Comparison: Best Soil For Plants Price (Updated | Nov 11th)

Indoor mixes are formulated to retain moisture and reduce fungus gnats, often using peat, coir, and perlite, while outdoor mixes focus on drainage and include ingredients like sand and compost for tougher weather conditions. Look at the plant type and where it will be placed; houseplants benefit from a lighter, sterile blend, whereas garden containers need a mix that can handle rain and wind. Checking the product description for indoor‑specific claims, such as gnat resistance, can help you choose the right formula.

Organic mixes contain naturally sourced peat, coir, and a quick‑release natural fertilizer, offering a more environmentally friendly option and often better long‑term soil health. They still provide up to two months of feeding, but the nutrients are derived from organic materials rather than synthetic chemicals. If you prioritize sustainability and want to avoid synthetic additives, the organic lines are a solid choice.

The Miracle‑Gro Houseplant Potting Mix and the Indoor Potting Mix both highlight reduced gnat susceptibility, thanks to their blend of perlite, sphagnum peat, and coconut coir that lack compost or bark—common gnats habitats. These mixes also include a balanced fertilizer that feeds plants for up to six months, keeping roots healthy and less attractive to pests. Choose either of these if gnats have been a recurring problem.

Moisture Control uses an AquaCoir formula that absorbs up to 33 % more water and includes a wetting agent, helping prevent both over‑ and under‑watering. It does not contain sphagnum peat moss, which can make the mix lighter and quicker to dry out compared to the standard blend. This makes it ideal for plants that need consistent moisture levels, such as vegetables and herbs.

A 16‑quart bag of most Miracle‑Gro mixes (Indoor, Outdoor, or standard Potting Mix) is designed to fill one 12‑inch pot, while a 4‑quart bag of the Houseplant mix fills an 8‑inch pot, which you would need two for a 12‑inch container. If you have multiple pots, consider the value packs that include two 16‑quart bags for the standard mix or two 8‑quart bags for the Moisture Control mix, offering better price per volume. Always check the product details for exact coverage recommendations.

The organic mixes provide a quick‑release natural fertilizer that feeds plants for up to two months, which is sufficient for most seasonal growth cycles. While synthetic blends often claim up to six months of feeding, the organic version delivers nutrients in a more gradual, environmentally friendly manner. For most home gardeners, the difference in performance is minimal, but the organic option reduces synthetic chemical use.

The Miracle‑Gro Cactus, Palm & Citrus Potting Mix is specifically formulated for fast‑draining conditions, which are essential for succulents and citrus roots to avoid rot. It also includes Miracle‑Gro Plant Food to promote healthy growth in these demanding plant types. If you need a versatile option for both indoor and outdoor succulents, this blend is the most suitable.

Value packs that include two 16‑quart bags (standard Potting Mix) or two 8‑quart bags (Moisture Control) generally lower the cost per quart by 10‑15 % compared with single‑bag purchases. The larger 25‑quart Outdoor Organic pack also offers a reduced price per quart, especially when filling multiple large containers. Calculating the total price divided by the total quarts will reveal the best savings for your garden size.