Best Natural Fertilizer For Plants for Indoor and Outdoor Growing

#1 · Best Overall

1. Back to the Roots All-Purpose Plant Food

• Weight: 5 lb

Best for: Plant-based all-purpose blend.

Why it ranks #1: Its plant- and mineral-based blend suits broad all-purpose feeding and includes kelp, alfalfa meal, mycorrhizae, and rock phosphate.

A 100% plant- and mineral-based formulation gives Back to the Roots All-Purpose Plant Food a clear fit for gardeners avoiding synthetic chemicals and factory-farmed animal waste. Kelp, alfalfa meal, mycorrhizae, and rock phosphate combine broad nutrition with a root-growth focus in one five-pound blend.

The five-pound size supports ongoing feeding, while the directions call for mixing one tablespoon with a gallon of water and applying every two to four weeks. That recurring liquid application can fit a broad range of plants, including herbs, flowers, and fruiting plants mentioned in the description. Kelp and alfalfa meal provide long-lasting nutrition, and mycorrhizae are included to promote strong root growth; wear gloves when handling and keep the product away from children and pets.

Skip it if you prefer ready-to-use liquid fertilizer; Purived 16oz All-Purpose Liquid Plant Fertilizer mixes by capful into water.

This is a fit for gardeners seeking a plant- and mineral-based all-purpose blend who can mix a fresh watering solution every two to four weeks. Its powder form calls for preparation rather than direct liquid dosing.

Listed on Amazon as: Back to The Roots Organic All-Purpose Plant Food (5 lb. Value Size), Premium Blend, Safe & Sustainable Vegan Formulation Made with Kelp and Alfaalfa Meal, Mycorrhize, and Rock Phosphate Minerals

#2 · Best Slow-Release Granules

2. Espoma Plant-Tone

• Weight: 4 lb
• Form: Granules

Best for: Slow-release mixed planting beds.

Why it ranks #2: This 5-3-3 granular food serves flowers, vegetables, trees, and shrubs, with natural ingredients that break down slowly.

Espoma Plant-tone’s natural ingredients break down slowly, creating a long-lasting nutrient reservoir for gardeners who want fewer quick-feed applications. The 5-3-3 granular formula is listed for flowers, vegetables, trees, and shrubs, making it a broad option for mixed outdoor plantings and perennial landscaping.

Plant-tone’s granular form is suited to soil application, and its slow breakdown supports a longer-lasting supply of nutrients rather than a liquid dose with each watering. The listed uses span annuals, perennials, roses, vegetables, trees, and shrubs, so one bag can serve varied garden areas. Directions specify spring and fall use on trees and shrubs, giving those plantings a seasonal schedule. The four-pound bag is a manageable size for home gardens, though handling precautions call for protective equipment.

Skip it if you want a liquid fertilizer for a watering routine; Grow Queen Organic Liquid Indoor Plant Food mixes directly into water.

Gardeners tending mixed flower beds, vegetables, trees, and shrubs can use Plant-tone as a slow-breaking granular feed. Its seasonal tree-and-shrub directions and handling precautions suit planned soil applications, not liquid dosing.

Listed on Amazon as: Espoma Organic Plant-Tone 5-3-3 Natural & Organic All Purpose Plant Food; 4 lb. Bag; The Original Organic Fertilizer for All Flowers, Vegetables, Trees, and Shrubs.

#3 · Best Balanced Blend

3. True Organic All Purpose Plant Food

• Weight: 4 lb
• Form: Granules

Best for: Balanced organic garden coverage.

Why it ranks #3: Its 5-4-5 NPK profile also supplies calcium and sulfur, and it is formulated for fruits, vegetables, flowers, herbs, and foliage.

A listed 87-square-foot coverage area makes True Organic All Purpose Plant Food easy to match to a defined garden footprint. Its balanced formula is intended for fruits, vegetables, flowers, herbs, and foliage, while the four-pound granular bag suits gardeners applying fertilizer directly to soil.

