Home » Garden » What You Need to Know About Sowing Seeds Indoors

What You Need to Know About Sowing Seeds Indoors

Are you starting a flower or vegetable garden from seed this year? Here’s what you need to know about sowing seeds indoors and what I learned along the way.

If you’ve been following along my seed starting journey, today we are chatting all about sowing seeds indoors.

In case you missed Parts 1-3 of this grow with me series:

And today is the day we begin sowing seeds indoors. I am so excited to start growing new plants!

So let’s get started.

(Posts on stacyling.com may contain affiliate links. Click HERE for full disclosure.)

How to Start Seeds Indoors Without a Greenhouse

Sowing Seeds Indoors

Before beginning, read the seed package for sowing directions in case there’s anything you need to do beforehand.

I am starting sweet peas and it is recommended to soak them for 24 hours before sowing. Each seed variety may have their own requirements so prepare yourself ahead of time.

When you are ready to begin sowing seeds, here’s what to do.

  • Gather your seed starting supplies. If you don’t have a greenhouse like me, find a location in your home where you have room to work. I am sowing my seeds in the kitchen and will move the trays to the basement when finished.
  • Fill each of the cell or pots with pre-moistened seed starting soil. Pack it down to remove any air bubbles and gaps.
What You Need to Know About Sowing Seeds Indoors
Pack pots with pre-moistened seed starting soil.
  • Sow seeds according to seed packet directions. How deep you sow will depend on the seed variety. As a general rule, plant seeds twice their depth. For sweet peas, I used a pen to make a small hole and followed my good friend Kim from Shiplap and Shell’s advice to sow 2 sweet pea seeds at opposite sides of the pots. (Note: make sure you sow only one type of seed variety per tray because they germinate at different rates.)
  • Drop seed in hole then back fill with vermiculite. Depending on the type of seed, drop 1-2 seeds into each hole until the tray is completely full. It’s OK to cover with seed starting soil, but vermiculite is easier for seedlings to grow through.
What You Need to Know About Sowing Seeds Indoors
For sowing sweet peas, I used a pen to make the hole. Read all seed packet directions for sowing depth.
  • Label your seed trays and/or individual pots.
  • Cover seed trays with plastic dome.
  • Place trays on heat mats under grow lights. If you have a greenhouse like my friend Kim fro Shiplap and Shells, follow what this method.
What You Need to Know About Sowing Seeds Indoors
Drop seed in hole.
  • Set lights to be on for 14-16 hours per day. Using a timer works best for this.
  • Check seedlings daily for germination.
  • When seeds begin to sprout, uncover and remove from heat mats. Don’t worry if they didn’t all sprout because more will germinate after the dome is removed.
What You Need To Know About Sowing Seeds Indoors
Lightly cover with vermiculite.
  • Place trays under the lights and keep them fairly close – like an inch or so away from the tallest seedling. Keep any eye on seedling growth as you will need to adjust the lights while they grow.
  • Make sure you keep the soil moist and always water from the bottom. If the seeds aren’t in a tray that has a water reservoir, sit them in a tray of water for about an hour so they can soak it up from the roots.
What You Need to Know About Sowing Seeds Indoors
Cover with clear plastic domes and set on heat mats under grow lights.

3 Lessons I Learned From Sowing Seeds Indoors

  1. As much as I love using biodegradable pots, they stay really moist and grew a little mold around the outside of them. I’ve been cleaning them off and it’s disappearing, but I will just use recycled and re-usable plastic moving forward. It’s less risky.
  2. Because I am only sowing one seed variety per tray, I should have bought more seeds of that same variety or would only need to use 36 cell trays vs 72 cell trays. Since my suburban garden can only fit so much, I bought only one seed packet of each variety.
  3. Turn heat mats around so the cord hangs down in the back of your shelving. Seems kind of obvious, but apparently not to me. I was so excited to start and get my sweet peas on the mats that I set it up without really thinking about it. So I’ll fix this with the next set of seeds that I start.
What You Need to Know About Sowing Seeds Indoors
Remove clear plastic domes and take off heat mats after germination. Here’s my first sweet pea!

Watch It on YouTube

Check out my video demonstrating how to sow seeds indoors without a greenhouse.

Click on the video below to see the live action.

YouTube video

And be sure to subscribe to my YouTube Channel so you don’t miss my gardening how to’s, home and garden tours and latest DIY projects.

All About Sweet Peas

While my sweet peas are off to a good start, I hope I am successful with them in the long run. They are so beautiful and I am so excited to try something new in the garden this year.

Since I’ve never grown sweet peas before or started them from seed, I am learning so much about them from my good friend Kim from Shiplap and Shells.

You can read what she advises about them HERE.

Sweet Peas Photo by Shiplap and Shells

What’s Next?

Now that my sweet peas are sown, next on my list are Iceland poppies and snapdragons.

I’ve read that Iceland poppies are a little more advanced, so we’ll see how they do.

Wish me luck!

In addition to sweet peas, my friend Kim also has a great post about how to snow snapdragon seeds indoors too! I’ll be using her tips and tricks while sowing my snapdragons this weekend.

Happy Gardening!

Snapdragons Photo by Shiplap and Shells

Want To Get More Organized to Start Seeds?

CLICK HERE to get my FREE DOWNLOADABLE PRINTABLE that will help you get organized to sow seeds this year.

Print as many pages as you want and add to your gardening journal for ease of reference during the growing season.

How to Start Seeds Indoors Without a Greenhouse Series

Shop for Seed Starting Supplies

Pin and Save It For Later

If you like this post, please share and pin it on Pinterest. (If you hover over the image, the Pinterest button will be in the upper left corner.) I’ve created the below-custom pins for this post.

What You Need to Know About Starting Seeds Indoors
What You Need to Know About Starting Seeds Indoors
What You Need to Know About Sowing Seeds Indoors

Subscribe to the blog and gain access to information not available to the general public.

Thanks for stopping by the blog today!

Enjoy your day! xoxo

If you like this post, please follow me @bricksnblooms on Pinterest, Facebook, Instagram, and TIk Tok. Subscribe to my YouTube Channel. Or join my Facebook Group.

Leave a Reply

Your email address will not be published.


  1. You are always giving such great info, especially for newbie seed planters, like me! Thanks for sharing your knowledge!

  2. I love your blog post Stacy! You share so much great information. Thank you so much for including my sweet pea and snapdragon seed posts. Love teaming up for these!

    1. They are such great posts! I had no idea it was better not to cover the snapdragons with the dome. I’m so glad you wrote it! xoxo

  3. Pingback: Friday Favorites at The Farmhouse - The Everyday Farmhouse