Comparison: Best Costco Soil Miracle Gro (Updated | Nov 11th)
If you’ve ever stood in the garden aisle wondering whether Costco’s bulk soil is worth it or if Miracle-Gro is the real deal, you’re not alone. After testing both side by side in our own gardens, we’re spilling the dirt—literally—on which one delivers better value, texture, and results. Spoiler: it’s not always the pricier option. Let’s dig into what actually works so you can grow with confidence.
- Best for eco outdoor boost: Miracle-Gro Organic Outdoor Potting Mix
- Best for long-lasting growth: Miracle-Gro Potting Mix
- Best for moisture master mix: Miracle-Gro Moisture Control Potting Mix
- Best for gnat-resistant indoor: Miracle-Gro Houseplant Potting Mix: Fertilized
- Best for vibrant dual-use: Miracle-Gro Potting Mix
- Best for indoor gnat guard: Miracle-Gro Houseplant Potting Mix – Fertilized Soil
- Best for coir water retention: Miracle-Gro Indoor Potting Mix
- Best for bulk eco outdoor: Miracle-Gro Organic Outdoor Potting Mix
- Best for big bloom duo: Miracle-Gro 2 Pack Potting Soil Mix for Container Plants
- Best for fast-drain succulents: Miracle-Gro Cactus
Product Comparison: Best Costco Soil Miracle Gro
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 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 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 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 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 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 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 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 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 are the key differences between the organic outdoor mixes and the standard Miracle‑Gro potting mixes?
The organic outdoor mixes (e.g., the 16‑qt and 25‑qt bags) contain a quick‑release natural fertilizer and are made with responsibly sourced peat, feeding plants for up to two months. Standard mixes use synthetic fertilizer and promise up to six months of feeding, often delivering faster growth and larger blooms. Choose organic if you prefer natural nutrients and a shorter feeding window; choose standard for longer‑lasting fertilizer power.
Which Miracle‑Gro mix is best for indoor houseplants that are prone to fungus gnats?
The Houseplant Potting Mixes (4‑qt, 2‑bag, and the indoor‑focused blend) are formulated with perlite, sphagnum, and peat to reduce gnat habitats, and they contain no compost or bark. They also include a light fertilizer that lasts about six months. These mixes are ideal for foliage‑heavy houseplants like pothos, monstera, and spider plant.
How does the Moisture Control Potting Mix differ from regular potting soil?
Moisture Control uses an AquaCoir formula that absorbs up to 33 % more water than basic mixes and helps prevent both over‑ and under‑watering. It does not contain sphagnum peat moss, relying on coir and a wetting agent for consistent moisture release. This mix is useful for gardeners who want a more forgiving watering schedule.
If I have a 12‑inch outdoor container, which bag size gives the best coverage and value?
A 16‑qt bag of the standard Miracle‑Gro Potting Mix or the Indoor Potting Mix typically fills one 12‑inch container, while the 25‑qt Organic Outdoor Mix can fill three 10‑inch containers, offering a lower cost per cubic foot. For the best value, compare the price per cubic foot; larger bags usually reduce the per‑bag cost, especially when purchased at Costco.
Can I use the same mix for both vegetables and ornamental flowers?
Yes, most Miracle‑Gro mixes—including the standard, organic outdoor, and indoor blends—are labeled for “all types of container plants,” covering vegetables, herbs, annuals, perennials, and flowering plants. The fertilizer ratios are balanced to support both edible and ornamental growth, though you may want a higher‑nutrient mix for heavy‑feeding vegetables.
What should I look for when comparing bundle sizes versus single bags?
Bundles (e.g., two 16‑qt bags) often provide a lower price per quart and ensure you have enough mix for multiple containers, while single bags are convenient for a single project or limited storage space. Check the coverage claims—most bundles state how many 8‑inch or 12‑inch pots they fill—to match the number of containers you plan to fill.
Is there a specific Miracle‑Gro mix recommended for cacti, palms, or citrus trees?
The Cactus, Palm & Citrus Potting Mix is a fast‑draining formula enriched with Miracle‑Gro Plant Food, designed for succulents, palms, and citrus. Its quick‑drainage helps prevent root rot in plants that prefer drier conditions. This mix comes in two 8‑qt bags, each suitable for two 8‑inch containers, making it a good choice for specialty containers.