Can You Plant Tomato Seeds Directly In The Ground?


Maybe you are impatient to start growing your tomatoes, or maybe you waited too long to start tomato seeds indoors.  Maybe you are just wondering if it is really necessary to start tomato seeds indoors, and if so, why.

So, can you plant tomato seeds directly in the ground?  Yes, you can plant tomato seeds directly in the ground if you live in a warm climate with a long growing season.  For colder climates, you should start tomato seeds indoors and transplant the seedlings outdoors later.

Of course, there are plenty of good reasons to start tomato seeds indoors, even if you live in a warm climate.  Remember that by planting tomato seeds directly in the ground, you might make things more difficult for yourself and for your tomato plants.  Let’s take a closer look at why that is, and what you should do instead.

Can You Plant Tomato Seeds Directly In the Ground?

Yes, you can plant your tomato seeds directly in the ground outside (known as direct sowing), as long as your climate is warm enough and the growing season is long enough (74 to 123 days – more on this later!).  If you are going to plant tomato seeds directly in the ground, there are a few things to keep in mind.

First, remember that tomatoes are a warm-weather crop.  They are not suitable for planting before the last frost date in an area (unlike cool-weather crops, such as peas and onions).   Thus, you will need to plant tomato seeds much later in the season than other crops.

Also, remember that a tomato seed started directly in the ground will mature and produce fruit later in the season than a transplant started indoors.  When you start seeds directly in the ground, they do not get a “head start” on the growing season by starting indoors before the last frost date.

tomato plants
Tomato plants that start too late in the season may not produce ripe fruit before the last frost date.

This can be a big problem in cold climates with a short growing season.  In a cold climate, the tomatoes might not be ready to harvest before the first fall frost!

Finally, remember that both cold and hot temperatures can be a problem for tomato plants.  Tomato seeds will only germinate in soil that has a temperature of 50 to 95 degrees Fahrenheit (10 to 35 degrees Celsius).  An ideal soil temperature range for tomato seed germination is 65 to 85 degrees Fahrenheit (18.3 to 44.2 degrees Celsius).

Note: tomato seeds take 6 to 11 days to germinate under the proper conditions (soil temperature, moisture, etc.).  You can learn more about optimal conditions for tomato seed germination here.

What Happens If You Plant Tomatoes Too Early?

If you plant tomatoes too early, then there is a higher risk that the plants will be killed by a frost (temperatures below 36 degrees Fahrenheit or 2.2 degrees Celsius) or a freeze (temperatures below 32 degrees Fahrenheit or 0 degrees Celsius).

If you plant tomato seeds too early, then the soil will be too cold, and the seeds will not germinate.  This will lead to a delay in the development of your plants.  Starting the tomato seeds indoors will help you to avoid this problem.

Of course, you can always use a cloche to keep your tomato seeds and seedlings a little warmer.  A cloche is a covering that protects a plant from cold, wind, and insects, while allowing sunlight through.

water bottles
You can make a cloche by cutting the bottom out of a plastic bottle.

This sunlight helps to heat up the air inside the cloche and the soil underneath it.  The greenhouse effect prevents heat from escaping and keeps the tomato plant warmer.

Usually, a cloche is made of plastic.  You can make a cloche out of an ordinary plastic water bottle with the bottom cut out.

You can even take off the cap on the bottle, so that the opening can act as a vent.  This will give the plant some air on hot days and prevent overheating.

What Happens If You Plant Tomatoes Too Late?

If you plant tomato seeds too late, then the summer heat will prevent the seeds from germinating.  Even if the seeds do germinate, the plants may not mature fast enough to produce ripe fruit before the first frost in the fall.

A frost or freeze will kill tomato plants, so they need to finish growing and producing fruit before the first frost.  Most tomatoes take anywhere from 74 to 123 days to grow from a seed to a mature plant that produces ripe fruit.

If you start tomato seeds indoors and transplant them outside later in the season, then the plant will only need 7 to 14 weeks (49 to 98 days) to produce ripe fruit.

Steps to Take if You Direct Sow Tomato Seeds

If you do decide to direct sow your tomato seeds, there are a few important steps that you need to take.

