Planting Seeds Indoors – Gardening 101

When it comes to starting your garden, you have a couple of options, you can either buy plants already established or plant your seeds indoors. If you are interested in seed starting, then in today’s post, I am going to show you seven steps to start your seeds indoors. So let’s begin.

If you saw my last post, “Cranberry Vintage – Early Spring Cleaning.” I shared our plans for the upcoming season. One of the projects mentioned was starting seeds, and that is what we are going to work on today.  

4 Reasons for Planting Seeds Indoors  

Seed Packet Examples
Take time out to review your seeds.

Here in St. Louis, I like to start some of our seeds indoors for a few reasons;  

  1. We have a short growing season.  
  2. It’s a lot cheaper than buying individual plants.  
  3. We have more control over the quality.  
  4. You can get a wider variety of seeds to grow.  

The Best Time to Plant Seeds Indoors?

When it comes to starting seeds, you typically want to start before your last spring frost date, depending on the plant.   

What Seeds Are We Growing?  

We will focus on starting seeds for vegetables such as peppers, Brussel sprouts, cauliflower, cabbage, tomatoes, broccoli, swiss chard, and a few other plants.   

Let’s talk about seeds in the materials you will need before we get into the seeding steps.  

Plant Seeds & Seed Life  

When you’re starting seeds indoors, they can come in various shapes, sizes, weights, and brands.  

You can buy them in bulk from places like Johnnys Selected Seeds, or if you are brand new to growing or have a small space, you can buy them from your local home improvement store like Home Depot.  

This year, we decided to purchase a few new seeds and reuse some older ones from past years. The perk about using smaller packages is that you have more control over the number of seeds, and whatever you don’t use, you can save till next year. If you decide to reuse old seeds, that’s fine because some can last longer than a year.  

Each package has a description and instructions on the back of the packet. It contains information to follow when germinating your seeds.  

For the sake of this video, we are not going to get too deep into this topic; however, if you want to learn more about reading a seed packet or if you can use old seeds, check out these videos or click on the links in the description below.  

Organizing Your New Seeds  

 Taking time out to organize your seeds first will make the process a lot easier. For instance, I like to sort out mine based on;  

  • The plant family, such as spinach, carrots, tomatoes, etc. 
  • If we should start them indoors or outdoors.  

When it comes to storage, I don’t have anything super fancy. My setup consists of simple sandwich bags and clear plastic containers with lids.  

Sprouting Materials 

 Now that we have covered the seeds let’s talk about the materials we will need to start planting seeds indoors.  

One thing to know is that when you are starting to grow your veggies from seeds, you don’t have to go broke in the process when getting the setup together.  

Last year, when I first started seeding, I use the bare minimum in my setup; a shelf, photo lights, and seeding materials. Since then, I have learned a lot to the point that I am now upgrading my design slightly.  

This season, I am going to use the following materials (I will provide a link to purchase the resources in the description below as well):  

  • Plastic Zip Lock Bags  
  • Plastic Containers  
  • Hydrogen Peroxide  
  • Old Bowl and Spoon  
  • Spray Bottle  
  • Permanent Markers  
  • Starter Trays  
  • LED Lights  
  • Tools  
  • Seed Starting Soil  
  • Labels  
  • Shelving  
  • Gloves  
  • Worm Casting Soil  
  • Heat Mat or Warm Area in the Home 

Now that we covered everything let’s get started with seeding our veggies and herbs.  


Review your seeds: 

Seed Packet Examples
Take time out to review your seeds.

The first thing you want to do is take out time to read your seed packets to determine the proper way to start your seeds. The package will tell you things such as;   

Are the seeds best started indoors or outdoors?   

Do you need to soak, scratch, or chill the seeds before planting them?   

What is the preferred temperature for germination?  

If you need help understanding what information is on a seed packet, check out my post “Vegetable Seed Packets – Info You Should Know.”

