The Best Seed Starting Mixes

Hello, my friend, hello again; today we come together to talk about The Best Seed Starting Mixes and hope the blog can help you.

Giving flowers and vegetables a head start with seed saves money and offers gardeners a wider selection of plants. To increase your odds for success, use a growing mix designed especially for seed germination.

When the weather warms, gardeners often head outdoors to sow quick-sprout vegetables, such as cucumbers, squash, and tomatoes. Starting seeds indoors is also a rewarding, economical way to get a jump on the gardening season, but it can be tricky.

To reduce the risk of seedling failure, you need to use the right medium: an uncontaminated grow mix, instead of any old soil. The best seed-starting mix is clean and lightweight, and it offers an optimal foundation for seed germination. Read on for some of the top seed starting mixes available today and some things to keep in mind while you shop.

1. BEST OVERALL: Espoma Organic Seed Starter Premium Potting Soil Mix
2. RUNNER-UP: Hoffman Seed Starter Potting and Planting Soil
3. BEST BANG FOR THE BUCK: Miracle-Gro 8-Quart Seed Starting Potting Mix
4. BEST WINDOW KIT: Window Garden Mini Greenhouse Seed Starter Kit
5. BEST COMPOST-BASED: Purple Cow Organics Natural Compost Seed Starter Mix
6. BEST ORGANIC: Coast of Maine Sprout Island Organic Seed Starter
7. BEST COCONUT COIR: Burpee Organic Coconut Coir Seed Starting Mix
8. BEST STARTER PELLETS: Jiffy-7 36-Millimeter Peat Pellet Seed Starter Plugs
9. BEST FOR HYDROPONICS: Urban Leaf AeroGarden Compatible Grow Sponges
10. BEST PEAT-FREE: SpongEase Pro Coco Coir Brick

Before You Buy Seed Starting Mix

Before spring arrives, garden centers begin stocking large bags of growing medium, but don’t grab one without reading the label. Growing mixes come in various blends, some designed to amend outdoor garden beds, while others are for potted plants. Still others contain fertilizers for specific plants, such as “acid-loving” or “indoor.” Along with standard potting soil, most of these options are not suitable for starting seeds because they contain some contaminants. Choose a mix labeled for starting seeds to ensure it doesn’t contain traces of fungus or bacteria that could wipe out tiny seedlings.

How We Chose the Best Seed Starting Mixes

We researched the most sought-after seed starting mixes in their respective categories and discovered that the best options are determined by their ingredients, form, quantity provided, and other special features included by top brands.

While searching for the best seeding mix available, the most effective and popular types among users for outdoor and indoor plant growth were potting soil mixes, pods, and sponges. These mixes included coconut coir, sphagnum peat moss, perlite, fertilizer, wetting agents, and even compost.

The seeding mixes allow for drainage, water-retention, root cutting, and transplanting while young seeds begin to grow. Many come with large quantities of up to 16 quarts or 50 pods or sponges. Plus, the majority of these picks are 100 percent certified organic seed starters.

Our Top Picks

To qualify as a top pick, a seed-starting mix should be lightweight, contain ingredients that retain moisture, yet drain well, and be free from harmful contaminants. The following products are better suited to some situations than others, but each seeding mix provides an optimal environment for germinating seeds.

Best Overall

Espoma Organic Seed Starter Premium Potting Soil Mix

Espoma’s organic seed starter mix contains all-natural ingredients, including sphagnum peat moss, peat humus (a decomposed ingredient from peat bogs), perlite, and Myco-tone, a proprietary blend of ingredients designed to help seedlings develop strong roots. This premium seed-starting mix retains moisture without compacting. Its all-natural formula helps when rooting cuttings, and it produces healthy plants with abundant blooms, making it well suited for both flowers and vegetables. This potting mix comes in an 8-quart or 16-quart bag.

Product Specs

• Ingredients: Sphagnum peat moss, perlite, limestone to adjust pH, and yucca extract
• Quantity: 8 or 16 quarts
• Organic: Yes

Pros

• All-natural potting mix for start seeds and root cuttings; helps improve moisture retention
• Noncompacting; intended to promote better root growth; also suitable for vegetables and flowers

Cons

• Some users who used this product have reported poor growth with some plants

Get the Espoma seed starting mix at Amazon or TrueValue.

