5 Best Compost Starters - May 2026

Biomaster Compost-It Compost Accelerator

A top-selling compost starter — for good reason. Contains quality active ingredients and works well while controlling odors.

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PROS

Packed with nutrients that turn lawn and kitchen waste to compost in as little as four weeks.
Reduces odor and works wherever compost is made: piles, tumblers, bins, and more.
Made of natural, organic ingredients with 60-plus microbe strains.

CONS

Package is on the small side, so you may need more than one for large compost systems.
Pricey.

BEST BANG FOR THE BUCK

Jobe's Organics

Compost Starter Microbe Additive

Trusted Brand

Reasonably priced compost starter by a popular brand in lawn care products.

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PROS

Made with Jobe's proprietary blend of microorganisms and certified organic materials that are formulated to speed up composting times.
Enhances soil.
Decent price.
Available in choice of three bag sizes.

CONS

Has a strong odor, and doesn't control composting odors well.
Doesn't speed up composting time for some waste materials.

Roebic

Compos Accelerator

Simple Yet Solid

This quality compost starter is natural and works at speeding up the composting process for most waste materials, but not all.

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PROS

Speeds up composting times while maintaining a pH balance that promotes healthy soil that's rich in nutrients.
Natural formula works fast for most materials and helps break down waste like lawn clippings, leaves, and more.
Controls odors.

CONS

May take longer than expected to turn some waste items into compost.

GREEN PIG

Compost Accelerator

Easiest to Use

Accelerates the composting process with bacteria that are effective at keeping odors under control while they work.

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PROS

Bacteria-based formula is effective at turning many waste items into compost.
Individual packets are convenient and easy to use.
Does a good job controlling odors while compost forms.

CONS

Company's claim of producing compost in as few as 30 days is questionable.
Not very effective for large piles.

SCD Probiotics

Compost Starter and Microbial Inoculant

Affordable and Natural

Simple, natural product that accelerates composting, but may not work as quickly as you'd like.

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PROS

Contains natural microbes that turn just about any type of waste into compost.
Produces low oxygen levels while turning waste to compost.
Suitable for indoor composting.
Easy to use.
Decent price.

CONS

Somewhat smelly.
Has the tendency to take longer than anticipated to break down some materials.

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BestReviews spends thousands of hours researching, analyzing, and testing products to recommend the best picks for most consumers. We buy all products with our own funds, and we never accept free products from manufacturers.About BestReviews

How We Tested

We recommend these products based on an intensive research process that's designed to cut through the noise and find the top products in this space. Guided by experts, we spend hours looking into the factors that matter, to bring you these selections.

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First Reviewed

May 07, 2021

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