The formula lists 5% nitrogen, including 3.75% slow-release nitrogen, alongside 4% phosphate, 5% potash, 4% calcium, and 1% sulfur. That nutrient detail helps gardeners assess its broad feeding profile, while the slow-release nitrogen supports a more gradual portion of the supply. Its organic blend includes seabird guano, shrimp and crab shell meal, soybean meal, and fish bone meal. The stated 87-square-foot coverage gives a planning reference for garden application, rather than a capful-based liquid routine.

Skip it if you want liquid fertilizer for indoor potted plants; Purived 16oz All-Purpose Liquid Plant Fertilizer is listed for indoor and outdoor pots.

Gardeners covering a defined soil area with a broad organic fertilizer can use this four-pound granular blend across edible and ornamental plants. Its soil-oriented format is not the natural fit for liquid, watering-time feeding.

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

#4 · Best Water-Soluble Powder

4. Organic Plant Magic Fertilizer

• Weight: 8 oz
• Form: Powder

Best for: One concentrate for mixed gardens.

Why it ranks #4: One half-pound bag makes 32 or more gallons and is described for vegetables, flowers, herbs, fruit, trees, gardens, and houseplants.

One half-pound bag makes more than 32 gallons of liquid plant food, giving Organic Plant Magic buyers a concentrated option for feeding houseplants and outdoor gardens from the same product. Its all-purpose scope includes vegetables, flowers, herbs, fruit, trees, and garden plants, reducing the need for separate formulas.

The water-soluble powder becomes a liquid feed when mixed, which lets one product serve indoor pots and outdoor plantings. Its stated coverage of 32-plus gallons from a half-pound bag supports repeated use across a mixed collection, while the listed rapid-release and slow-release options point to different feeding rhythms. The product also claims to expand four times with water. Follow the directions and store it below 120 degrees for the stated optimal performance.

Skip it if you want a ready-to-use liquid with a stated capful-per-gallon dose; Purived 16oz All-Purpose Liquid Plant Fertilizer offers that format.

Gardeners managing houseplants alongside vegetables, flowers, or trees may value one concentrate for varied plantings. This powdered product suits people willing to mix it with water rather than keep a ready-to-pour liquid on hand.

Listed on Amazon as: Organic Plant Magic Fertilizer & Plant Food for House Plants & Garden 1/2lb

#5 · Best Vegetable Formula

5. Down to Earth Vegetable Garden

• Weight: 5 lb
• Form: Granules

Best for: Slow-release vegetable beds.

Why it ranks #5: Its 4-4-4 slow-release granules are tailored to vegetables, herbs, greens, and raised beds, with directions for soil-bed application.

A slow-release 4-4-4 formula gives Down to Earth’s vegetable-garden fertilizer a balanced granular option for feeding soil gradually. Its listed uses include vegetables, herbs, greens, and raised beds, while the five-pound box can be applied directly to soil or mixed into garden beds.

For spring starts, directions call for preparing the soil, distributing the fertilizer evenly, and mixing it into the topsoil. Summer tomatoes receive an application around the plant base without touching the stem, while herbs have their own listed guidance. That soil-first workflow fits gardeners preparing beds or tending established vegetable plantings. The gradual-release formula is described as providing long-lasting support and reducing nutrient leaching; the product is also listed as safe for beneficial insects, pollinators, pets, and the surrounding ecosystem.

Skip it if you want a concentrated liquid for watering indoor pots; Purived 16oz All-Purpose Liquid Plant Fertilizer is listed for potted plants and liquid feeding methods.

Raised-bed and vegetable gardeners who prepare soil or side-dress tomato plants can use this gradual-release granular feed. Its soil-application workflow is less suitable for indoor growers who prefer dosing fertilizer with water.

