Comparison: Best Costco Miracle Gro Soil (Updated | Nov 11th)
If you’ve ever stood in the gardening aisle wondering which bag of Miracle-Gro soil at Costco is truly worth your hard-earned cash, you’re not alone. We’ve dug into the details—literally—to compare the top picks, weighing value, quality, and real garden results. Whether you’re potting herbs on a balcony or reviving a backyard oasis, we’ll help you choose the best Costco Miracle-Gro soil without the guesswork. Let’s get your garden thriving the smart way.
- Best for six-month growth: Miracle-Gro Potting Mix
- Best for organic quick-release: Miracle-Gro Organic Outdoor Potting Mix
- Best for moisture guard: Miracle-Gro Moisture Control Potting Mix
- Best for gnats-resistant indoor: Miracle-Gro Houseplant Potting Mix: Fertilized
- Best for dual bag indoor: Miracle-Gro Houseplant Potting Mix – Fertilized Soil
- Best for all-season moisture: Miracle-Gro Moisture Control Potting Mix for Outdoor and Indoor Plants
- Best for coir indoor blend: Miracle-Gro Indoor Potting Mix
- Best for color-boost mix: Miracle-Gro Potting Mix
- Best for bulk organic mix: Miracle-Gro Organic Outdoor Potting Mix
- Best for fast-drain succulents: Miracle-Gro Cactus
Product Comparison: Best Costco Miracle Gro 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 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 Houseplant Potting Mix – Fertilized Soil, Designed to be Less Prone to Gnats, 4 qt. (2-Pack)
- Growing indoors is easy under the right conditions; Miracle-Gro Houseplant Potting Mix combines key elements plants need to thrive
- This indoor plant soil is less prone to gnats thanks to the combination of perlite, sphagnum and peat moss
- Recommended for growing beautiful, indoor houseplant varieties like pothos, spider plants, monstera, philodendron, english ivy, and more
- Certified by the Mulch & Soil Council as in compliance with industry standards
- Bundle includes two bags of Miracle-Gro Houseplant Potting Mix
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 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 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 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)
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)
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 between the regular, organic, and moisture‑control potting mixes?
Consider the plant type, watering habits, and whether you prefer synthetic or natural fertilizers. The regular mix feeds for up to six months and is great for general container gardening, while the organic mix uses a quick‑release natural fertilizer and is certified responsibly sourced. Moisture‑control mix adds an AquaCoir formula that absorbs 33% more water, helping prevent over‑ or under‑watering.
How does the Moisture Control Potting Mix differ from the standard Miracle‑Gro mix?
Moisture Control contains coir, sphagnum peat moss, and a wetting agent that lets the soil hold up to a third more water than basic mixes. It also feeds plants for six months and includes a protective layer against both over‑ and under‑watering. The standard mix lacks these water‑retention additives but still provides six‑month feeding and promotes larger growth.
Can I use the Organic Outdoor Potting Mix for indoor houseplants?
Yes, the organic mix can be used indoors, but it’s formulated for outdoor containers and feeds for only two months. If you want longer feeding and a blend designed to reduce fungus gnats, the indoor‑specific mixes are a better choice. The organic option is ideal if you prioritize natural, certified peat and a quick‑release fertilizer.
How much potting mix do I need for a 12‑inch container?
A 16‑quart bag of the standard, organic, or indoor potting mixes typically fills one 12‑inch container, though the exact amount can vary with root ball size. The 8‑quart bags of Moisture Control fill two 8‑inch containers, so you’d need roughly two of those for a 12‑inch pot. For larger projects, the 25‑quart organic bag can cover three 10‑inch containers.
Which mix is best for preventing fungus gnats on houseplants?
The Houseplant Potting Mixes (both single‑bag and two‑bag bundles) are formulated without compost or bark, which are common gnats habitats, and include perlite and sphagnum peat for better drainage. The Indoor Potting Mix also emphasizes a low‑gnat formula with coconut coir. These options are preferable to the standard or organic mixes for indoor pest control.
How long does the built‑in fertilizer last in each product?
The regular, Moisture Control, and indoor potting mixes feed plants for up to six months, providing sustained nutrition. The organic outdoor mix offers a quick‑release natural fertilizer that lasts about two months. The houseplant mixes also provide up to six months of feeding, supporting continuous growth.
Is the 25‑quart Organic Outdoor Potting Mix a better value than the 16‑quart bags?
The larger 25‑quart bag fills roughly three 10‑inch containers and usually has a lower price per quart, making it cost‑effective for bigger gardening projects. However, if you only need to fill a few smaller pots, the 16‑quart bags may be more convenient and easier to store. Consider both the volume you need and storage space when evaluating value.
Can the Cactus, Palm & Citrus Mix be used for regular vegetable gardening?
While the Cactus, Palm & Citrus Mix is fast‑draining and enriched with plant food, it’s optimized for succulents, palms, and citrus trees that prefer drier conditions. Vegetables generally thrive in a richer, moisture‑retentive mix like the standard or indoor potting soils. Using the cactus mix for vegetables may require more frequent watering and supplemental fertilization.