The best gardeners always use a quality seed starting mix, so plants are ready for transplant outdoors.
Using the best seed starting mix gives you a jump on the gardening season so you can harvest vegetable crops sooner and have lush flowerbeds your neighbors will envy!
Seed Starting Mix Requirements I Look For:
|For Organic Gardening
|For Good Aeration And Moisture Retention
|Doesn’t Require A Lot Of Other Materials
|Includes Nutrition Required For Seedlings
My Picks For The Best Seed Starting Mix
Best Overall Seed Starting Mix
Miracle-Gro Seed Starting Potting Mix
Reasons To Buy
- Lightweight mixture allows for good root development
- Complete with Miracle-Gro plant food, so seedlings get full nutrition
- Works well for establishing cuttings
- Best for starting vegetable plants
Reasons To Avoid
- The organic matter in the mix can be very chunky, which you may need to sift out
- The looseness of the soil mix makes it hard to transplant seedlings without uncovering the root
The Miracle-Gro Seed Starting Potting Mix blends a lightweight growing medium with their famously effective fertilizer that targets proper root development, so your plants grow vigorously.
I like the one-and-done approach to seed starting this mix provides, which reduces the time spent prepping and tending your trays. I also like how well this 8-quart mix works for propagating cuttings from roots or stems.
On the downside, you need to remember first to fill the seed-starting tray, then slowly water and drain the soil before adding seeds, or you can end up with a mess. I also suggest using biodegradable trays with this mix, as it’s very loose and makes transplanting difficult otherwise.
Miracle-Gro Seed Starting Potting Mix is a top choice because it provides a clean, nutrient-rich blend that is best for vegetable gardeners wanting strong root and plant growth.
Best Seed Starter With Peat Moss
Black Gold Seedling Mix
Reasons To Buy
- Suitable for organic gardening
- Ideal aeration and moisture levels for fast seed germination
- Peat moss and other minerals provide gentle nutrition for root development
Reasons To Avoid
- Very loose texture requires the use of biodegradable trays for transplanting
- Not enough nutrition in the mix for long-lasting growth
The Black Gold 8-Quart Seedling Mix features a higher concentration of peat moss in their formulation, which increases both aeration and moisture retention, so seedlings thrive.
I like that this mix has an Organic Materials Review Institute listing for safe, organic gardening practices and that seeds germinate quickly and grow strong.
On the downside, there is less nutrition in this mix than others, so do expect to add fertilizer after sprouting if you don’t plan to transplant them into regular potting soil, or you may see wilting.
The Black Gold 8-Quart Seedling Mix gets top marks for the quickness of germination and root development. This seed starting mix is best for those who want a seed-to-table organic garden experience.
Best Coconut Coir For Seed Starting
Burpee Organic Coir Compressed Seed Starting Mix
Reasons To Buy
- OMRI listed for organic gardening use
- Easy to store and stack blocks take up less space
- Mixture remains airy so roots can develop quickly
- Sterile, so hidden pathogens won’t harm seedlings
Reasons To Avoid
- Requires more time and mess before adding to seed trays
- Zero nutrition means you must add fertilizer immediately after sprouting
The Burpee Organic Coir Compressed Seed Starting Mix comes in easy-to-store blocks that break apart into a rich soil blend when you add water.
I like the lightweight, and airy texture coconut coir provides as a perfect base for starting any seed type. I also am fond of the organic, environmentally-friendly, 100-percent biodegradable resource this product creates by recycling harvested coconut husks.
On the downside, you will need more prep time to use this seed starter as it has to sit in a container with water for several minutes to expand. Once it absorbs the water, you need to use your hands to break apart the lumps into a nice soil consistency.
Burpee Organic Coir Compressed Seed Starting Mix is a top-five selection for the sterile, lightweight, and eco-friendly blend that is ideal for organic gardeners who want quick germination.
Best Balanced Seed Starter Soil
Hoffman Seed Starter Soil
Reasons To Buy
- Balanced blend of ingredients encourage healthy root growth
- High germination rate for both vegetables and flowers
- Sterile medium that prevents pest or disease issues
- Excellent drainage to prevent root rot
Reasons To Avoid
- Zero nutrients means you must watch seedlings closely so you can add fertilizer at the correct growing stage
- Need to mix with water for an hour before adding to planting trays
The Hoffman Seed Starter Soil is 18 Quarts and features a blend of six ingredients that perfectly balance to provide seeds a healthy start in life.
I like the large quantity for the price so that you can fill more trays affordably. The texture and moisture control of the mix is also beneficial for the root development of seeds or cuttings without any fear of rotting.
On the downside, this is another nutrient-free seed starting mix, which means you’ll have to add fertilizer of your choice once the first real leaves appear.
The Hoffman Seed Starter Soil rounds off the top five for its affordable large quantity and texture that promotes good drainage as well as establishing a strong root system. This seed starter mix is best for greenhouse gardeners who like to grow a variety of plants.
Best Organic Seed Starter
Jiffy Natural & Organic Starter MixNo products found.
Reasons To Buy
- OMRI certification for organic gardening
- Nice blend of natural ingredients for fast and strong seed growth
- Lightweight, yet retains moisture and won’t compact
- Plant cuttings, tomatoes, and peppers excel in this mix
Reasons To Avoid
- Need to pre-mix the soil with water before adding to trays or pots
- Will need to add fertilizer to seedlings after a week or so or growth
The Jiffy Natural & Organic Starter Mix is 12 Quarts and has the perfect consistency to fill seed trays, especially when greenhouse gardening.