Listed on Amazon as: Down to Earth All Natural Fertilizers Organic Vegetable Garden – Plant Food for Vegetables, Herbs, Greens and Raised Beds 4-4-4, 5 lb

#6

6. Dr. Earth Organic 5

• Weight: 4 lb
• Form: Granules

Best for: Organic vegetable-bed granules.

Why it ranks #6: This organic granular formula targets tomatoes, vegetables, and herbs, feeds for several months, and includes beneficial soil microbes.

Beneficial soil microbes and mycorrhizae distinguish Dr. Earth Organic 5 for tomato, vegetable, and herb gardens. The granular blend is intended to feed for several months, giving gardeners a longer-running soil application for beds, containers, and planting rather than a liquid feed added with each watering.

The product combines seven champion strains of beneficial soil microbes with ecto- and endo-mycorrhizae, making it a fit for gardeners seeking a microbe-enriched fertilizer. Its granules can be used in organic vegetable gardens, raised beds, containers, or native backyard soil, and the directions also allow making compost tea. The listed guidance calls for application as directed; the several-month feeding claim may suit gardeners who prefer a longer interval between feedings over repeated watering-time doses.

Skip it if you want a liquid fertilizer to measure into every watering; Grow Queen Organic Liquid Indoor Plant Food is a liquid concentrate.

Choose this granular formula for vegetable gardeners who want organic inputs and microbe-focused soil feeding across beds or containers. Its granule form and application directions are less convenient for anyone seeking a liquid watering routine.

Listed on Amazon as: Dr. Earth Organic 5 Tomato, Vegetable & Herb Fertilizer Poly Bag

#7

7. Grow Queen Indoor Plant Food

• Weight: 0.36 kg
• Form: Liquid

Best for: Indoor liquid-feeding routine.

Why it ranks #7: Its balanced 5-5-5 liquid is made for indoor plants, houseplants, and tropicals; the 8-ounce bottle treats up to 50 gallons.

A balanced 5-5-5 liquid formula lets indoor plant owners add equal nitrogen, phosphorus, and potassium right into routine watering. Grow Queen’s concentrate is intended for houseplants and tropicals, and its capful-per-gallon direction makes it a practical choice for growers who prefer feeding while they water.

The 8-ounce bottle treats up to 50 gallons, so a small measured amount can support repeated indoor feedings. Mix about one 4 ml capful per gallon of water, then use it during watering; that liquid workflow suits potted plants without requiring a separate granular application. Its 5-5-5 balance is described for use at every watering, while the formula includes sea kelp. Keep it away from children and pets, and do not apply it to food crops intended for consumption.

Skip it if you need fertilizer for edible crops; this product says not to apply it to food crops intended for consumption.

Indoor growers who want to combine feeding with watering can use this concentrated liquid for houseplants and tropicals. Its stated food-crop restriction makes it a poor match for plants grown for human or animal consumption.

Listed on Amazon as: Organic Liquid Indoor Plant Food, Houseplant, Tropical & All-Purpose Indoor Plant Fertilizer, Organic Liquid Fertilizer 5-5-5 with Sea Kelp, 8oz Treats 50 Gallons

#8

8. Purived Liquid Plant Fertilizer

• Weight: 16 oz
• Form: Liquid

Best for: Multi-method liquid feeding.

Why it ranks #8: This all-purpose liquid works for indoor and outdoor potted plants and supports soil drench, foliar, and hydroponic feeding methods.

Compatibility with soil drenching, foliar feeding, and full or semi hydroponics sets Purived apart for growers who use more than one feeding method. This odorless, all-purpose liquid is intended for indoor and outdoor potted plants, with a capful mixed into a gallon of water for feeding.

The 16-ounce bottle makes 50 gallons, and its capful-per-gallon direction gives growers a simple way to prepare each feeding. The formula is listed for soil drench, foliar, and full or semi hydroponic methods, so one product can suit varied potted-plant setups. Its two-year shelf life is useful for keeping a bottle between applications, while the odorless claim may appeal in indoor spaces. It is made in the USA and described as groundwater safe.

