Learn how to make your own soilless potting mix at home! Commercial bagged soils are pricey, and if you use a lot, can add up to significant costs. They also vary greatly in quality and, in some cases, their fertilizer strength can be toxic to plants and cause burns to plant roots. It’s satisfying to make your own mix to give your plants a healthy start—and it leads to fewer headaches. Here’s our basic DIY potting mix recipe.
Containers are great for several reasons—they’re versatile and space-saving, and they allow you to be more efficient in your use of resources. If you have a small garden space or live in an apartment with a balcony or rooftop, containers are for you.
What Is Potting Mix?
For containers, you’ll often read that you need to buy or make a good potting mix. But what does this mean?
Potting mix is not garden soil—which is heavy and includes sand, clay, and other cheaper additives that won’t work for containers. Some people may refer to it as potting soil, yet potting mix is soilless. It’s lighter and fluffier than ground soil to allow enough air and water for healthy root growth and also provides enough anchorage for roots. These soilless mixes are sterile, so there is no chance of introducing pest or disease problems.
Potting mix can certainly be bought in bags at garden stores. Look for “Soilless Potting Mix,” which generally includes three ingredients: 1) peat moss or coconut coir for moisture and nutrient retention, 2) pine bark for anchorage, and 3) either perlite or vermiculite for air space, which makes the texture light and fluffy. Some potting mix also includes fertilizer or moisture-retaining treatments. If you use a potting mix with fertilizer, you’ll need to adjust the fertilizer you provide. (Think of salted butter versus unsalted butter in a recipe!)
But many gardeners who plant a LOT of containers or raised beds or start seeds indoors will mix up their own potting mixes! For the number of containers I use in my garden, I learned long ago that it’s much cheaper to make my own potting mix and store it in an extra trash can rather than pay for several big sacks of premade potting mix. Plus, I can customize the mix for a variety of different plants.
Before Making Your Own Potting Mix
Before we go any further, note that if you only need a few small containers’ worth of potting mix, you may actually be better off buying a premade mix! Making your own is usually only economical on a large scale. Here are a few things to keep in mind before creating your own mix:
- When it comes to any potting mix, the lighter it is, the better. Loose and porous mixtures not only make a container lighter to move, but they also transport water, fertilizer, and air to plant roots more quickly and allow for good drainage, which is important for container gardening.
- Start with the basic recipe below and then add soil sulfur to lower the pH or lime to raise the pH, according to the needs of your plants. Both additives can typically be found at garden centers. Plants such as lettuce, Russian sage, and marigolds prefer sweet soil with a pH of about 7.5, while others are acid lovers, like ferns, asters, and strawberries. They need a pH of about 5.5 to 6.0. Here’s a list of more plants’ pH preferences.
- If rapid drainage is needed, as is the case for cacti, succulents, and lavender, add extra sand and perlite.
- If greater moisture retention is needed, as is the case for ferns and woodland flowers (like primrose) add extra vermiculite or coconut coir.
My Basic Container Potting Mix Recipe
Ingredients
- 1 bucket (10 quarts) coconut coir
- 1/2 bucket (5 quarts) perlite
- 1/2 bucket (5 quarts) vermiculite
- 1/2 bucket (5 quarts) screened compost or composted cow manure
- 2 cups fine sand
- 2 cups pelleted time-release fertilizer
Instructions
Mix thoroughly. It makes enough to fill two 14-inch tubs or five 12-inch hanging baskets—double or triple the recipe for bigger containers.
Credit: Cem Selvi
How Much Potting Mix Do I Need?
Take out the guesswork and use our soil calculator for containers.
Potting mix is sold by volume (typically measured in quarts), and most pots are measured by their diameter. To translate quarts of mix into various pot sizes, use this quick reference:
Pots & Tubs | |
|---|---|
| Container Size | Amount Needed |
| 8-inch | 3 quarts |
| 10-inch | 6 quarts |
| 12-inch | 8 quarts |
| 14-inch | 12 quarts |
| 16-inch | 20 quarts |
| 20-inch | 24 quarts |
| 24-inch | 28 quarts |
| 30-inch | 72 quarts |
| 36-inch | 96 quarts |
Hanging Baskets | |
| 12-inch | 6 quarts |
| 16-inch | 10 quarts |
Window Boxes | |
| 24 inches by 6 inches | 12 quarts |
| 36 inches by 6 inches | 20 quarts |
Learn More
Here’s another potting mix recipe for seed-starting—with a video demonstration!
See our Plant Growing Guides for advice on planting and growing popular vegetables, fruits, and flowers!
Do you make your own potting mix? Share your recipe in the comments below!
More Like This
The recipe above is suitable for almost anything; as noted, the soil pH may need to be adjusted. The pH for lawn grass should be 7. If the pH of the soil mix is too low, add lime. If it's too high, add ground sulfur. You can test the soil's pH with an inexpensive kit available at most home and garden supply stores and nurseries.
Read the ingredients on the bags. You want enough "dirt" in the garden plants to hold some moisture and fertilizers/nutrients you might add. Desert plants, the rose included, tend to be particular about water/drainage. The desert rose is a succulent. It needs conditions that are bright, warm, and dry. Therefore, you do not want to over water nor have water collect in the container, so the cactus/palm soil is best for the desert rose, as cactus and palm are also desert plants. Soil for the bonsai would depend on the plant.
Make sure that the cow manure is aged (usually a year is safe). Perlite, check. Coco Coir, ok (it adds to the absorbency and drainage of potting soil and is used as an amendment). Soil made of old tree leaves...if it's a very old decomposed pile it might just be fabulous. To be sure on all of this you might do a soil test (get a kit at a garden store) and check the mixture's pH vs that which your crop needs. (You did not say what you are growing.)
Adding some compost is a good idea. Your tomatoes should be fine.
- « Previous
- 1
- 2
- …
- 10
- Next »
Comments