Runner-Up

Hoffman Seed Starter Potting and Planting Soil

This seed-starting mix from Hoffman, which comes in a 4-, 10-, or 18-quart bag, contains Canadian sphagnum peat moss, vermiculite, limestone (a pH adjuster), and a wetting agent. The mix retains moisture while providing a light, airy growing medium that promotes seed germination and root development. Also use this seed-starting mix to root cuttings and in larger containers when transplanting seedlings. Ground limestone makes this mix work as a potting soil and for acid-loving plants, such as hydrangea or blueberries.

Product Specs

• Ingredients: Sphagnum peat moss, vermiculite, limestone, and a wetting agent
• Quantity: 4, 10, or 18 quarts
• Organic: No

Pros

• Lightweight, loose, and fertile soilless mix; specially formulated to promote seed germination and root development
• Contains 6 components blended in proper proportions; can be used for fruits, vegetables, and flowers
• Also suitable for root cutting and transplanting; absorbs water well

Cons

• May take some time to fully germinate some seeds, leading to a slower sprout

Get the Hoffman seed starting mix at Amazon or Kmart.

Best Bang for the Buck

Miracle-Gro 8-Quart Seed Starting Potting Mix

From a manufacturer well-known in the gardening industry, this Miracle-Gro potting mix is specially formulated to boost root development. Miracle-Gro contains sphagnum peat moss, perlite, fertilizer, and a wetting agent. The mix helps retain moisture and drains well, and it won’t pack down.

The included fertilizer contains nitrogen, phosphate, and potash to help stimulate sprout growth, root development, and blooms. This Miracle-Gro product, which comes in an 8-quart bag, is suitable for starting root and leaf cuttings as well as seeds. Also use it in larger containers when transplanting.

Product Specs

• Ingredients: Sphagnum peat moss, perlite, fertilizer, and a wetting agent
• Quantity: 8 quarts
• Organic: No

Pros

• Enriched with Miracle-Gro Plant Food; formulated to boost root development
• Good choice when starting from seed or starting plants with leaf, stem, or root cuttings

Cons

• This seed starting mix is intended for container use only
• Some users report a sour smell out of the bag

Get the Miracle-Gro seed starting mix at Amazon (2-pack), Ace Hardware, The Home Depot, Lowe’s (2-pack), or Tractor Supply Co.

Best Window Kit

Window Garden Mini Greenhouse Seed Starter Kit

This Window Garden seed-starting kit features three grow trays that are small enough to fit on a windowsill. Each tray comes with 10 compressed coconut coir grow pods. A clear dome sits atop each tray to act as a mini-greenhouse and help keep the pods from drying out.

Put the fiber soil pods in the bottoms of the trays and add warm water; the pods will expand and become light and fluffy. Each pod contains only organic coconut coir. When the seedlings are ready for transplanting to garden soil, insert the entire pod in the garden.

Product Specs

• Ingredients: 30- to 36-millimeter fiber soil (coconut coir)
• Quantity: 3 trays with 10 cells each (30 cells total)
• Organic: Yes

Pros

• 3 mini greenhouses are reusable; create a moist, warm environment needed for reliable seed germination
• Have a better root system, capable of absorbing more oxygen, moisture, and nutrients
• New plants can be transplanted directly into a garden or planter

Cons

• Pricey compared to other seed starter kits on the market
• Seeds are not included with this kit and must be purchased separately

Get the Window Garden seed starting mix at Amazon or Bed Bath & Beyond.

Best Compost-Based

Purple Cow Organics Natural Compost Seed Starter Mix

Purple Cow Organics’ seed starter mix contains sphagnum peat moss, perlite, vermiculite, and natural compost derived from yard trimmings. It also includes an all-natural blend of trace minerals and nutrients to boost plant health, promote rapid germination, and encourage strong, sturdy seedlings.

The mix is lightweight, offers moisture retention, and provides aeration for tender roots to develop. The activated compost provides added nutrients to feed young plants for up to 45 days. Although the mix bears the name Purple Cow, it contains no manure, and it comes in a 12-quart or a 1-cubic-foot bag. It is intended for seed starting in trays, blocks, or small containers.

