Comparison: Best Costco Miracle Grow Potting Soil (Updated | Nov 11th)
At Costco, two heavyweights go head-to-head: Miracle-Gro’s popular mixes promise big results, but which one delivers the best value and performance? We’ve dug into the details—ingredients, price per cubic foot, and real garden results—to help you choose the right bag without wasting money or guesswork.
- Best for all-purpose growth: Miracle-Gro Potting Mix
- Best for organic quick-release: Miracle-Gro Organic Outdoor Potting Mix
- Best for moisture control: Miracle-Gro Moisture Control Potting Mix
- Best for versatile moisture mix: Miracle-Gro Moisture Control Potting Mix for Outdoor and Indoor Plants
- Best for vibrant growth mix: Miracle-Gro Potting Mix
- Best for gnat-resistant indoor: Miracle-Gro Indoor Potting Mix
- Best for houseplant perlite blend: Miracle-Gro Houseplant Potting Mix: Fertilized
- Best for fast-drain succulent: Miracle-Gro Cactus
- Best for large-scale flourish: Miracle-Gro 2 Pack Potting Soil Mix for Container Plants
- Best for bulk organic mix: Miracle-Gro Organic Outdoor Potting Mix
Product Comparison: Best Costco Miracle Grow Potting Soil
Miracle-Gro Potting Mix, For Container Plants, Flowers, Vegetables, Annuals, Perennials, Shrubs, Feeds for up to 6 Months, 16. qt., 2-Pack
- Miracle-Gro Potting Mix feeds container plants for up to 6 months so you get more blooms for more color (vs. unfed plants)
- How to use: To use this potting medium, fill a container about 1/3 full with potting mix, place your plant in the soil, and fill the rest of the pot, pressing lightly
- What’s included: This bundles includes two 16 qt. bags of Miracle-Gro Potting Mix, each able to fill one 12-inch container (exact amounts may vary based on root ball size)
- Where to Use: Use this home gardening product with all types of container plants, including annual and perennial flowers, vegetables, herbs and shrubs
- This potting soil mix Grows Plants Twice As Big (vs. unfed plants)
Miracle-Gro Organic Outdoor Potting Mix, for Outdoor Container Plants, Contains Quick-Release Natural Fertilizer, OMRI Listed, 16 qt.
- Miracle-Gro Organic Outdoor Potting Mix contains a quick-release natural fertilizer and also feeds plants for up to 2 months
- This potting mix is made with responsibly sourced peat (one hundred percent of peat sourced from certified producers)
- Use this organic potting mix with all types of outdoor container plants, including flowers, vegetables, herbs, annuals, and perennials
- To plant in pots, fill the container partially full with potting mix, place the plant in the pot after loosening the root ball, cover with more mix and water thoroughly
- One 16 qt. bag of Miracle-Gro Organic Outdoor Potting Mix fills one 12-inch container (amounts may vary based on the size of the root ball)
Miracle-Gro Moisture Control Potting Mix, For Container Plants, Protects against Over- and Under-Watering, 8 qt., 2-Pack
- Miracle-Gro Moisture Control Potting Mix feeds plants for up to 6 months and Grows Plants Twice As Big! (vs unfed plants)
- This potting medium protects against over and under watering; also absorbs up to 33% more water than basic potting soil* with exclusive AquaCoir Formula (*soil that does not contain sphagnum peat moss, coir, and wetting agent)
- Use this gardening product with all types of container plants, including flowers, vegetables, annuals, perennials, and shrubs
- To use this potting soil, fill a container about 1/3 full with potting mix; place your plant in the pot and cover with more mix
- This bundle comes with two 8 qt. bags of Miracle-Gro Moisture Control Potting Mix; each fills two 8-inch containers (exact amounts may vary depending on the size of the root ball)
Miracle-Gro Moisture Control Potting Mix for Outdoor and Indoor Plants, 1 cu. ft. 2-pack
- Protects against over- and under-watering
- Feeds up to 6 months
- Grows Plants Twice as Big! *vs. unfed plants
- Absorbs up to 33% more water than basic potting soil* *vs. potting soil that does not contain sphagnum peat moss, coir and wetting agent
- Helps beautify potted flowers, indoors and out
Miracle-Gro Potting Mix, For Indoor or Outdoor Potted Plants, Flowers, Vegetables, Shrubs, Annuals, and Perennials, Feeds Up to 6 Months, 8 qt.