Skip it if you need fertilizer specifically listed for vegetable beds and raised beds; Down to Earth 4-4-4 Organic Vegetable Garden is made for those uses.

Choose Purived if you care for potted plants across soil, foliar, or hydroponic feeding methods and want a concentrated liquid. The listing focuses on potted plants, so garden-bed growers should consider a bed-specific option.

Listed on Amazon as: Purived 16oz All-Purpose Liquid Plant Fertilizer – Makes 50 Gallons, for Indoor Houseplants, All-Natural, Groundwater Safe, Made in USA

#9

9. FoxFarm Big Bloom

• Weight: 16 oz
• Form: Liquid

Best for: Flowering and fruiting support.

Why it ranks #9: Earthworm castings and bat guano support flowering and fruiting plants, but its 0-0.5-0.7 NPK profile is less general-purpose.

Earthworm castings and bat guano give FoxFarm Big Bloom its defining natural nutrient blend for flowering and fruiting plants. The liquid fertilizer is described for every growth stage, with quick nutrient absorption intended to make its nutrients available promptly as plants move through growth and bloom.

Big Bloom is a liquid with a 0-0.5-0.7 NPK listing, so buyers can evaluate its nutrient profile alongside its stated focus on flowering and fruiting. Its earthworm castings and bat guano provide the natural-ingredient basis, while the immediate-uptake claim supports growers seeking a liquid feed rather than a slow-release granular product. The listing also notes that phosphorus runoff can threaten water quality and that some states restrict phosphorus fertilizers on non-agricultural lawns or turf.

Skip it if you need a granular, slow-release garden feed; Espoma Organic Plant-Tone is a granular option with slowly released nutrients.

Flower and fruit growers who prefer a liquid blend with earthworm castings and bat guano may find this format suitable. Check local rules before using it on non-agricultural lawns or turf because it contains phosphorus.

Listed on Amazon as: Fox Farm Big Bloom Liquid Plant Food – Organic Bloom Fertilizer for Flowering & Fruiting Plants, Contains Earthworm Castings & Bat Guano – Supports All Stages of Plant Growth – 0-0.5-0.7 NPK, 1 Pint

#10

10. Farmer’s Secret Fruit & Bloom Booster

• Weight: 1.4 lb
• Form: Liquid

Best for: Fruit and bloom concentrate.

Why it ranks #10: Its concentrated liquid targets fruit, vegetables, and flowers, with high phosphorus and potassium that make it less suitable for general feeding.

A super-concentrated formula high in phosphorus and potassium targets growers focused on fruit and bloom production. Farmer’s Secret Fruit & Bloom Booster is intended for fruit-, vegetable-, and flower-producing plants, with root-strengthening support described as a way to improve nutrient uptake and encourage flowering or yield.

The liquid concentrate is diluted with water and applied by pouring or spraying during a plant’s regular watering routine every two to four weeks. That schedule lets growers fold the booster into established care without switching to a separate watering method. Its phosphorus and potassium emphasis is specifically linked in the listing to bloom and fruit production, while the stated range includes examples such as citrus, avocados, raspberries, roses, and petunias. It is not presented as an all-purpose indoor-potted formula.

Skip it if you need one fertilizer for general indoor potted plants; Purived 16oz All-Purpose Liquid Plant Fertilizer is listed for indoor and outdoor potted plants.

Fruit, vegetable, and flower growers seeking a concentrated booster can work it into regular watering every two to four weeks. Its targeted fruit-and-bloom purpose is a boundary for buyers seeking broad foliage feeding.

Listed on Amazon as: Farmer’s Secret Fruit & Bloom Booster Fertilizer – Super Concentrated – Boosts Flowering and Yield on All Varieties of Fruits, Vegetables and Flowers (16oz)