I like the entirely organic ingredients that hold moisture well, allows good aeration so roots can expand, and provides a stable base to secure plants as they grow. I also appreciate the resealable bag, which makes storage simple.
On the downside, you must blend this seed starter mix with water (as directed) before adding it to your trays, which is an extra step you may find annoying.
What puts the Jiffy Natural & Organic Starter Mix high on the list is the OMRI certification and overall texture that increases root development. This mix is best for organic gardeners who don’t mind taking the time to pre-prep with water before adding to trays.
Seed Starting Mix vs Potting Soil
Here is a fast breakdown of the differences between a seed starting mix versus potting soil, so you understand why one is better than the other in gardening applications.
Seed Starting Mix
Seed starting mix gives seeds the boost they need to start life but isn’t for use during the plant’s entire life cycle. The mixture is light and fine so that the seed can germinate without stress, and the roots can spread quickly.
Seed starting mix should be free of pathogens, so your new plants aren’t killed by disease. Some seed starting mixes include fertilizer, while others do not.
Potting soil is to fill pots for both indoor and outdoor container gardens. The intention of potting soil is to hold more mature plants that are past the seedling stage.
Potting soil has a more airy texture than garden soil so that roots can develop freely, and the weight of the container remains light enough to move. Potting soil will often include slow-release fertilizer, organic material, and vermiculite or perlite to aid in soil nutrition and aeration.
Most potting soils are too dense to allow sprouting seeds to push through the surface, which is why it’s not recommended for use as a seed starter unless the label specifically states otherwise.
Do You Really Need Seed Starting Mix?
Every gardener will admit that they start seeds with whatever soil they have on hand at one time or another. Sometimes the plants grow well, and sometimes they never germinate.
The benefits of using a seed starting mix include:
- Sterile mix prevents disease and pest issues that kill off seedlings
- Fine texture with plenty of aeration for optimal root and sprout development
- Provides better and more consistent moisture control and pH levels
- Saves money – more seed germination means more plants
- May have extra nutrients to boost initial growth
The pros of using a seed starting mix outweigh the extra cost, as you will have an increase in viable seedlings when you use it correctly.
The biggest mistake novice gardeners make is not adding fertilizer to seedlings once they develop the first set of real leaves.
Most seed starters provide zero nutrients and are a way to help seeds germinate. The mix is not meant for the long-term growth of a plant to maturity.
Features Of The Best Seed Starting Mix
To find the best seed starting mix for your needs, check out these important things to consider:
Look for a blend of natural ingredients like perlite, vermiculite, lime, peat moss, coconut coir, or diatomaceous earth in your seed starting mix. The materials will remain lightweight, hold moisture, and prevent compaction so seeds can germinate and grow without wilting off.
If you want to keep an organic garden, look for a seed starter with an OMRI listing, which deems all the ingredients safe from synthetic chemicals that could be harmful to the plant, people, land, or waterways.
The seed starting mix’s texture should be fine and almost fluffy, which allows air pockets to form that increase oxygen flow to delicate roots and allows them to spread without straining against heavy, compacted soil.
If you want to keep your seedlings in the same growing pots for several weeks or months, look for a seed starting mix that includes a fertilizer. This type of mix feeds plants as they transition out of the seedling stage, so you won’t have to closely monitor them as you would with a non-fertilizing seed starting blend.
Some plants need a specific soil acidity to germinate and thrive. Most seed starting mixes aim to achieve a pH level safe for most plants in the 5.6 to 5.9 range. If your plant’s needs require something different, use a pH tester on the mix and add lime or another amendment to make it correct, or look for a blend labeled for that type of plant.
Seed Starting Mix FAQs
Can You Reuse Seed Starting Mix?
Recycling can be a good practice, but not when it comes to the soil you use to start seeds. As plants grow, so do the soil’s microbes, even if you start with a sterile medium. Because germination and seedling growth are delicate developmental stages, it’s imperative you give your plants the best possible start in life by using clean soil. Even if your seeds sprout in reused soil, it’s common for the seedlings to die off shortly after if there are pathogens in the dirt, which causes damping-off disease. I prefer to “recycle” my seed-starting soil by adding it to my compost pile. As the compost processes, it eliminates any harmful molds or fungi before I add the material into my outdoor gardening planters.
Is Coconut Coir Good For Seed Starting?
Yes, coconut coir is an excellent seed starting medium, as it’s free of pathogens that can attack delicate root systems. The coir also controls moisture better than a potting mix, as it retains enough to feed the roots but won’t get soggy and rot them out. Do be aware that most coconut coir contains NO nutrients, so if you aren’t transplanting your seedlings into soil that contains fertilizer, you’ll need to add liquid fertilizer to your plants as necessary.
Are Peat Pellets Good For Starting Seeds?
Peat pellets are a popular growing medium for seed starting. The biggest benefits of peat pellets are: Clean and simple to work with, Affordable and readily available, Holds moisture that releases slowly to the roots, Is naturally anti-microbial, which reduces fungal growth, Pellets hold their shape (and the plant roots) in place for easy transplant. Some gardeners love using peat pellets for starting seeds, while others prefer other growing mediums. The difference can depend on which plants you’re growing, the location of your seedling trays, your climate, and other factors.
Choosing a seed starting mix starts with your gardening style and requirements. Vegetables, flowers, succulents, trees, or shrubs have specific soils in which seeds will germinate best.
No time to sort out all the options? For general planting, I suggest starting seeds in the Miracle-Gro seed starting mix that provides immediate nutrition to growing plants so they can flourish.
Sprouting seeds in the best seed starting mix will reduce stress on your plants and allow them to put that energy into growing a durable root system, so give it a try and see the amazing results for yourself!