When the time comes to start seeds indoors for your vegetable garden, you’ll need a light system, trays or pots and a seed starting medium. Indoor seed starting is never done in garden soil, which is too heavy for seed starting and might carry diseases. Instead, gardeners usually choose some kind of seed starting mix.

What’s in these mixes? As we noted in a post last year, most seed starting mixes include peat moss or coconut coir for nutrients and water retention, perlite or vermiculite for lightness, and some kind of compost, humus or other fertilizer for nutrition. The moss or coir and the perlite or vermiculite work together to provide a light mixture that allows the seeds to easily send their roots out, while the compost feeds the plants. The ratios of these components vary widely, from a mix that is 50 percent or more compost to ones that are only 20 percent compost.

Seeds don’t need the nutrients from compost to germinate — the seed has everything inside it except water and air. But once the seedlings begin growing some compost or other fertilizer is necessary. In the past, I’ve hard great success with a mix that was 2 parts peat moss, 2 parts vermiculite or perlite and 1 part worm castings.

What’s your favorite seed starting mix?