Quick Answer (the whole recipe)

If you want a potting mix that grows massive harvests, drains well, holds moisture, and stays light so roots can fly—this is the base mix I’ve used for years:

3 parts coco coir (or peat moss), 2 parts compost, 1 part (½ part vermiculite & ½ part perlite).

I call it the 3-2-1 because the two halves add up to one whole. This mix is built for soil structure first. Then you add nutrition based on what you’re planting.

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First: this is potting mix, not “soil”

I call it soil sometimes, but technically it's potting mix.

To be “soil,” it would include topsoil—and I actually like that this mix doesn’t. Topsoil can introduce weed seeds and make mixes heavier. This recipe stays clean, light, and easy for roots to move through.

Bottom line: better structure = healthier roots = stronger plants = better harvest.

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Why this mix works

Many garden problems come down to one thing: roots struggling. Roots need moisture (but not swampy), oxygen (they can’t live in suffocating mud), and space to move (compacted media slows everything down).

This 3-2-1 recipe gives you a mix that holds water but still drains, stays fluffy, and makes it easy for roots to expand fast. That’s why plants explode with growth when you get it right.

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Ingredient 1: The Base (Coco Coir vs Peat Moss)

Option A: Coco coir (my favorite)

If you want the easiest, most forgiving base, I prefer coco coir because it’s less acidic overall (it’s roughly pH 5.5 to 6.8). It stays looser and doesn’t compact into a brick as easily, and it rehydrates well—even if it dries out. Coco coir also has those little stringy fibers that help with soil structure.

Important note: Use high-quality, low-salt coir.

Option B: Peat moss

Peat moss works too, but it’s more acidic (pH ~3 to 4.5), more likely to compact, and can become hydrophobic (hard to rewet) if it dries completely.

If you’re using peat moss and growing crops that prefer a more neutral/less acidic soil (like cucumbers or cabbage), you may want to balance that pH with lime (go slow and follow product directions).

Can you mix coir and peat?

Yes. I’ll sometimes mix in peat with coir. You can keep it simple with coir as the base, or swap in some peat depending on what you’re growing.

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Ingredient 2: Compost (the “life” in the mix)

Compost brings a lot to the table. It improves structure, retains moisture, provides macronutrients (NPK), and adds trace minerals and beneficial microbes (bacteria, fungi, etc.).

My go-to: mushroom compost

I use mushroom compost a lot because I can get it locally in bulk. The key is quality and consistency. Two important notes about mushroom compost. Firstly, it may not be finished when you get it. Second, it can sometimes have extra salts

Best-case scenario: let it sit and mellow out (even up to a year). If you can’t, you can still use it—pay attention to how your plants respond.

Can you use bagged compost?

You can, but the quality of bagged compost varies. Some bags are loaded with woody fillers. You want compost that looks and feels like compost—not like a pile of sticks.

Can you use worm castings?

Worm castings are fantastic… but you’d need a lot of them to replace compost entirely. I like castings as an upgrade, not as the bulk compost base.

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Ingredients 3 & 4: Vermiculite + Perlite (don’t skip these)

These two ingredients are different—and I highly recommend using both.

Vermiculite = moisture retention + lighter mix

Vermiculite is light and holds water well. It keeps the mix from getting too dense. Skip vermiculite, mixes can dry too fast and lose that moisture buffer.

Perlite = aeration + drainage

Perlite doesn’t hold much water. It creates air pockets and improves drainage—roots love that oxygen. Skip perlite, mixes can get heavy and wet.

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How to Prep Coco Coir (so your ratios don’t get messed up)

If you’re using coir bricks:

Soak the bricks in a tote/bin of water until fully expanded. Break it apart so it’s evenly hydrated. Drain it in a bucket with holes so it’s moist—not soaking wet. Then measure your parts

If the coir is dripping wet, your “3 parts” becomes “3 parts + a bunch of extra water,” and your mix gets sloppy.

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My Favorite Way to Mix It (tarp method)

This is the easiest way to get everything evenly blended.

