How Many Tomato Seeds Per Hole + Tomato Seed Germination Tips

Planting tomato seeds can be tricky if you need to know how many seeds to plant per hole. Our tomato seedling guide will provide all the necessary information about planting tomato seeds, including how many seeds to plant per hole, the right temperature for planting, and how to ensure the seeds germinate successfully.

Preparing to sow a handful of tomato seeds.

Sound good?

Then, follow these tips for healthy tomato growth and delicious fruit!

Number Of Tomato Seeds Per Hole

Planting tomato seeds in tiny peat growing cups.

We grow tomato plants every year from seed. From experience, we can tell you that planting two to three fresh tomato seeds per hole works best to ensure that at least one healthy seed germinates per hole.

Consider adding three or four seeds per hole if you have older tomato seeds. The freshness of the tomato seeds heavily impacts their germination rate, and if the seeds are over a few years old, two or three seeds might not be enough to produce a plant!

In other words, older tomato seeds have inferior germination rates compared to fresh tomato seeds. Thus, we must compensate by growing a few extra tomato seeds per hole if they are old.

So, we’ve found two to three seeds per hole to be the sweet spot for new seeds. If the seeds are older, we say three to four seeds per hole. (If your tomato seeds are over six or seven years old, they might not germinate! But they’re still worth a shot.)

Dealing with old tomato seeds is a balancing act. They usually have dismal germination rates, but they might surprise you. The good news is that even if you accidentally plant too many tomato seeds per hole, you can always thin the sprouting plants later. When they’re ready for the big leagues, transplant them safely in your garden, with around two feet between plants. You can’t lose.

Factors To Consider When Planting Tomato Seeds

Sowing tomato seeds into a seed tray with seed starter mix.

Tomato seeds are slightly trickier to germinate and nurse indoors than cucumbers or sunflowers. From seed germination rate to soil moisture and temperature, every aspect plays a crucial role in determining the success of your tomato plants.

Consider the following factors.

Tomato Cultivar

There are many varieties of tomatoes to choose from. Determinate tomatoes grow to a predetermined height, and then they stop, making them an excellent option for container gardening or short-season growing. Indeterminate tomatoes, on the other hand, grow taller and continuously produce fruit throughout the season.

For those interested in heirloom tomatoes, there are many options for nearly every growing zone in the USA. Heirloom tomatoes are famous for their unique flavor and appearance. Some popular varieties include Brandywine, Cherokee Purple, and Green Zebra.

Tomatoes come in myriad shapes, colors, sizes, and flavors. Despite these differences, most tomato seeds look virtually identical and germinate the same! However, the tomato plant’s variety and mature size impact how and where you grow your plant.

Best Soil For Tomato Seed Germination

Tomato seeds require warm, room-temperature soil to germinate. A good rule of thumb is to aim for a soil temperature of around 70 to 75 degrees Fahrenheit. Heat mats help maintain a consistent temperature, especially if your home is chilly.

It’s also essential to ensure the soil is moist but well-drained and nutrient-rich, with a pH between 6.0 and 6.8. Tomatoes prefer well-draining soil, which helps prevent waterlogging, which can introduce rot, mold, or other plant diseases.

Size And Type Of Container

Young tomato seedlings growing in biodegradable cups.

Tiny peat pots are the best for germinating tomato seeds indoors. We’ve had excellent luck with individual grow cups and trays. (The trays are best for using a heat map.)

After a few weeks, it’s time to transplant your tomato plant into something more significant. We’ve had excellent luck growing tomatoes outdoors in 20-gallon grow bags. They’re big enough to never topple over in the wind and small enough that you can move them around your yard if you need to. (Well, as long as you have a helping hand!)

You can also grow tomatoes in a much smaller pot, like a five or ten-gallon terracotta pot. If you notice your tomato plant roots sticking out the bottom of the pot, replant them into something more spacious.

Reusable containers made from recyclable or reusable materials, like yogurt containers or egg cartons, also work perfectly for starting tomatoes. They are small and allow for easy transplanting when starting seeds.

(No matter which pot you use, ensure it has proper drainage. Or, your tomato plant roots will invariably suffer.)

Location For Growing Tomato Plants

Bright red beef tomatoes growing in the backyard garden.

Once your baby tomato plants emerge, sunlight becomes a significant issue. Tomatoes need boatloads of direct sunlight, ideally six to eight hours daily, to grow and produce fruit. Choosing an area in your garden or yard that receives ample sunshine throughout the day is paramount.

In addition to sun exposure, moisture levels are critical for growing healthy tomato plants, even after you transplant them in your garden. Too wet or dry soil can inhibit plants’ growth, and inconsistent water might lead to issues such as blossom end rot. Raised beds are excellent for helping ensure consistent moisture levels, as they allow for good drainage while keeping the soil moist.

I’ve seen farmers and gardeners argue about how much water tomato plants need! Most agree that two inches of weekly water works best. But consistency is the key. I’ve seen more than one magnificent tomato crop destroyed due to blossom end rot! Blossom end rot occurs with inconsistent watering. So, ensure your tomato soil stays consistently moist! Stick your finger in the soil once every few days. And if it ever feels dry, give it a drink.