First, prepare the soil for planting:

  • Choose the right area for planting.  Make sure that the spot you select has well-draining soil and gets plenty of sunlight.  Early in the season, you will have to think ahead to avoid a spot that is shaded by the leaves of trees later in the season.
  • Add some compost to your soil.  This will improve the soil structure and allow the soil to retain some water without staying too wet.  Compost will also provide nutrients for plants.  In addition, compost will provide organic material for beneficial soil organisms (bacteria and earthworms).
  • Add fertilizer, if necessary.  Get a soil test before adding anything to your soil, to find out if it is really needed.  Always follow the instructions on the package, since it is possible to over fertilize your plants!
  • Sift your soil.  This will remove any rocks, sticks, roots, or other debris that can prevent seeds from growing properly.
  • Wait for warm weather.  The soil temperature should consistently be over 50 degrees Fahrenheit (10 degrees Celsius) for tomato seeds to have any chance of germinating.  This will certainly be after the last frost date in your area.  The Old Farmer’s Almanac has a tool here, which you can use to look up frost dates.
compost bin
Compost will add nutrients and organic material to your soil, and you can make it from yard and kitchen waste.

Next, plant your seeds:

  • Plant each tomato seed at a depth of 0.25 inches (0.6 centimeters).  Plant the seeds in a row, about 2 feet (0.6 meters) apart.
  • You may want to install supports now, before the plants grow, to avoid damaging their roots.  For taller indeterminate tomato varieties, use stakes driven into the ground close to the seeds.  For shorter determinate tomato varieties, use tomato cages with the planted seed in the center of the cage.
  • If planting multiple rows of tomatoes, leave 4 feet (1.2 meters) between rows.  This will allow enough space later in the season for pulling weeds and watering, fertilizing, inspecting, and harvesting.

Finally, take care of your plants as they grow:

  • Water your seeds carefully.  Too much water will wash away soil and seeds alike.  It might be easier to keep the soil moist by using a spray bottle.  After the seeds germinate and seedlings emerge, you can use a watering can or hose to provide more water.
  • For indeterminate tomato varieties, use twine to tie your tomatoes to the stake as they grow.  This support will keep them from falling over or breaking due to the weight of the fruit.  Keeping the plants off the ground will also decrease the chances of diseases (which are found in the soil).

Why Should I Start Tomato Seeds Indoors?

When you start tomato seeds indoors, there are several advantages over direct sowing.

You Can Thin Your Seedlings (Plant the Strongest)

One advantage of direct sowing is that you can plant many more seeds than you need.  Then, you can plant only the strongest seedlings that emerge.

This process is known as thinning your seedlings.  Thinning your seedlings ensures that plants do not compete with one another, and also ensures that you have extra plants to avoid falling short.

If you were to simply plant seeds outdoors, some of them would fail to germinate and grow.  By then, it might be too late in the season to replace them with new tomato seeds.

You Can Extend the Growing Season

When you start tomato seeds indoors, you can extend the growing season.  This is especially useful in cold areas with short growing seasons.

The Old Farmer’s Almanac recommends starting tomato seeds indoors 6 weeks before the last spring frost date, and transplanting seedlings outdoors 2 weeks after the last spring frost date.

By using grow lights, heat mats, and humidity domes, you can start tomato seedlings indoors.  By the time you transplant them outside, they will be well-established.

Tomato seedlings should be transplanted to larger pots when they have their first set of true leaves, at a height of 2 to 4 inches (5 to 10 centimeters) tall.  They can be transplanted outdoors 8 weeks after planting from seed, at a height of 6 to 10 inches (15 to 25 centimeters) tall.

tomato seedling
Tomato seedlings germinate in 6 to 11 days. Transplant them to bigger containers at 2 to 4 inches tall, and transplant outside 8 weeks after planting the seeds.

Just remember that you will need to harden off your tomato seedlings when transplanting them outdoors.  To harden off your seedlings, expose them to outside conditions gradually over time.

Start off by giving your seedlings a little exposure to the sun, wind, and weather outside.  Over time, slowly give them more exposure to the sun and to the elements so that they can adapt to these conditions.

Eventually, you can move the seedlings into full sunlight and let them fend for themselves (although you still need to water them as they grow!)

Conclusion

It is possible to plant tomato seeds directly in the ground (direct sow) and end up with healthy plants.  However, this is more likely to be successful in a warm climate with a long growing season.

I would recommend starting tomato seeds indoors and transplanting them out to the garden later.  This helps you to avoid late spring frosts, and it extends the growing season.  It also ensures that you will have enough healthy transplants to grow as many tomato plants as you want.

I hope you found this article helpful – if so, please share it with someone who will find the information useful.  It’s time to get started with planting your tomato seeds!

jonathon.david.madore

Hi, I'm Jonathon. I’m the gardening guy (not guru!) who is encouraging everyone to spend more time in the garden. I try to help solve common gardening problems so that you can get the best harvest every year!

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