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Garden Betty

you don't need all those things in your seed starter mix


Last week, Punxsutawney Phil (the celebrity groundhog) said there would be 6 more weeks of winter...

Which means it might be time for you to start your seeds indoors (or at least start thinking about it) so your seedlings are ready to transplant once the weather warms up.

Because I like to save money (and I bet you do, too), I often make my own seed starting mix at home. And why would I do that, considering you can find seed starting mix in stores right now?

This is why:

Some—not all—seed starting mixes have unnecessary additives that help with wetting the mix. But if you saturate the mix thoroughly before planting and keep up good watering practices, your seed starter doesn't need any wetting agents.

(Wetting agents can actually lead to fungal diseases if you don't watch your moisture and humidity levels.)

Then there's also this:

Seed starting mix doesn't need all those soil boosters and fertilizers. Seeds come with everything they need to germinate and survive the first couple weeks.

​(Here's a cool visual guide I created on what happens when a seed germinates.)​

The cotyledons (those first green "leaves" that appear) store the seedling's initial supply of nutrients. Only when the cotyledons fall off and the first true leaves appear do seedlings require outside nutrients to thrive.

So if you usually transplant seedlings a couple weeks after germination, there's no need to spend extra money on premium seed mixes when you'll be repotting them in potting soil (or outside in the garden) anyway.

​Here's how you can DIY your own seed starting mix (and save money) using 3 simple ingredients. (Updated this year!)​

If you start lots of seeds every year, it's also worth buying the ingredients in bulk, mixing them up, and storing this blend in a large bin (or a lidded trash can) so it's always ready to go!

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Some common questions I get about seed starting mixes:

Do you really need to start your seeds in seed starting mix?

No, not at all. Seeds sprout just fine in the ground. But if you're starting seeds indoors, regular garden soil is often too dense and full of weeds or unwanted hitchhikers, making it more challenging to manage inside with limited soil volume.

Is this seed starting mix sterile?

No, and it doesn't need to be. Sterilization rids the soil medium of all bacteria, including the good bacteria that plants need to survive. Please don't follow the suggestion of other blogs out there and bake your seed starting mix in the oven. It's so unnecessary!

Doesn't peat moss make the seed starting mix too acidic?

I just updated my post with NEW information about this, based on my own observations and experiences. You might be surprised by what I found out!

​

P.S. If you don't want to make your own seed starting mix, here's a store-bought mix I've had good results with in the past.

P.P.S. Ready to get more organized in the garden this year? Let my Ultimate Garden Diary help you keep track of all the things!

Inventory your seeds and soil amendments, record important dates (like seed germination, transplanting, and first blooms), and write down everything you want to remember about your garden in one place.

Garden Betty

For people who want to grow more food with less work. 🌱 This is my weekly newsletter loved by 38,000+ subscribers—here's what one of them had to say: "These are not the regular run-of-the-mill garden-based emails. You actually touch on more unusual tidbits that encourage me to keep growing and learning."

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