Temperature

Temperature is another essential factor when choosing a location for growing tomatoes. Tomatoes prefer warm temperatures, around 70 to 80 degrees Fahrenheit during daytime and 60 to 70 degrees during night. If you live in a cooler climate, a greenhouse or a container placed on a sunny windowsill can help create the optimal growing conditions for your tomato plants.

Germinating The Tomato Seeds

Beautiful tomato seedling emerging from the soil.

Germinating tomato seeds can be a fun and rewarding experience for any gardener. The process is captivating, from deciding the variety of tomatoes to watching the first sprout emerge from the soil.

We also remind you that tomatoes are one of the trickiest crops for germinating successfully indoors, and they get ludicrously lanky if they lack adequate sunlight. However, we have extensive experience that can help you.

Here are our best tips.

Preparing The Soil Mixture And Planting The Seeds

Preparing rich potting soil for germinating seeds.

Choose a seed starting mix suitable for tomatoes. Nearly any decent seed starting mix will work fine. Fill the container with the seed starting mixture until it is approximately one inch below the top rim.

Next, create small holes roughly one-quarter to one-eighth-inch deep for the tomato seeds to go into. Depending on the germination rate of the chosen seed variety, try to place two or three seeds per hole. Consider putting extra seeds per hole if the seeds are older or if you want guaranteed germination.

Once the seeds are in place, cover them with soil and gently pat it down to ensure good seed-to-soil contact. Keep the soil moist for best results, and place the growing pot in a sunny or well-lit location. If you don’t have sufficient natural light, consider using grow lights or a heat mat to maintain warm room temperatures for optimal seed germination.

Waiting For Germination

Tomato seedlings growing on a sunny windowsill.

Your tomato seeds should begin germinating after five to ten days. You’ll notice tiny green plants emerging from the soil. When the tomato seedlings germinate, it’s time to move them to a bright, sunny spot. (A sunny windowsill works perfectly.)

After a few weeks, they will develop their first leaves. And then, it is time to move them into a larger pot. If more seeds germinate than you expected, select the healthiest ones to keep and remove the excess plants.

Look for sturdy stem seedlings, healthy green leaves, and a robust root system. These seedlings are more likely to grow into healthy and productive tomato plants. Remove the weaker seedlings to provide more space and resources for the stronger ones.

If you end up with more seedlings than you can plant, consider giving them away to friends or neighbors or donate them to your local garden center. Alternatively, transplant them to larger containers and grow them as indoor plants. (Too many tomatoes are always a good thing.)

Frequently Asked Questions

Planting tomato seeds can raise concerns regarding seed quantity, spacing, and compatibility with different plants. To provide clarity, here are some frequently asked questions and their answers.

How Many Tomato Seeds Should I Plant?

Two to three seeds per hole are usually your best bet. However, also consider the cultivar and instructions on the packet. Seed packets often include instructions on the recommended number of seeds per hole or cell. The number can vary depending on the tomato variety, expected germination rate, and container size.

Should I Plant Multiple Tomato Seeds Per Hole?

Yes! Planting more than one seed per hole can help compensate for low germination rates and ensure a total amount of healthy plants. However, space the seeds evenly as they emerge to prevent overcrowding and resource competition.

Can I Plant Tomatoes Next To Other Plants?

Tomatoes can be compatible with some plants like basil but can also negatively affect others due to their allelopathic properties. Avoid planting them near fennel, Brassicas, or other nightshades.

What Is The Ideal Spacing For Tomato Seeds?

Plant tomato seeds about one-eighth to one-quarter-inch inch deep, with holes two to three feet apart. If you germinate seeds indoors, wait for them to form true leaves. Once the seedlings have their true leaves, transplant them into individual containers or a larger space.

Do Tomato Seeds Have Inferior Germination Rates Compared To Cucumbers Or Squash?

Yes, we think so. We’ve done the tomato seed germination math! Our fresh tomato seeds germinate only around 85% of the time. Older seeds are much worse than that, with perhaps a 50% germination rate for five or six-year-old seeds. (Our fresh cucumber, squash, and sunflower seeds germinate around 95% of the time! So, tomato seeds are slightly trickier to germinate compared to cucumbers, in our experience.)

Conclusion

Thanks for reading our guide about sowing and germinating tomato seeds. We grow tomatoes yearly. We posit that sowing two to three tomato seeds per hole is best.

What about you?

Are you growing tomatoes this year? Which cultivar?
How many tomato plants are you growing?
How many seeds per hole do you usually grow?
Do you sow tomato seeds outdoors? Or do you start them indoors?
Is buying baby tomato seedlings at a local plant nursery better?

We love brainstorming with like-minded tomato growers.

And we hope to hear from you!

Thanks again for reading.

Have a great day!

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How Many Tomato Seeds Per Hole + Tomato Seed Germination Tips

Number Of Tomato Seeds Per Hole