Black Seeds In Tomatoes – Causes And Dangers


Cutting into a tomato and seeing black seeds can be upsetting. Is the tomato bad? Is it safe to eat?

Black seeds in tomatoes are not uncommon, and they are generally a sign that the tomato is overripe, but there are other causes for the dark color.

To learn more about why tomatoes from the grocery or your garden get black seeds or spots, I put all the information into this quick-read guide.

Tomatoes are a delicious treat any time of year, and knowing the causes of black seeds will help you understand when they are safe to consume, so keep reading!

What Are Black Seeds In Tomatoes?

Black seeds in tomatoes are from the following few factors, but most stem from the abscisic acid levels changing inside the fruit.

Overripe Tomatoes

The older and more ripe the tomato, the more likely you’ll find brown or black seeds inside. This means the seeds are maturing and ready to germinate.

Some tomato seeds actually germinate inside the fruit, known as vivipary, due to the moist conditions.

rotten overripe tomato black seeds inside

Typically by the time the tomato reaches this stage, the exterior of the tomato will be very soft and unappealing to eat.

Harvest Of Green Tomatoes

There also seems to be a higher chance of seeing black seeds in tomatoes that were green when picked.

The reason for the seed discoloration by the time the tomatoes are red and ready to eat may be the sudden drop in acid levels or nutrients once the fruit comes off the vine.

Most green tomatoes take two to four weeks to ripen after harvest, and most tomatoes sent to grocery stores are harvested while green to allow time for shipment.

Blossom End Rot

Blossom end rot is a common disease in tomato crops that can cause seeds to darken.

Blossom end rot happens when the plant cannot take up calcium from the soil quickly enough to keep up with growth and is more prevalent when there’s a lack of regular watering.

blossom end rot tomato on vine

The bottom of the tomato where the blossom was will show signs of blossom end rot by turning dark and mushy. If you cut off the damaged portion of the tomato, you’ll usually see black seeds inside, most likely from the alteration of normal tomato plant nutrient uptake.

Are The Black Seeds Safe To Eat?

While you may find the look of black tomato seeds off-putting, it’s generally safe to ingest them as long as you don’t see any other signs of disease, mold, or pest infestation on the fruit.

Tomato seeds are normally a light yellow or green color, but no matter the shade, the seeds have no taste, so you aren’t going to notice them altering food flavor.

Some people, especially those with food sensitivities, like to remove black seeds in tomatoes by scooping them out before consumption or tossing the whole fruit if it’s heavy with dark-colored seeds.

Other people want their dishes to look nice and will pick out any offending black seeds from the tomato before serving.

The last group of people don’t care about dark seeds in tomatoes and will eat them raw or cooked with no problems.

What Are The Black Spots Inside Tomatoes?

Bacterial canker is the main reason for black spots on the internal flesh of tomatoes.

The canker is a pathogen that also will turn tomato plant leaf edges black and will create a red-brown color on the interior of the stem. On the tomato fruit, the black spots are often surrounded by a creamy-white halo.

The bacteria infection can reach the seeds and also turn them black.

Anthracnose is another cause of black spots inside a tomato.

Anthracnose is a fungal infection of the tomato plant that most affects fruit that grows close to the ground, where it’s easier to pick up the fungi spores. The tomato will form soft spots that will eventually turn black, and the spots may occur outside or inside of the fruit.

Can You Eat Tomatoes With Black Spots?

If the tomato only has one or two black spots and the remaining flesh looks clean and healthy, you can slice away the bad areas and consume the rest safely.

Again, if you have food allergies or a weak stomach, you may want to bypass eating any tomatoes with black spots to avoid possible digestive system upset.

In Summary

Black seeds in tomatoes are nothing to fear and are most often an indication that your tomato is overripe.

I hope this article dispels any fears you have about eating tomatoes with black seeds or spots and explains why dark seeds happen.

Juicy, ripe tomatoes are a great addition to all types of meals, both raw and cooked, so don’t let a few black seeds spoil your enjoyment!

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