- Feeds all potted plants: Miracle-Gro Potting Mix feeds all types of potted plants, including flowers, vegetables, shrubs, annuals, and perennials for up to 6 months
- Promotes growth: This potting soil Grows Plants Twice As Big! (vs. unfed plants)
- Boosts color: Get more blooms for more color (vs unfed plants)
- Application: To apply this potting medium, fill a container about 1/3 full with potting mix, place your plant in the soil, and fill the rest of the pot, pressing lightly; water thoroughly
- Coverage: Each 8 qt. bag of Miracle-Gro Potting Mix fills two 8 inch containers (exact amounts may vary depending on the size of the root ball)
Miracle-Gro Indoor Potting Mix, Blended for a Variety of Houseplants, Feeds for up to 6 Months, 16 qt., 2-Pack
- Miracle-Gro Indoor Potting Mix feeds houseplants for up to 6 months and is designed to be less prone to gnats (contains no compost or bark, which are known to shelter fungus gnats)
- This potting mix contains coconut coir, which holds and releases water and helps soil re-wet
- Where to use: Blended for a wide variety of indoor container plants, including climbing, foliage, flowering, and tropical plants
- How to use: To use, fill a container about 1/3 full with potting mix; add more mix after placing your plant in the pot
- What’s included: This bundles includes two 16 qt. bags of Miracle-Gro Indoor Potting Mix, each able to fill one 12-inch containers (exact amount may vary based on the root ball size)
Miracle-Gro Houseplant Potting Mix: Fertilized, Perlite Soil for Indoor Gardening, Designed to Be Less Prone to Gnats, 4 qt.
- Growing indoors is easy under the right conditions; Miracle-Gro Houseplant Potting Mix combines key elements plants need to thrive
- Recommended for growing beautiful indoor houseplant varieties like Pothos, Spider Plants, Monstera, Philodendron, English Ivy and more
- This indoor plant soil is less prone to gnats, thanks to the combination of perlite, sphagnum and peat moss that’s just right
- Certified by the Mulch & Soil Council as a quality product in compliance with industry standards
- A single 4-qt bag fills an 8-inch container; for even more spectacular results, start regular feedings with Miracle-Gro Plant Food 30 days after planting
Miracle-Gro Cactus, Palm and Citrus Potting Mix, for Indoor or Outdoor Potted Plants, Great for Succulents, 8 qt., 2-Pack
- Miracle-Gro Cactus, Palm & Citrus Potting Mix features a fast-draining formula and is enriched with Miracle-Gro Plant Food
- This fast-draining formula is blended to help promote successful growing of cacti, potted palms, citrus, and other succulents
- This cactus potting mix is designed for indoor and outdoor container plants, including cacti, palm plants, citrus trees, and succulents
- To use this succulent soil mix, fill a pot with a drainage hole 1/3 full of mix, top with more mix after placing plant, and press lightly
- This bundle includes two 8 qt. bags of Miracle-Gro Cactus, Palm & Citrus Potting Mix, each able to fill two 8-inch containers (amounts may vary based on root ball size)
Miracle-Gro 2 Pack Potting Soil Mix for Container Plants, Flowers, Vegetables, Shrubs, Annuals, and Perennials, Feeds for Up to 6 Months, 2 Cu Ft
- BIGGER PLANTS: Watch your container plants flourish with this potting soil that feed for up to 6 months to grow plants twice as big versus unfed plants
- VIBRANT COLORS: Get ready for a spectacular show of more blooms for more color versus unfed plants transforming your containers into dazzling displays
- WHERE TO USE: Perfect for all indoor or outdoor grown containers plants, including flowers, vegetables, herbs, and houseplants
- HOW TO USE: Pick a pot with drainage, fill it 1/3 full with this ready-to-use container mix, add your plant and fill in with more soil, then water; it’s that easy to create beautiful container gardens
- COVERAGE: Each 2 cu. ft. bag of Miracle-Gro Potting Mix fills two 14-inch containers (actual amount may vary depending on the size of the root ball)
Miracle-Gro Organic Outdoor Potting Mix, for Outdoor Container Plants, Contains Quick-Release Natural Fertilizer, OMRI Listed, 25 qt.
