When I started gardening as a “hobby,” I was broke and in college. I quickly learned that pre-made seed starting mix was way too expensive for me (sigh), even though I was getting a discount because I worked at a hardware store.
With a small or large garden, it can feel like you’re losing money as you build the beds, fill the pots, buy the supplies, and feed the plants. That being said, I want to tell you that you can save money while still starting seeds. I find that making my own seed starting mix saves me the most money. The recipe only needs three easy ingredients that you can keep for a long time. Use what you want, when you want.
Ready to save money with my easy-to-make organic seed starting mix? Read on for the recipe that will always work.
Starting seeds is an exciting time for any gardener. Seeing those first tiny seedlings emerge brings hope for the bounty to come. But getting seeds off to a good start requires having the right soil mix. When it comes to starting vegetable seeds, not just any potting soil will do.
Why Seed Starting Mix Matters
Using a properly formulated seed starting mix is important for several reasons
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It is lightweight and fluffy, allowing delicate roots to easily grow and spread. Regular potting soil can be too dense.
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It retains moisture but also drains well, providing the right balance seedlings need.
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It is sterile, reducing the chance of diseases.
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It has a neutral pH that is ideal for seed germination.
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It has a fine texture so tiny seedlings are not overwhelmed.
Go Organic Whenever Possible
When buying a commercial seed starting mix, choose an organic option if you can. Organic mixes do not contain synthetic chemicals or fertilizers that could harm young seedlings. Look for mixes certified by OMRI (Organic Materials Review Institute).
You can also easily make your own organic seed starting mix at home.
How to Make Your Own Seed Starting Mix
Making your own organic mix is simple and ensures you get a high-quality soil. Here is an easy homemade recipe:
Ingredients:
- 1 part compost
- 1 part coconut coir or peat moss
- 1 part perlite or vermiculite
Steps:
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Mix equal parts compost and coconut coir or peat moss in a large container. Use a fork or your hands to blend thoroughly.
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Add equal parts of perlite or vermiculite and mix again. These provide air pockets in the soil.
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Moisten the mix with water until it is consistently damp but not soggy. It should clump together slightly when squeezed.
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Allow the mix to sit for 1-2 days so the ingredients fully blend.
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Use your homemade mix to start seeds!
This simple 50/50 blend of compost and peat/coir with perlite/vermiculite creates an ideal seed starting soil. Customize it based on what materials you have available.
Tips for Your Homemade Mix
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Use high-quality compost from your own compost bin or purchase organic compost. This brings nutrients and beneficial microbes.
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Coconut coir is more sustainable than peat moss. It also resists compaction better.
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Mix in a bit of worm castings for added nutrients if desired.
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Don’t use garden soil which can contain diseases, pests, and weed seeds.
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Avoid contaminated compost that could have chemicals or trash.
Testing Your Seed Starting Mix
How can you tell if your seed starting mix is well formulated? Here are a few simple ways to test it:
1. Look: Good mixes will be light, fluffy, and fine-textured. Wet a handful and squeeze – it should barely clump.
2. Feel: There should be a nice balance of moisture retention and quick drainage when wet.
3. pH: Test strips can confirm the pH is around 6.5, ideal for seeds.
4. Grow: Plant a few test seeds and ensure they germinate well and seedlings grow strongly.
Adjust your mix as needed based on these tests for optimal seed starting power. With the right soil, your vegetable seeds are sure to thrive!
When to Use Seed Starting vs. Potting Mix
It’s important to understand when to use a seed starting mix versus a potting mix:
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Seed starting mixes are used for starting seeds and cuttings. They are lightweight and sterile.
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Potting mixes are used for transplanting seedlings into larger containers. They contain more nutrients for established plants.
Seed Starting Mix: Seeds and cuttings
Potting Mix: Transplanting seedlings
Don’t use regular potting mix to start seeds or the denseness can inhibit germination. And don’t use seed starting mixes for long term potting or they lack nutrients.
Best Vegetables to Start from Seed
Many common vegetable varieties grow best when started from seed rather than buying transplants. Here are some top vegetables for starting from seed with the proper soil mix:
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Tomatoes – Start 8-10 weeks before transplanting. Choose small determinate varieties.
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Peppers – Need 10-12 weeks before transplanting. Start indoors in warm spot.
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Eggplant – Grow for 8-10 weeks indoors before moving outside.
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Broccoli/Cabbage – Grow for 5-7 weeks indoors before transplanting.
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Cucumbers/Squash – Start 3-4 weeks before outdoor planting. Use peat pots.
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Carrots – Can be directly sown outside but starting seeds inside gives a head start.
