DIY Potting Soil Recipe to Save Money
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.
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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?
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!
Robin Sweetser
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Great article, except for the sand used.
Typically, you'd want to go for a course sand. Fine sand fills the tiny gaps, working against the drainage ingredients.
I normally make my potting soil as below and it has given good results throughout.
1/3 coir 1/3 yard compost and 1/3 garden soils or soil and sand mixed equally. I also heat soil to 60 deg C for about 20 minutes to kill unwanted Organics including seeds to sterilise. It is also advised to sterilise the vermicompost as above, if it is from unknown source. Also it is better to wash the coir 2 or 3 times to remove its acidic nature and dry it well. I also add a dash of oil cakes of neem, peanut and sesame seeds. Adding phospho-bacterium and Trichoderma viride helps in providing microbes and fungal resistance to saplings/seeds. Hope this helps.
My recipe for soil includes screened mulch, egg shells, coffee grounds, fireplace ashes and finely shredded paper mixed in a 50 gal drum
Please inform your readers of the negative environmental effects of peat moss and promote sustainable alternatives instead, like coconut coir.
Peat moss takes tens of thousands of years to form in bogs, then is dug up and put in bags for gardeners in a matter of days. That natural wetland bog environment uses the peat to filter and purify water, and thousands of animal species live in bogs. Draining and digging them up for gardeners is unsustainable and bad for the environment. The bogs will never recover fast enough for more peat to be harvested in the same area, so new bogs must be destroyed all the time. Digging up peat bogs releases massive amounts of CO2 into the atmosphere and peat moss is often exported from poor countries to be shipped to rich countries at non fair-trade prices.
Peat bogs are even known to catch on fire when they are drained, and the peat can burn underground for months on end, releasing tons of smoke, CO2 and other hazardous chemicals into the air.
Consider buying compressed coconut coir online for adding organic matter to soil. Unlike peat moss, coconut coir is completely renewable (it's made from waste coconut shells), and is pH neutral (peat moss is acidic). It ships in small cardboard boxes, which is better for the environment than giant plastic bags filled with peat.
You have a responsibility to the Earth and your readers to be informed about these types of concerns.
Good to know about the peat moss!
Please note and proceed with caution: "Toxicity to Cats: Coconut coir itself is not typically toxic to cats, but it can cause gastrointestinal distress if ingested. Cats may be attracted to the texture and taste of coir, which can lead to ingestion and subsequent health issues. In severe cases, it may even lead to intestinal blockages, requiring immediate veterinary attention."
Sorry
Disagree with the anti peat moss poster
Peat is sustainable as MORE is replaced by nature each year than us harvested by man.
Yes coco is a by product of the coconut industry; the same industry that destroys more forests every year to plant more coconut trees.
Get the facts
Don't be lazy, read ALL available information; NOT JUST THE INFORMATION THAT YOU AGREE WITH
Everyone with the space to do it SHOULD BE COMPOSTING
forget about fancy silly tumblers
Just get some large used nursery pots
10-15 gallon
Grind up your material
Fill the pots 3/4 full
Stack the pots one atop the other 3-5 pots high in a shaded location
Toss some worms in the top most pot
Add water to the top pot until you see it running out of the bottom pot
Every 2-3 weeks check the moisture in the pots
Don't let them dry out
Every 1-2 months; dump the contents of each pot into another pot; this is the easiest way EVER to turn your compost
Children and old people should be able to lift a 10 gallon container 3/4 full of compost!
You should notice that the compost is breaking down
Depending on the size of the pieces that started with it should take 4-6 months to be ready to use
Handy to make a screen frame out of 1/2 square hardware cloth and some scrap wood that fits over the top of a wheel barrow to screen the finished compost
Just put the pieces that won't pass through the screen back in the pots and give this material for time to break down
I have tried every possible method of making backyard compost over 50 years
This is the absolute easiest way to make nice diy compost with minimal work
Good luck
You can educate people without insulting them.
Thanks that was a very helpful as well
No one sells real peat bog moss anymore, relax. Nearly everything sold in the us market as peat is simply composted lumber mill waste from canada. Yes it's a scam. But it's much less of a scam than pretending that mass monoculture coconut farms destroying jungle and shipping the discards 5,000 miles on diesel ships is carbon neutral.