- Miracle-Gro Organic Outdoor Potting Mix contains a quick-release natural fertilizer and also feeds plants for up to 2 months
- This potting mix is made with responsibly sourced peat (one hundred percent of peat sourced from certified producers)
- Use this organic potting mix with all types of outdoor container plants, including flowers, vegetables, herbs, annuals, and perennials
- To plant in pots, fill the container partially full with potting mix, place the plant in the pot after loosening the root ball, cover with more mix and water thoroughly
- One 25 qt. bag of Miracle-Gro Organic Outdoor Potting Mix fills three 10-inch containers (amount may vary based on the size of the root ball)
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 are the main differences between the standard Miracle‑Gro Potting Mix and the Organic Outdoor Potting Mix?
The standard mix contains a synthetic, quick‑release fertilizer that feeds plants for up to six months, while the Organic Outdoor mix uses a natural, quick‑release fertilizer lasting about two months. The organic version also emphasizes responsibly sourced peat, making it a greener choice for environmentally conscious gardeners.
When should I choose the Moisture Control Potting Mix over the regular mix?
Moisture Control Mix includes the AquaCoir formula that absorbs up to 33% more water and helps prevent over‑ or under‑watering, which is ideal for plants that sit in fluctuating indoor climates. If you prefer a set‑and‑forget approach and want to reduce watering frequency, this mix offers added convenience.
Is the Indoor Potting Mix better for houseplants than the regular potting soil?
Yes, the Indoor Mix is formulated without compost or bark, reducing the risk of fungus gnats, and it contains coconut coir for steady moisture release. These features make it especially suited for foliage and tropical houseplants that thrive in a clean, well‑drained environment.
How do I decide how much potting mix I need for my containers?
Most product listings note coverage: a 16‑qt bag typically fills one 12‑inch pot, while an 8‑qt bag covers two 8‑inch containers. For larger planters, calculate the volume in cubic feet; a 2‑cu ft bag can fill two 14‑inch pots, helping you avoid buying excess material.
What value does the 2‑Pack Potting Soil Mix provide compared to buying single bags?
The 2‑Pack offers a larger total volume (2 cu ft) at a lower per‑cubic‑foot price, making it cost‑effective for gardeners planning multiple containers or larger beds. It also includes the same six‑month feeding guarantee, delivering consistent growth without additional fertilizer purchases.
Can I use the Cactus, Palm & Citrus Mix for regular flower containers?
While the Cactus, Palm & Citrus Mix is optimized for fast‑draining conditions ideal for succulents, it can be used for other plants that prefer well‑aerated soil. However, flowering annuals may benefit more from the standard or moisture‑control mixes that retain extra moisture and nutrients.
Is there a noticeable growth advantage with Miracle‑Gro mixes that claim “twice as big”?
The “twice as big” claim is based on controlled tests comparing fed plants to unfed controls; users typically see larger foliage and more vigorous blooms when using the fertilized mixes. Real‑world results vary with plant type, light, and watering practices, but most gardeners report a noticeable boost.
What should I look for on the label to ensure the potting mix matches my gardening needs?
Check the feeding duration (e.g., up to six months vs. two months), moisture‑control features, and intended use (indoor, outdoor, cactus, organic). Also verify coverage information and any certifications, such as responsibly sourced peat, to align the product with your specific planting conditions and sustainability preferences.