Starting Tomato Plants From Seed

If you are looking to start tomato plants from seeds you are in the right place. Get step-by-step help that you can use to start a backyard garden with amazing organic plants you started from seeds.

It’s that time of year up here in Northwestern PA it’s seed starting time for our summer gardens. Yes, it is officially time to get those seeds into their growing trays so our plants are the right size come Memorial Day or planting day wherever you live. Up north, Memorial day is when we are pretty safe to put our plants out into our gardens. Since our growing time is shorter than our southern friends we need to get a jump on things by starting our seeds indoors. If you have not yet tried your hand at starting tomato plants from seed it’s so much easier than you think.

And it’s a great way to start a garden from scratch and really ensure you know the exact source of your food.

 How to grow tomato plants from seeds

Where I live a flat of tomato plants can cost around $18. Whereas a packet of good seeds cost about $3 and the organic seed mix is usually under $5.

Two packs of seeds and a bag of dirt will give you about 2+ flats of plants if not more.

So you can see right off that growing your own plants is a cost saver of about $28.00. Just another reason why you should give this a try!

Before we dive into starting plants from seed, there are a few things you will need to have first. 

1. First,  you will need a place to grow your young plants or seedlings. A place that is warm (although it’s not a requirement) and one that is out of the way of tiny hands and nosey pets. 

2. Next, you will want a stand of sorts to hold your flats of delicate plants. Yes, you can purchase stands and pretty elaborate growing systems. But I like to do things on the cheaper side and try to reuse what I have on hand before heading out to the store to buy. If you have a shelf that you are not using or a table that you can repurpose this would be a great project for them. Look for something that is sturdy and can hold a few flats of plants.

The goal with the stand is to create a greenhouse of sorts where you can contain the warmth and the dampness giving the perfect growing environment for young seedling plants. 

Click here to subscribe

How To Start Tomato Plants From Seed

Step #1  Gather your containers.

You know those plant containers your plants come in? Well, never EVER throw those out. They are more durable than you think and perfect to use when starting your new batch of seedlings.

I believe I am in my 10th year with these containers and they are still holding strong.

I also have the trays the plants came in which are really convenient when you are moving from inside to outside.


They are also great for keeping water from dripping all over your floor when you are watering.

a stack of seed flats and soil on a counter

Step #2  Start with a good soil mix.

When starting tomato plants from seed the key is to use good quality starter soil.

I prefer to use an organic seed starting mix, although I have used others with good success. I just like the quality of this mix and have always had great luck with it. Remember if you want strong and healthy plants then you need to start with good quality soil. This will give your seedlings the environment they need to grow strong and sturdy root systems. Root systems are the key to healthy plants and help your harvest to be a bigger and more abundant one. 

The good news is, it is surprisingly inexpensive to purchase organic seed mix and it is sold just about everywhere both online and in stores.

Step #3  Clean and sanitize your containers. 

If you choose to reuse planters as I mentioned above you will want to wash and sterilize them before using them again. This will remove any old soil and possible pests or lingering diseases from previous years. I like to use a bottle brush (bought from the dollar store) and warm soapy water with a bit of bleach added in.

Wash each one, rinse well, and stack on a large towel to air dry. If it is a sunny day, you can allow your containers to dry in the sunshine. The sun acts as a natural sanitizer and is a great way to dry things up rather quickly. 

cleaning supplies, bleach, gloves, brush and bucket used to disinfect seed planters

Make sure to wear gloves so the bleach does not irritate your skin. The ratio I use is about 1 part bleach to 9 parts water. I usually just fill a bucket and pour in a little bleach eyeballing the measurement.

Your goal here is to remove any disease, if there is any, before planting your seeds giving them the very best environment to grow in early on. 

Step #4  Prepare your soil.

One of the best tips I can pass on to start plants from seed is to make sure you presoak your starter mix.

I have tried to plant my seeds without presoaking and they took forever to sprout setting me back a full week on my schedule. The seed mix is made to hold in moisture giving your seeds the perfect foundation for growth.