Step-by-step mixing

Spread out your coco coir on a tarp (3 parts). Add vermiculite and perlite on top (so they don’t blow away). Dump compost on top. Flip the tarp corners inward to tumble the pile. Rake it out flat. Flip again from all corners. Finish mixing with your hands (best way to feel the texture)

You’ll know it’s right when it is dark and fluffy, not clumpy, not dusty, and holds moisture but doesn’t smear like mud.

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Where to Use This Mix

This base mix is excellent for raised beds, containers, direct sowing (seeds push through easily), and transplanting (roots love it). This is a foundation mix. The only missing piece is…

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Nutrition: Why this is a “base mix” (and how to feed it)

This mix is built mainly for structure.

Depending on the compost you use (especially compost that’s already been “used,” like mushroom compost), it may not have the nutrition to carry heavy-feeding plants all season.

The simple approach I use

I fill or top off the bed with the base mix, add an all-purpose organic fertilizer, mix it into the top layer, and water it in! I like keeping fertilizer in the top zone because watering moves nutrients down into the root area over time. Follow label directions on any fertilizer you use.

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Crop tweaks (simple adjustments based on what you’re growing)

If you’re growing tomatoes (and other acid lovers)

Tomatoes generally do well with slightly more acidity. A straightforward option is to replace one of your coir “parts” with peat moss to nudge the mix toward greater acidity.

If you’re growing leafy greens (like lettuce)

Leafy crops love nitrogen. You can carefully add a nitrogen-forward amendment (like blood meal). Again, follow the label instructions, and don’t go crazy.

Transplant boost: mycorrhizal inoculant

When transplanting, adding mycorrhizal inoculant to the roots can help reduce transplant shock and support growth. It’s a simple add-on that can make a difference.

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Want an “advanced” mix? Start here, then customize

If you want to level it up, this base is where you start.

Optional add-ins people use for an extra boost are worm castings, kelp meal, neem seed meal, fulvic acid, seaweed extract, lime (for balancing acidity when needed), and biochar (some people love it; I’m not obsessed, but it can work).

Please keep it simple first. Most beginners win by getting structure + basic fertility right before stacking the 10th Amendment.

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The Team Grow way (why this matters)

If you’ve struggled in the past, I’m telling you—soil is one of the foundations. Good soil + healthy plants get you most of the way to a plentiful harvest… as long as you also protect your plants from pests. And if you want to go deeper with support, feedback, and growers helping growers, our community is for you.

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FAQ (Quick Answers)

What’s the best potting mix recipe for raised beds?

Use the 3-2-1 base: 3 parts coir/peat, 2 parts compost, ½ vermiculite, ½ perlite. It’s designed for structure: moisture + drainage + air pockets, so roots grow fast.

Coco coir vs peat moss: which is better?

Coco coir is typically less acidic, stays more open, and rehydrates more easily. Peat can be more acidic, can compact, and can resist water if fully dried.

Why does peat moss get hard to re-wet?

When peat dries out completely it can become hydrophobic, so water runs off or channels through instead of soaking evenly. Prevent full dry-outs or rehydrate by soaking.

Do I need lime if I use peat moss?

Sometimes. Peat can be more acidic, so if you’re growing plants that prefer a more neutral soil, lime can help balance—but go slow and follow label instructions.

What compost is best for this mix?

High-quality compost that’s consistent and not full of woody filler. Mushroom compost can be great, but watch for unfinished composting and potential salts depending on the source.

Do I need both perlite and vermiculite?

I recommend it. Vermiculite holds moisture and lightens the mix; perlite adds aeration and drainage. Together, they balance water + oxygen.

How do I hydrate Coco Coir bricks?

Soak in water until expanded, then break apart and drain until it’s moist (not dripping) before measuring your “parts.”

What’s the easiest way to mix potting mix?

A tarp. Layer ingredients, flip corners to tumble, rake it out, flip again, then finish by hand.

Is this “soil” or “potting mix”?

Technically, a potting mix. It doesn’t include topsoil, which is often a good thing because topsoil can carry weed seeds and add heaviness.

Is compost enough to feed plants all season?

Sometimes, but often not for heavy feeders. This is a base mix—add an all-purpose fertilizer, then customize it based on the crop.