Resources / Soil basics
By Sawgrass Organics · Updated September 18, 2026 · 3 min read
Use a potting mix suited to your plant for containers. Use compost to amend existing soil. For an in-ground bed, start with the soil you have and choose amendments from a soil test.
What is the difference?
A bag of compost and a bag of potting mix may both look dark and crumbly, but they are designed for different jobs. Start with where the roots will grow, then read the intended-use directions on the bag.
| Material | What it does | Where to start |
|---|---|---|
| Potting mix | A blended growing medium intended to support roots in a container. | Repotting houseplants, patio pots, and container herbs; match the blend to the plant. |
| Compost | Decomposed organic material used as an amendment or an ingredient in a growing mix. | Improving existing soil or a specific blend that calls for compost. |
| Garden soil | The mineral soil in your garden; bagged products with this name have their own directions. | In-ground planting and appropriate bed mixes. |
Container roots need a balance of water and air in a limited space. Ordinary garden soil can become too dense in pots, which is why a formulated growing medium is usually the easier starting point. See the University of Maryland guide to container growing media.
Choose by the project in front of you
- A new basil plant in a patio pot: begin with a container mix, a pot with drainage, and a spot that meets the plant's light needs.
- An established vegetable bed: assess the soil before adding another layer of amendment. The bed may need a different change than the pot beside it.
- A new framed raised bed: select a suitable soil blend for the entire bed. Compost can be one ingredient; do not assume it should make up the whole fill.
Oregon State Extension recommends a soil mix for framed raised beds and cautions against filling them entirely with compost. Its compost guide explains the difference between filling a bed and amending one.
Three questions to ask before opening a bag
- What job is this product intended to do? Look for container use, soil amendment, or a specific plant application.
- What is already in the blend? A compost-based potting mix already includes compost. Adding more is a formulation change, so follow the manufacturer's guidance.
- Does my plant need a specialist mix? An all-purpose label is a starting point. Check the needs of orchids, cacti, and other plants with particular root conditions.
Common questions
Can I plant directly in compost?
Some plants and growing systems can use particular composts successfully. That does not make every compost a ready-to-use container mix. Check the product directions instead of treating all composts as interchangeable.
Does compost replace fertilizer?
It can contribute nutrients, but the supply varies and may not meet the needs of a whole growing season. Match feeding to your plant and the directions for your mix.
Which Sawgrass product fits?
Sawgrass Organics Potting Mix is our peat-free blend of aged compost, coco coir, and fine biochar. Coastal Compost is our marine-based compost amendment. Choose the product by the job, then follow its use directions.