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Beans – Best direct sown but can get an early start indoors.
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Peas – Direct sow outside once soil thaws. But can start early indoors.
Play around with different vegetables to see which you prefer starting from seed yourself. Just be sure to use seed starting mix for best results.
Common Problems When Starting Seeds
Even with the proper soil, problems can pop up when starting vegetable seeds. Here are some common issues and solutions:
Leggy seedlings – Plants stretch for light from low light or high temps. Provide ample sunlight or cooler temps.
Damping off – Fungus kills seedlings at soil line. Use sterile mix and avoid overwatering.
Poor germination – Seeds fail to sprout due to improper planting depth or old seeds. Plant at correct depth and use fresh seeds.
Root crowding – Roots entangle when seedlings get pot bound. Transplant on schedule into bigger containers.
Insect infestations – Fungus gnats or other pests can plague seedlings. Use screens to keep out insects.
Pay close attention to your seeds and seedlings to catch any problems early. Take corrective action right away to get your vegetable plants off to a vigorous start.
Frequently Asked Questions
Here are answers to some common questions about seed starting mix:
What is the difference between seed starting and potting mix?
Seed starting mixes are lightweight, sterile blends designed specifically for starting seeds. Potting mixes are denser with more nutrients and made for transplanting established plants.
Is homemade or commercial mix better?
Homemade mixes allow you to control the ingredients but commercial mixes provide convenience. Both work well when formulated properly.
How long does seed starting mix last?
Plan to use seed starting mixes within 1-2 years before replacing. The nutrients and beneficial microbes decline over time.
Can you reuse seed starting mix?
It’s best to use fresh, sterile mix each season. Reusing mix increases the chance of diseases carrying over.
What can be used instead of peat or coir?
Good alternatives include shredded leaves, straw, grass clippings, paper strips, or bark fines. But peat and coir work well when sourced sustainably.
Can I start seeds in eggshells?
Yes! Fill eggshells with seed starting mix and place in an egg carton. The shells provide added nutrients as they break down over time.
When should I start seeds indoors?
Check the seed packet for recommended timing. In general start slow growers like peppers and tomatoes 6-8 weeks before your last expected frost. Quick growers like lettuce can be started just 2-3 weeks before transplanting outside. Stagger your plantings over several weeks for a continuous harvest.
Get the Best Start with Seed Starting Mix
Creating an ideal soil environment is crucial when starting vegetable seeds. Follow this guide and your seeds will thrive and grow into healthy, productive plants! Be sure to use a properly formulated seed starting mix, test for quality, and troubleshoot any issues that emerge. Your garden will flourish when you get your plants off on the right foot.
How to Make the Best Potting Mix for ‘Potting Up’ or Moving Seedlings to Bigger Pots
If you are going to “pot up” seedlings, which means replanting them in a bigger pot, but not yet moving them outside, I suggest starting with the enriched potting mix recipe. Once transferred to their new home you can add an amendment like liquid seaweed to your mixture. You can move germinated seeds to soil by following these steps. I will soon write an article about how I change my raised beds every season to get them ready for planting and how to properly “harden off” your seedlings.
Why do I move my small seedling to a bigger pot to give it more time to grow before transplanting? This is called “potting up.” But why would I do this? The weather might not be good for moving plants, or the plant may have grown too big for its pot.
ENRICHED POTTING-UP POTTING MIX
4 PT coco coir (or peat moss) 2 PT organic compost 1 PT perlite 1 PT vermiculite
What is Seed Starting Mix?
When you start your own seeds, you need to make or buy a mix that is lighter and finer so that the baby seedlings can easily grow roots without being squished. Seed-starting mix is a soil-less medium for starting organic seedlings. There is one major benefit to an organic diy seedling mix- COST!.
When I’ve bought bags of seedling mix in the past, the price was high for the amount I got. One bag never covers the amount of seedling trays I need to get started. Once I started making my own soil-less medium I quickly realized how much money I could save. Like, an 8-quart bag can cost up to $7–$8 and won’t even cover the cost of filling a 32-cell seed tray.
I get a little nervous when I start my seedlings because I grow plants for client gardens in Austin, Texas, for most of the year. I want full control over what ingredients are going into my seedling mix recipes. When purchasing pre-made bags of seed-starting mix you could be introducing odd chemicals to your germinating seeds.
Seedlings can grow on their own and don’t need extra food when they germinate, just like babies don’t need milk in their first few days of life; they only need colostrum. We want our seedlings to learn how to grow strong on their own, just like you want your baby to learn how to do tummy time, sit up, crawl, or walk. You will know what is going into your medium and save money by making your own seedling mixtures. A win-win!.