But adding water to seed starting mix is tricker than you might think. That’s because the main ingredient in most seed starters is peat moss. Which can be loose, lightweight, and rather dusty. To soak your soil you will need a large container like this washtub I found again, at the dollar store.

dish of soil used to start plants from seed for an organic garden

How to Soak Seed Starter Mix

Pour in some mix into your container and add a generous amount of water. I like to use the spray nozzle on the hose at my kitchen sink. This allows me to add water more evenly over a larger area.

Next, take a large wooden spoon and work that water into the mix. Continue doing this until the soil is thoroughly damp yet not soaked.

SLCG PRO TIP: If you accidentally get it too wet you will want to let your soil sit for a day or two to dry out. Be sure to mix a few times throughout the day to help it dry more evenly.

Once the soil is to the right consistency (damp but not wet) it is ready for planting your seeds. 

Step #5  Plant your seeds.

When planting your seeds please be sure to follow the instructions on your seed packets.  The actual time you plant your seeds will all depend on the zone you are in and when you are able to transplant your seeds outdoors. You can find your zone here. Usually, you want to start your seeds indoors approximately 6-8 weeks before the last frost of spring in your area. 

tiny tomato seedlings growing in a flat filled with soil

SLCG PRO TIP: Once you have your zone number and frost date you can add this to your garden planner. A garden planner is a crucial part of any gardener’s library. This is where you will journal your growing season year after year. A garden planner is a great way to ensure you are always improving as a gardener and learning from past growing seasons. 

Begin by putting a layer of soil into each container of your seed flat. Using your fingers lightly tamp down the soil without compacting it. Next place 2 seeds per pot to ensure the growth of at least one plant. If both seeds take, you will need to pull one of the seedlings out later so that all the water and nutrients in the soil will be focused on just one plant. This will help the remaining plant to grow a strong root foundation that is important for an outdoor garden. 

Once all the seeds are dispursed cover them with a layer of soil. Again you will want to tamp down the soil lightly over each seed. As the dirt settles you can add in additional soil as needed. For this purpose, I usually keep damp soil ready for the first few weeks so I have a supply that is damp and ready to add in if needed. 


A flat of soil waiting to be planted with seeds

Step #6  Set up an indoor growing system.

The great news about setting up a growing system is anything at all will work. You just need an out of the way place that is relatively warm and somewhat protected. Shelves work great if you have them available. This means there is really no need to invest in an expensive growing “ready for you” set up if you do not want to. 

When I first began growing my own seeds I used a table in my craft room. I placed my flats under the table so they were out of the way while I was crafting and suspended my lights from lightweight chains attaching them to the sides of the table. 

The lights I use are 4 feet long and are the perfect size for a flat of plants. If the area of the home is warm normal bulbs will usually give off enough heat allowing your plants to grow well.

flats of plants growing under lights below a table.

If you are growing your plants in a colder area such as a basement where things can get quite cool you will need to do a bit more to keep your delicate seedlings warm enough to grow. You can use inexpensive plastic sheeting to wrap around your growing area. This will help to keep any warmth inside with your plants, turning your growing area into sort of a makeshift greenhouse. 

Your goal is a constant temperature of 65-75 degrees. You can place a thermometer inside of your setup and monitor the temperature daily. 

Step #7  Water gently and correctly.

In the first few days, you will not need to water much if at all, since you already dampened your soil before planting. When you do begin to water your seeds, I suggest using a disposable water bottle. I find I can control the amount of water much better with one and there is less risk of drowning the seeds. Remember to water gently giving just enough without saturating them.

Once the young plants have sprouted you can then switch to a spray bottle. This will water your delicate seedlings without crushing them. It is so important not to overwater, especially in the beginning.  If you are not sure, just check the soil with your finger. Gently feel the soil, if it’s wet, don’t water.

