How to Start Tomatoes from Seed

Did you know that growing your own tomatoes from seed is fairly simple? I’m going to show you just how easy it is! Planting from seed not only saves you money, but the selection of tomato varieties is ginormous! Here is how to start tomatoes from seed.

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Deciding What Variety of Tomato to Plant

Not all tomatoes are the same. The very first step to planting tomatoes, is deciding what you want and why you want it. Once you make the decision to start your plants from seed, you’ll discover that the options of tomato varieties are a little overwhelming. And amazing!

Are you wanting tomatoes to eat fresh? Slicing tomatoes for your sandwiches, or cherry tomatoes for your salads?

Maybe you want to make tomato sauce? Or tomato juice? Fried green tomatoes? Salsa? Maybe all of the above…?

You will base your tomato varieties on your needs and wants.

Also, keep in mind that tomato seeds can last 4-5 years or more when kept in a cool, dry place. When buying a package of seeds, you may only need to use a few of them, and you can save the rest for future years.

The Difference Between Determinate and Indeterminate Tomato Plants

Another decision to make before planting tomatoes is to determine if you want/need determinate or indeterminate tomato plants.

A determinate tomato plant will grow like a bush, and only reach about 5 feet tall. It has a shorter growing season, and will set it’s fruit all at one time.

An indeterminate tomato plant is more vine-like, and can grow up to 8-10 feet tall. It will need to grow on a trellis type support. It has a longer growing season, and will produce more fruit over a long period of time.

Those who have a smaller garden space, or live in an area with a shorter growing season, may want to chose a determinate plant. Whereas someone who lives in a warm climate, with a long growing season, may want to opt for the indeterminate plant.

When to Start your Tomato Seeds

You need to start your tomato seeds indoors, 6-8 weeks before your last frost. You can look online to find out when the last frost date is for your area. Personally, I like to wait 2-4 weeks after the predicted date of last frost to transplant out my young tomato plants. Just to be safe.

(This is also the time to start pepper seeds. I have a post on that as well: Starting Pepper Seeds – 5 Simple Tips)

Items Needed to Plant Tomato Seeds

Chose a container to start your seeds in. It can be practically anything that you can poke a few holes in for drainage. You can use solo cups, plastic butter or sour cream containers, etc. Or I will list a few planting containers that you can purchase at the end of this post.

You may see some suggest egg cartons. Which you can totally use. But it’s such a small space, that you will need to transplant your tomatoes very soon after they germinate. Another drawback to such a small growing area is that it is very difficult to keep the soil moist. It dries out very quickly. So you’ll want to keep those things in mind when choosing your containers.

The next decision is your potting soil. Tomato seeds are very small and delicate, and cannot germinate well in a heavy garden soil. You’ll need a light and fluffy soil specifically for seed starting. Some bagged soils contain plant food, some do not. Either kind works. I personally use an organic seed starting soil, it will be listed below.

Another item that isn’t exactly necessary, but is very helpful, is a spray bottle for watering. Giving them water with a light mist from a spray bottle will help keep the seeds from sinking too deep into the fluffy soil. Make sure the bottle you use has only contained water or natural contents in the past, no chemicals. Or purchase a new one.

Lastly, you will need some way to label your containers. You can write directly onto the container you’re using, put a piece of tape on the container and write on that, label popsicle sticks, etc.

It’s Time to Plant your Tomato Seeds

Step 1. Moisten the soil.

I dump the estimated amount of seed starting soil I need into a 5 gallon bucket, add some water and mix it around. You wan the soil damp but not soaking wet. So start slow and continue to add water until you get it where you want it. When you can squeeze a ball of it together and it holds, but doesn’t drip water, it’s perfect.

Step 2. Fill Containers.

Fill the planting containers with your damp soil. Not quite to the top.

Step 3. Seeds.

Place 2-3 seeds on top of the soil in each container. Spaced apart slightly.

Step 4. Cover Seeds.

Lightly sprinkle an 1/8 of an inch of soil over the top of your seeds. Pat down gently.

Step 5. Warmth.

Find a nice warm spot to set your containers. They do best when kept around 70-80 degrees F. They will not need sunlight until after they germinate. If you don’t have a warm spot, like a water heater closet or the top of an older refrigerator, you can use a grow mat. I will list what I recommend below, if interested.

Most varieties of tomato seeds take 5-7 days to germinate, although some can take up to 14 days.

Be sure to keep the soil moist during this time. Mist the soil twice a day until germination.

After your Tomatoes Germinate

Once your tomatoes have germinated, move them to a sunny window sill. Preferably a South facing window. They will need lots of sunlight.

Your plants love the sun, and will lean towards it, so it is a good idea to rotate them at least once a day, to help keep their stems growing straight and strong.

It’s also helpful to pet your plants. Brushing your hands over them a few times a day strengthens their stems. You can also have a fan set up in the room, for some gentle airflow. But be sure it isn’t close and pointed directly at them, too much wind will damage them at this stage.

Once your tomatoes have their first 2 sets of true leaves (the ones that begin to grow after the initial ones from germination), you can thin your plants if necessary. You want only one plant per container. You will either take a pair of scissors and cut away all but one plant. Or, you can gently remove them all and transplant the others into their own pots.

If you used a seed starting soil that did not contain plant food, you now need to feed your tomatoes. I use a fish emulsion fertilizer. At a ratio of 1 tablespoon to 1 gallon of water. I use this once a week until transplant.

The tomato plants will need to be watered once a day until transplanted into the garden.

When is it Time to Transplant Tomato Seedlings into the Garden

After the date of your last Spring frost, it’s best to wait another week or two (or three) to transplant your tomatoes into the garden, just to be safe.

A week or two before that, you will need to start to “harden off” your plants. This means slowly letting them adjust to the outdoors, a little at a time. I set mine outside in the morning for an hour or so the first day, and lengthen the time by an hour each following day.

Now they’re ready to move to the garden!

Links

Here are a few Amazon links to the seed starting products I recommend:

Seed Starting Pots kit

Biodegradable Seed Starting Pots

Organic Seed Starting Soil (I also like Jiffy’s brand, which is also available here at Amazon)

Fish Emulsion Fertilizer