Prepare and Disinfect Your Trays: 

When you prepare and disinfect your seed trays, it prevents necessary fungus and bacteria from forming in the cells. Taking steps to clean and disinfect your materials doesn’t eliminate the chance of bacteria or fungus developing; however, it does lessen its occurrence. To give you an idea, here are a few steps that you can take to clean your materials;  

If you’re reusing old seed trays, make sure that you remove any remaining soil from the previous year.  

Rinse out remaining debris and clean the trays with warm soapy water.  

Spray the trays with hydrogen peroxide.  

Once sprayed, then you let them sit to dry for at least 20 minutes.  

Prepping Your Soil and Starter Trays: 

Now that you have prepared your seed trays now we can move on to prepping the soil. You can buy the soil already premade, just like the ones we’re using. This year, I am going to add worm casting to my soil as well. Buying the seed starter or coconut core is a good start; however, I still like to take additional steps to ensure that the soil is ready to go.    

Mix the starter soil with worm casting soil.   

Dampen your soil with warm water. You want the temperature to be around 70 to 75°F because that’s what most seeds will need to germinate.  

Ensure that your seed trays have the proper drainage holes in the cells before you apply the soil. Next, fill the cells with the soil. Push down the mix to make sure the soil is compact, then add more until it’s almost full.   

Add the New Seeds: 

When you add seeds to the soil, make sure that you sow them based on the cultivator’s recommended depth.  

As you plant the seeds in each cell, make sure that you add up to 3 to 4 extra seeds in each cell. Doing so will help with potential seed failure just in case some seeds don’t germinate.  

Once the seeds in the soil, add a thin layer of soil on top.  

Afterward, lightly water the tray and cover it with the plastic lid that comes with the seed tray. If you do not have a plastic cover, you can use plastic wrap.  

Keep the seed trays covered until the seedlings appear. During this time, you don’t need the lights; make sure that you keep the seeds warm and maintain moisture.  

Hey! If you are starting the season off with old seeds, check out my post called “Old Vegetable Seeds – Are They Still Good?”

Transition the Seeds to Artificial Light: 

Once the seeds sprout, it is time to move them to the shelf’s LED lights. When it comes to the stand, it doesn’t have to be anything fancy. It just has to be able to hold your trays and the LED lights. In our case, we are using a metal shelf that we have had for a few years now.  

Remove the plastic, and place the lamp at least 1 to 2 inches away from the plant.  

As the plant grows, increase the light distance as needed.  

Keep the light on the plants for up to eight hours. You can manage the time by investing in a search protector with a timer on it, such as this one.  

Once the seeds grow to about 3 inches informed true leaves, separate them into larger pots if necessary.   

To maintain moisture, water the trays from the bottom and drain any excess water.  

After about 4 to 6 weeks, begin the transitioning of hardening of the plants so they can go into your garden.  

Transition Seedlings to Natural Light: 

Transitioning Seeds for Planting

As your seedlings start to grow bigger, it’s time to introduce them into nature. It’s important to harden them off to have time to adjust to the conditions outside, such as wind and sun. When you introduce your seedlings to natural light, it’s best to start training them two weeks before planting outdoors.  

Start leaving your seedlings out for a couple of hours a day and bring them in at night.  

Increase the time until the seedlings can sit out all day.  

Once a few weeks have passed, your seedlings should have successfully adjusted to being outside, and it’s time to either transition them into larger pots or put them into the garden.  

Plant Your Seeds Outdoors: 

Once the hardening process is complete. Now you can transfer your plants into your garden.  

Make sure that you transplant them on a cloudy day or late afternoon to prevent damaged plants.  

As you transition seedlings into their new setting, make sure you let the root ball seeds and not by the stem.  

Once they are outside, continue to water them and treat them as needed.  

After a few weeks, you should have a beautiful plant or some fresh vegetables and fruits coming in!  

And there you have it! We have just gone through seven steps to starting seeds indoors. Hopefully, you will have some beautiful veggies ready for your garden in a few weeks.  

With that being said, have a fabulous day and stay supertastic!  

Thank you for reading my post, and if you have not already, feel free to subscribe! For those interested in a video version of these questions, check out my YouTube video below.

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