Best Seed Starting Mixes of 2023
When it comes to getting seeds started, don’t skimp on the basics. Be sure and lay a good foundation for your plants by choosing one of the best seed starting mixes.
When it comes to seed starting mixes, you can’t go wrong with Espoma. Light, airy soil that’s pH balanced. Inoculated with mycorrhizae to encourage root development. This is one of the few mixes that bares the USDA approved organic label on the bag.
| Specifications | |
|---|---|
| Ingredients | sphagnum peat moss, perlite, yucca extract, lime (to correct pH), worm castings, endo & ecto mycorrhizae |
| Quantity | 16 quarts |
| Organic | Yes |
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Choosing the right soil can be a bit confusing with all the various terms used for seed starting mix. Some companies call it seed starting mix, some call it seed starting potting soil, and others seed starting soil. The names are all synonymous. Just keep in mind that it should specify that it’s intended for starting seeds. Don’t use regular potting soil in your seed starting trays.
What kind of soil is best for starting seeds?
Consider the Components
Seed starting mix is usually soilless. That’s right, there’s no need for soil in it. The three main components of a good mix are perlite, vermiculite, with coconut coir or peat moss as a base. Different ratios of these ingredients can be used depending on which base is used. However, it is entirely possible to use pure coconut coir to start seeds. You may also find that some mixes may also contain additives in the form of humus, mycorrhiza and dolomite lime (to balance pH) if the soil mix contains peat moss.
The reason for using such inert ingredients for a growing medium is that the seeds contain enough nutrients for the first weeks of life of the seedling. Think of it like an egg and a yolk. After a few weeks, when the seedlings have grown larger, they can be fertilized or transplanted into more nutrient-rich soil.
Qualities of the Best Seed Starting Mixes
The most important quality of the best seed starting mixes is the ability to retain moisture while providing adequate drainage. Seeds need enough moisture to germinate. However, if the soil doesn’t drain well, the seeds can rot or mold before they germinate.
Soggy soil will also be a problem once the seedlings sprout. Soil that retains too much moisture will also lead to issues like dampening off where the seedling simply rots off at soil level.
Best Coconut Coir Mix – Burpee Coconut Coir Seed Starting Mix
Organic Seed Starting Mix – Pro-Mix Organic Seed Starting Mix
Best Budget Friendly Mix – Miracle-Gro Seed Starting Potting Soil
Best Seed Starting Kit – Jiffy Seed Starting Greenhouse with Peat Pellets
Do Your Research
It’s tempting to just grab the first bag of seed starting mix you see on the shelf but it’s always good to do a little research. Some mixes may include synthetic fertilizers or other ingredients you may not desire.
Another great way to evaluate a product is to read reviews of seed starting mixes on Amazon. Just keep in mind, people don’t always take the time to list the positive qualities of a product but they are quick to post negative feedback. Look for trends in bad reviews. If many people are saying the same thing about a seed starting mix, it’s probably true but you can usually disregard the lone negative quality.
How We Pick the Best Seed Starting Mixes
Our top picks include lightweight soils that drain well but retain adequate moisture and are free of contaminants. We only recommend products made from quality ingredients. You’ll also see options for those who only prefer organic farming. While it’s ideal to buy the best possible medium, we also list at least one quality, but budget friendly, seed starter mix.
Burpee Coconut Coir Seed Starting Mix
Burpee is a leading name as a seed vendor and now they offer a seed starting mix. We love these compressed blocks. You’ll be amazed at how much these blocks expand when you add water. No additives needed, just fill your trays with this pure coconut coir.
| Specifications | |
|---|---|
| Ingredients | 100% coconut coir |
| Quantity | Makes 16 quarts once rehydrated |
| Organic | Yes |
Jiffy Natural & Organic Seed Starting Soil
Pro-Mix has many soil offerings, including this organic seed starting mix. The peat in this product comes from bogs that are certified under the Veriflora Program, an agricultural sustainability certification.
| Specifications | |
|---|---|
| Ingredients | Sphagnum peat moss, coco fibre, perlite, lime, organic fertilizer, mycorrhizae |
| Quantity | 16 quarts |
| Organic | Yes |
Miracle-Gro Seed Starting Potting Mix
Miracle-Gro has built quite a name in the gardening scene over the years. They offer two 8-quart bags of this seed starting mix for a great price. The mix contains a bit of helper nutrients to aid with root development.
| Specifications | |
|---|---|
| Ingredients | Peat moss, Perlite, Miracle Gro fertilizer and a wetting agent. |
| Quantity | Two 8-quart bags (16 quarts total) |
| Organic | No |
Jiffy Seed Starting Greenhouse with Peat Pellets
We decided to include this nice greenhouse kit from Jiffy for those that may not like messing with bags of soil. This kit includes compressed peat pellets that can be rehydrated, two watering trays, and two humidity domes.
| Specifications | |
|---|---|
| Ingredients | Peat moss |
| Quantity | 72 peat pellets |
| Organic | No |
Frequently Asked Questions
How do I choose a good seed starting soil mix?
Moisture Retention and Drainage
When looking for a quality seed mix, make sure it’s lightweight and drains well but holds moisture. You must ensure that the seed trays stay moist during the germination period. Also, light, airy, well-drained soil allows oxygen to reach the roots if seedlings are watered after sprouting. Coco coir has the ability to hold eight times its weight in water without getting soggy. It’s easy to see why many blends have replaced peat moss with coconut coir in recent years.
Sphagnum Moss or Coconut Coir
Peat moss has been the main ingredient in some of the best seed starting mixes for many years. In recent years, however, many of the mixes have replaced peat moss with coconut coir. Mainly because coco coir is considered a renewable raw material. In addition, peat moss needs additives like lime to balance the pH. Peat moss can also become water resistant and difficult to rewet when completely dry. For these reasons, we prefer starter mixes made from coconut fiber.
Perlite and Vermiculite
The addition of Perlite improves drainage. Vermiculite is added to mixtures to retain moisture.
Sterilized or not
Sterilization is done by heating the mixture. This process will kill the bad stuff, like fungus gnat larvae, in the soil. This is one of the main advantages of using sealed bags of starter mix over the bags of potting soil typically found stored outdoors at garden centers. Using a sterilized mix ensures that the seedlings will not be attacked by fungi or other pests in the soil.
Is sphagnum peat moss good for starting seeds?
Absolutely, it’s been the main ingredient in seed starter mixes for years. The only issue with using peat would be pH. Ready-to-use peat moss mixes usually contain dolomite lime to balance the pH. If you make your own seed starting mix or potting soil, be sure to add lime. You’ll also need to add some perlite to help improve drainage.
How much seed starting soil mix do I need?
An 8 qt bag of seed starting mix will fill, at least, two 10×20 seed starting trays (72 small cells).
Can I use regular garden soil to start seeds?
You could, but it’s not recommended for a number of reasons. Garden soil, from the ground, can be too dense for seed starting. It may stay too soggy and lead to moisture related problems such as dampening off. Another reason not to use garden soil for planting is the pests it contains, with aphids being the biggest concern. The garden soil will almost certainly harbor pesky parasites.
Can I reuse seed starting soil mix?
It is entirely possible to reuse the seed starting mix. You don’t have to worry about it being depleted of nutrients since it was inert from the start. Just remember that it is no longer sterile. However, you can sterilize the mixture by heating it in the oven or microwave.
I hope this review has been helpful in finding the best seed starting mixes for your application. If you are looking for seeds to fill your trays, please feel free to visit our seed store.