How to Start Seeds Indoors

Step by step instructions on how to start seeds indoors. You’ll see seeds sprout in 3 days! Stop buying plants and start growing from seed!

small plant in seedling tray grown from seed.

What is the easiest way to start seeds indoors?

We start almost everything from seed indoors to guarantee a high germination rate and strong plants. The more control we have over growing conditions, the stronger we can make the plants so they are optimized for when they move outdoors to the garden.

You’ll need seeds, potting mix, water and (ideally) a heating mat. Below I’m going to walk you through step by step, but here you can see a quick video of me planting our Spring seeds.

Step By Step Directions to Plant Seeds

Buy your seeds. Everyone has their favorite brand, and I’m not here to coax you to what we like. But for reference we buy our seeds from Johnny’s Seeds, Vermont Bean Company and Baker Creek.

Look at the Calendar. You’ll want to start your seeds indoors weeks/months before you move them outdoors. Knowing when to plant them is very important so you don’t prematurely start them indoors (or start them too late!). Here’s my Northeast growing dates.

Potting Mix. Add potting mix to a seedling tray (on top of a growing tray). DO NOT USE SOIL, I REPEAT DO NOT USE SOIL. Potting mix is very light in texture allowing seeds to germinate easier. Soil is much heavier and seedlings starting out won’t like it.

After I add potting mix to the tray, I like to press it down, and then fill up the top again to make sure they’re completely filled.

hand spreading potting mix over seed trays

Poke holes 1/2 inch deep in the potting mix for your seeds. There are tools you can buy for this, but are you kidding me, just use your finger (my preferred method) or a closed pen.

hand poking holes in potting mix for seeds.

Add seeds to holes. We are confident that our seeds will come up, so generally we only plant 1 seed per hole. If you have older seeds or perhaps you’re beginning your lifelong love of gardening, try 2 seeds to be super safe.

Cover up holes with surrounding potting mix and pat down lightly.

Water from the bottom. Instead of watering the seeds on top, we prefer watering from the bottom. We add water to the bottom tray (about 1/4 inch deep). This way the water will rise into the seedling trays, soaking up the seeds, preventing them from drying out.

water coming out of sprinkler can into tray.

Move to heat pad. If you want 100% germination mat, invest in a heat mat for the best growing results (more about that below). Close the lid and move tray on top of a heat mat.

Look at your babies! Your seeds will start to sprout in 2-3 days.

How do you germinate seeds quickly indoors?

To germinate seeds very quickly indoors I recommend using a heat mat. By using a heat mat we’re almost always seeing a 100% germination rate. This is the heat mat we’ve used for many years.

Here’s my post on how we use a heat mat and thermometer for all of our seeds.

Do you need a grow light to start seeds indoors?

At the very beginning (the first few days where they sprout up from the surface) you don’t need a grow light. After that I recommend grow lights to ensure the strongest seedlings possible.

Here’s my post on how to make your own DIY grow light cart.