Product Specs

• Ingredients: Natural compost, sphagnum peat moss, perlite, vermiculite, rock and sea minerals, fertilizer
• Quantity: 12 quarts or 1 cubic foot
• Organic: Yes

Pros

• Provides excellent moisture retention and aeration for increased germination and seedling vigor
• Includes fertilizer and trace minerals to add richness to garden soil
• Works up to 45 days; ample time for seeds planted in trays, blocks, or containers

Cons

• Some users report finding several small pebbles and sticks in this mix
• May be too chunky for proper seed germination with inadequate water retention to support growth

Get the Purple Cow Organics seed starting mix at Amazon or Target.

Best Organic

Coast of Maine Sprout Island Organic Seed Starter

This Coast of Maine organic seed starter contains a blend of ingredients designed specifically for starting seeds and root cuttings, including sphagnum peat moss, perlite, aged compost, kelp meal, and worm castings. The mix also contains an all-natural fertilizer to encourage growth and help produce disease-resistant plants.

Coast of Maine seed starter is a lightweight, well-draining growing medium that won’t pack down, so tender seedling roots can develop. It retains moisture to help prevent roots from drying out. The mix comes in 8- and 16-quart bags. There’s also a 2-cubic-foot option.

Product Specs

• Ingredients: Sphagnum peat moss; composted manure; mycorrhizae; fertilizer from poultry manure, lobster and crab shell, kelp meal, and worm castings
• Quantity: 8 or 16 quarts or 2 cubic feet
• Organic: Yes

Pros

• Designed specifically for germinating seeds and rooting cuttings to grow healthy, disease-resistant plants
• All-natural fertilizer made with rich ingredients, including kelp meal, worm castings, and lobster meal
• Lightweight garden soil that provides ample drainage and water retention

Cons

• Some users report poor consistency and mold; some say this mix attracts flies

Get the Coast of Maine seed starting mix at Amazon, The Home Depot, or Target (2-pack).

Best Coconut Coir

Burpee Organic Coconut Coir Seed Starting Mix

The compressed coconut coir in this seed-starting mix comes as an 8-quart, 7.25- by- 6- by-4-inch compressed brick. Just add water and crumble it to obtain 8 quarts of seed-starting mix. The Burpee Organic Seed Starting Mix contains only coconut coir and bone meal to help promote plant and root growth.

Once expanded with water, use the coir in any seed-starting container, by itself or in combination with potting soil to grow larger plants. The material retains moisture yet won’t pack down.

Product Specs

• Ingredients: Compressed coir soil and coconut husks
• Quantity: 8-quart
• Organic: Yes

Pros

• Compact size; when dry, this compressed brick is very easy to store
• Expands to 8 quarts of soil when watered; excellent water retention
• Ideal for seed starting; balanced pH improves nutrient absorption by seedlings or plants

Cons

• Tends to dry out faster than other mixes; needs more attention

Get the Burpee seed starting mix at Amazon, The Home Depot, or Burpee (2-pack).

Best Starter Pellets

Jiffy-7 36-Millimeter Peat Pellet Seed Starter Plugs

These Jiffy-7 peat pellets arrive in small, compressed discs but expand into fluffy grow pods when immersed in water. The pellets contain only compressed peat moss—nothing else. The user places a pellet in the bottom of a plastic flat or tray and pours in warm water to trigger expansion. When the expansion is complete, the pellet measures 1.5 inches by 1.5 inches, just large enough to insert a seed or two in the top of the peat moss.

The peat moss is held in place with a thin biodegradable net, and gardeners place the entire unit in the soil when transplanting to the garden or a larger pot. Buyers receive 50 compressed peat pellets per package.

Product Specs

• Ingredients: Compressed peat moss
• Quantity: 50 pellets
• Organic: No

Pros

• 50 pellets included, with each pod holding 1 to 2 seeds
• Pods are biodegradable, with less use of plastic; suitable for transporting

Cons

• Some users reported mold growth after planting seeds with these pods

Get the Jiffy-7 seed starting mix at Amazon or Grower’s Solution.

Best for Hydroponics

Urban Leaf AeroGarden Compatible Grow Sponges