing a slow‑release granular fertilizer?
Focus on the N‑P‑K ratio, release mechanism (coated granules vs plain slow‑release), and coverage area per bag. Also consider whether you need added micronutrients, organic ingredients, or a no‑burn guarantee for sensitive plants.
How does Osmocote’s Smart‑Release technology differ from standard slow‑release formulas?
Osmocote coats each granule with a resin that regulates nutrient release for up to six months, providing a very steady feed. Traditional slow‑release products, like the 10‑10‑10 blends, rely on granule size and composition for a shorter 8‑week feeding window.
Which product gives the best value for large lawns?
The Slow Release Lawn Fertilizer 25‑5‑10 (65 % nitrogen) covers up to 110 days and is priced for bulk use, making it cost‑effective for expansive lawns. Osmocote’s 8‑lb container also offers good coverage (300 sq ft) but at a higher per‑pound price.
Are organic options like Organic Plant Magic comparable to synthetic 10‑10‑10 fertilizers?
Organic Plant Magic provides a full spectrum of nutrients plus trace minerals and beneficial microbes, which can improve soil health over time. Synthetic 10‑10‑10 formulas deliver precise N‑P‑K ratios and faster results, but lack the organic matter benefits.
What is the advantage of a balanced 10‑10‑10 blend versus a high‑nitrogen mix?
A 10‑10‑10 blend supplies equal parts nitrogen, phosphorus, and potassium, supporting overall plant vigor, root development, and bloom production. High‑nitrogen mixes like 25‑5‑10 boost rapid leaf growth but may require supplemental phosphorus and potassium for flowering or fruiting.
How do I determine the right coverage amount for my garden?
Check each product’s label for square‑foot coverage per pound and calculate based on your garden’s total area. For example, Osmocote’s 2‑lb bag covers about 75 sq ft, while the 10‑10‑10 5‑lb bag typically treats 200‑250 sq ft depending on soil type.
Is there a safety concern with using slow‑release fertilizers around pets and children?
Most slow‑release granules are low‑dust and safe when applied as directed, but it’s wise to keep pets and kids off freshly spread areas until the granules are watered in. Products that advertise a “no‑burn pledge,” like Osmocote, often include extra safety assurances.