Depending on the type of seeds you plant you should see something sprout at about 6-8 weeks. If after 10 or 12 weeks you still see nothing breaking through the soil, then I would assume the seed did not take. Please refer to your seed packet to verify that you have given your seeds enough time to sprout. If your temperatures are not warm enough it may take longer for your plants to break the soil’s surface which is something to keep in mind. 


Step #7  Add more soil. 

You may notice after the first few days the seed mix begins to settle a bit. This is normal and will happen a few times in the beginning. This is a good time to add more soil lightly covering each seed as you see they need it. Remember to make sure that the soil you are adding is damp but not soaking wet. 

Step #8  Thin your seedlings. 

This is always the hardest part for me.

Remember in step 5 I told you to put 2 seeds into each planter? Well if you notice that you have 2 or even 3 sprouts inside of one growing section you will need to remove all but one.

Choose the strongest seedling to keep and gently remove the extras. The best way to do this is to use your finger to gently hold the base of the seedling you are going to keep. You can then slowly and safely remove the other seedlings. Grab the seedlings you are removing with your free hand and gently pull them out holding the other seedling in place. 

tomato seedlings in a flat

SLCG PRO TIP:  If you had seeds that did not sprout and now find you have empty seed containers you can try to transplant the removed seedlings there. They may not take but I have found more often then not, they do! 

Step #9  Hardening up your plants.

As it gets closer to planting time, see here for dates in your area, you will want to begin hardening off your plants.  That just means getting them acclimated to the weather so they are better able to withstand the fluctuations that tend to hit in the springtime. This is especially important if you live in a cooler climate as I do.

To harden off your seedlings, take your planters outside on a sunny and preferably windless day and let them soak up the rays of the sunshine. Try to keep it short and sweet in the beginning so you do not damage your plants. As the seedlings strengthen up you can increase the time longer and longer. 

Click here to subscribe

Step #10. Transplant your seedlings into your garden. 

This is the most exciting time for gardeners, getting those new plants into your summer garden. Be sure to space your tomato plants appropriately and use sturdy stakes or cages to keep them growing strong all season long. When setting up your garden, location does matter. Tomatoes love sunshine so choose an area that gets 6-8 hours of sun a day.  

I prefer to garden in raised beds. This allows me to grow more in a smaller area giving me the most harvest year after year with less work. Raised beds are also easier to keep weeded, watered, and safe from predators such as rabbits and dear. 

If you don’t have a garden, don’t worry, you can grow all you need right on your front porch using buckets, pots, and other containers. 

Read:  How to Grow Tomatoes in Pots – A Step by Step Guide.

Starting tomato plants from seed is not only economical but easy and fun as well. I just marvel each summer as we enjoy those beautiful tomatoes that all started from a tiny little seed. Try your hand at it this year so you too can enjoy the fruits of your labors come summer.

Be sure your plants have the best organic start they can, start those seeds at home! Learn how to start beautiful tomato plants from a packet of seeds in your home and the best way to prepare them for your summer garden. #gardening #garden #gardeningforbeginners #homestead




  1. Great post! I’m usually starting seeds as well but we’re anticipating a move so I’m not going to be starting any. thank you for sharing your post on Our Simple Homestead Hop, as one of the co-hots I will be featuring your post tomorrow! Look forward to what you’ll be sharing this week!
    -Nancy ( Nancy On The Home Front )

    1. Hi, Nancy,
      I am so happy you enjoyed it and that it will be featured. You just made my day!
      Thanks for stopping by! Good luck with your move. 🙂
      Tracy Lynn


    1. Hello, Vincent.

      Yellow plants could be a few things. Too much water for one. Make sure the soil is moist but not soaked. Another is not enough light. If you have your plants under grow lights, maybe raise them up by stacking a few books underneath.
      Those two things should fix them for you!
      Tracy Lynn

  3. Suggestion: If you have more plants per pot then wanted or needed, don’t pull the extras out. Instead, cut them off with scissors so you don’t disturb the remaining plant.

Leave a Reply

Your email address will not be published. Required fields are marked *

This site uses Akismet to reduce spam. Learn how your comment data is processed.