Should I Let Self-Seeded Tomatoes Grow? | Pros and Cons

Self-seeded tomatoes can pop up anywhere that an old tomato has been left on the soil. The seeds will sprout when soil temperatures are warm and when the soil is moist. The positives of letting self-seeded tomatoes grow are that they are free, they grow fast and their roots will not need to be be disturbed when transplanting.

The cons include that you won’t know what type of fruit you will get until the plant matures.

This article will explore the answer to whether you should let self-seeded tomatoes grow, the pros, cons and what you can do instead.

What to consider when growing self-seeded tomatoes

Here are a few things to think about before you let your self-seeded tomatoes grow too large.

What was the mother plant?

Think about the types of tomato plants you were growing in the patch. That way you can get some idea about what the plant might turn into. If the plant is an heirloom variety it will set viable seed and will grow fruit. If the seed comes from a hybrid then the seed may not grow or it may not grow fruit.

Each flower will have been pollinated and potentially cross pollinated by a different tomato variety. This could lead to some interesting results but not the exact same tomato variety that you had planted previously.

Are they growing in the right spot?

These tomato seedlings are growing near a paver in my pathway.

Tomato seedlings can pop up everywhere, in between pavers, on the edge of the garden bed, in nearby pots or on paths. If tomato seedlings pop up in the right spot this will save you the trouble of transplanting and will prevent any root damage.

IF they are not growing in the right spot, they can be pricked out when they have developed their second set of leaves. Use a popsicle stick to lift them out and transfer them to a small pot with good quality potting soil.

Will they shade other plants or take over?

Tomato seedlings can eventually shade nearby plants if they grow fast enough.

Tomato seedlings can take over quickly and if you are growing other seeds in your patch then they could be shaded or smothered by the tomato. While tomatoes can happily share the space with peas, beans, strawberries and larger seedlings like peppers, they can quickly shade out carrots, lettuce and Asian greens.

Top reasons to grow self-seeded tomatoes

Here are the top reasons why you would keep self-seeded tomatoes that have popped up at home.

1. To experiment

The top reason to keep self-seeded tomatoes is to experiment with new varieties. Self-seeded tomatoes will often be cross pollinated and can create your own variety of tomato at home. It is fun to see what kind of free tomato is popping up in your yard.

I even had tomatoes grow in areas of my garden that had never had vegetables. There may have been tomato seeds in compost I added or the previous owners of the home may have planted them there. You can prick the seedlings out when they are small and move them without worrying about if you lose one or two because they grew for free.

2. If they grew from an heirloom seed

If you are growing heirloom tomatoes at home then they will produce viable seed and tomatoes that will produce fruit. These tomatoes grow from the seed of our original tomato varieties without any modification.

They are great if you like to collect seed or want to just wait it out and see what pops up. Heirloom tomatoes can be grown year to year from seed collected or self-sown from the mother plant.

3. As a green ground cover

Tomato seedlings can actually work to fill a garden bed at the end of the summer season. I get lots of tomato seedlings pop up in fall which can be dug into the soil as a green manure. Most of these tomatoes seeds pop up from cherry tomato plants that I had growing in the same bed.

They will add extra nutrients including nitrogen to the soil ready for my next crop. I will cover the lot with bark mulch to prevent weeds from coming up and to keep the soil moist.

This bed will be used for beans, peas and strawberries over winter so I will remove all of the tomato seedlings

Growing self-seeded tomatoes – Pros

Here are the top benefits of growing self-seeded tomatoes at home. Think about these before you pull out all of those baby tomatoes that have popped up in your yard.

  • Free
  • Easy to grow
  • You won’t disturb the roots
  • Early crops if the seeds are left to set in early spring or late winter
  • You could get a new tomato variety or different colors than last year
  • Use them as a green manure to benefit the soil

Growing Self-seeded tomatoes – Cons

Here are the cons to consider when growing self-seeded tomatoes at home.

1. Possible diseases and pests

Growing tomatoes in the same space as last years crop can spread disease or pests from plant to plant. Nematodes that exist in the soil that affected the plants in the previous season can live on and affect the new plants if they are grown in the same space.

2. You don’t know what you will get

While this might be considered a pro, not knowing what type of tomato you will get can be a problem. If you want cherry tomatoes and end up growing saucing tomatoes or vise-versa means that you might not end up with what you wanted.

If you have garden space to spare than you can let the tomatoes grow and plant some specific varieties in another area.

3. Tomato seedlings can overtake other seeds and crops

Tomato seedlings grow large quickly and cast shade which can affect the other seeds and seedlings you are growing in the same patch. They can shade nearby seeds slowing their growth or disturb them as they grow.

Tomato seedlings can share the space with other large seed crops like peas and beans but can stop your carrot and lettuce seeds from growing well.

4. Fungal growth

These seedlings have some fungal growth because they are growing near the ground in the cooler weather.

Tomato seedlings can appear in the cooler parts of the year like the end of fall. Growing seedlings in the cooler part of the year can lead to fungal growth on leaves, which could spread to other plants. Ideally seeds should be sown in early spring or even late winter if you have a greenhouse.

Tomatoes grown outside of the warmer season may not survive the winter frosts and will not grow fruit.

What to do instead of growing self-seeded tomatoes

The best thing to do to reproduce your tomato plants is to collect seeds at the end of the season. Choose your best, heirloom plants and squash the seeds into a jar of water. Let the seeds soak for 24 hours and then pour them out onto paper towel.

Allow the paper towel to dry and then store the paper towel in a jar until spring. You can cut the paper towel into pieces and place it in potting soil or your garden bed to sprout. Seeds preserved in this way can last for 2 years or more in storage.

Check out my quick video guide to save seeds even faster. This method will keep the seeds viable for 1-2 years.

Should I let self-seeded tomatoes grow? | Summary

Self-seeded tomatoes are a great, easy way to get tomatoes for free year to year. If you are growing heirloom tomatoes they will grow into a fruit producing plant. If you are growing hybrid tomatoes, then it is best to buy fresh seedlings each year and rotate them around to a new garden space each season.

Happy growing.