How to Choose the Best Seed Starting Mix

 

If you are going to go to the expense and effort of starting seeds, using the right seed starting mix will ensure healthy seedlings and strong transplants.  There are may DIY mixes, however, purchasing an organic seedling mix often saves time and maybe money.  You do the math. My favorite is Black Gold.  It's very fine, easy to wet, and produces healthy seedlings.  

Characteristics of a seed starting mix:

• Seed starting mixes are soilless this ensures that fungus such as damping off disease and other soil borne diseases are not a problem
• Seed starting mixes are non-fertile.  Within the seed are are the nutrients that an emerging seedling needs.  It's not until after the true leaves appear that you would fertilize your seedlings with a diluted liquid fertilizer such as fish emulsion.
• Seed starting mix are meant to hold water which penetrates the seed coat and along with the correct soil temperature begins the germination process
• Seed starting mixes are finer than a potting mix.  A good mix is well screened and fine allowing roots to easily penetrate the medium and allowing for good seed to soil contact.

What's in a good seeding mix?

Almost every seedling mix will have peat moss or coco coir as the base ingredient.

Peat Moss

Peat moss is mined from peat bogs in Canada and the Northern US.  Some consider it non-sustainable and opt to use coca coir.  Peat moss is very fine texture if it has been sifted and retains water remarkably when. 

Coco Coir

Coco Coir is the refined husks of coconuts.  It comes in compressed bricks.  It can be a slow process to rehydrate it.  I prefer peat based seedling mixes.

Vermiculite

Vermiculite is volcanic rock that is heated until it expands.  This light weight fine amendment is great at retaining moisture and holding nutrients. It provides less aeration but better water retention than fine perlite.

Perlite fine grade

Perlite is created when volcanic glass is heated causing the particles to pop forming little ball like particles.  Only use the fine grade perlite for seed starting.  Perlite provides drainage and aeration preventing compaction.

Coarse Sand

Only use sand if you need a heavy mix and better drainage.  It works well for larger seeds.  Look for builder's sand or all purpose sand.

Grit

Grit it not added to the seedling mix but some gardeners like to put it on the surface.

DIY Seed Seed Starting Mixes

If you enjoy creating your own mix.  Here are some ideas.

Basic Seed Starting Mix

1 part sifted peat moss

1 part vermiculite

*Better Drainage Mix (preferred mix)

1 part peat moss

1 part vermiculite

1 part fine grade perlite

Peat Free Mix

2 part coco coir

1 part vermiculite

1 part perlite

Seed Starting mix with High Drainage

2 parts pet moss or coco coir

2 part vermiculite

1 part coarse sand

You can premix these and keep in totes.  Scoop out the amount you need to wet.  I use a dish pan to wet the seedling mix.  You are then set to plant.  

When potting up plants add 1 part compost to the mix.