Here’s why Tomatoes and Peppers can’t cross-pollinate

Cross-pollination is a funny thing if you save some seeds for the coming years. One time my bell peppers did cross-pollinate with some other type of hot pepper I was growing. On the outside, they looked normal and harmless, but take a bite, and your whole mouth starts to burn. I learned from my mistake and now grow them far enough apart, so it doesn’t happen again. Reading a bit about cross-pollination online, I ran into the question if the same can happen with tomatoes and peppers. I never saw or even heard about a Tomato/Pepper hybrid, so what’s up with that?

Can Tomatoes and Peppers cross-pollinate? No, it’s genetically impossible. Tomatoes and Peppers both a part of the Nightshade family but don’t share the same genus or species. Consequently, they are unable to produce a hybrid through cross-pollination.

To better understand why it is impossible, we first have to take a closer look at how pollination works.


How does Pollination work


A plant needs genetic information from both male and female parts to produce offspring. The male part that provides pollen is called Anther and the female part that receives them Stigma. Pollen is produced in the Anther and transported to other flowers in the area via wind and pollinators. Here’s one of my recent articles about Pollinators if you want to know more. Cross-pollination describes this whole process; it requires at least two flowers -one female and one male.

So what if you only want to grow a single plant? That’s where self-pollination comes into play, as the name suggests the plant produces both the male and female parts, so no other plant is needed. Generally, you can distinguish between plants that produce dedicated male and female flowers (Watermelon) and plants that produce flowers that have both (Eggplant).

Tomatoes and Peppers are both self-pollinating, so is that why they can’t produce a hybrid? Actually, it isn’t; cross-pollination is unlikely in both those plants but not impossible. I already mentioned my hot bell pepper hybrid in the beginning. Similarly, I also had a couple of tomato hybrids.

One important thing to remember, cross-pollination does not affect the fruit you are growing but the next generation. You only really know, if you keep the seeds around for next year, plant them, and taste the new fruit.

So why are there no Peppatoes? Well, let’s look at what makes this hybrid impossible.


Growing Peppers next to Tomatoes

It’s all about genetics. Peppers and Tomatoes belong to the same family: Nightshades. However, they don’t share the same genus; Tomatoes belong to the subgenre Solanum, while Peppers belong to Capsicum. What does that mean?

To put this in perspective, let’s compare this with animals. A well-known family of animals is Canidae (dog-like). Both Grey wolves and red foxes belong to this family, Canis and Vulpes being their genus, respectively. It’s common sense that a hybrid between the two doesn’t exist, so similarly, a hybrid between Peppers and Tomatoes is not possible. I simplified a lot to keep this both short and understandable, animals are more complex than plants, so directly comparing them is a bit of a stretch, but it visualizes the issue quite well. What if I am still not convinced, why should crossing plants from different genomes be impossible?

To illustrate this issue, I’ll simplify it a bit again. The genetic information of both parents is used to create a new unique genome for the child in sexual reproduction. Let’s work with an Analogy and compare this process to a zipper. Both parents unzip their genetic information, exchange their halves of the zipper, and rezip it, creating new unique pairs. Now let’s imagine you have one Zipper that has 950 teeth and another one with 3500. This will work fine for the first 950 pairs, but the leftover 2550 teeth will have no partner and therefore are discarded as useless debris. What’s worse, each tooth actually carries essential information, so they need to line up. In this example, you just end up with 950 pairs of useless information that doesn’t make sense.

The numbers I chose were not random; Tomatoes have about 950Mb of genetic information and Peppers a stunning 3.5Gb; they are simply not compatible. Again I simplified and skipped over a lot of information here; I also want to mention that crosses between different genomes are, in sporadic cases, possible. One of the few examples is Triticale (Triticosecale), a type of wheat that was bred in laboratories; it’s a hybrid of wheat (Triticum) and rye (Secale).

So generally, only plants from the same genus and species tend to cross-pollinate. In rare cases, hybrids from different species form but crosses between different genomes don’t occur naturally.

The good news, you don’t have to worry about growing tomatoes and peppers in the same garden. Sadly this also means the perfect salsa fruit still doesn’t exist.

Are there any plants you shouldn’t plant next to tomatoes/peppers?

Yes, there are a couple of plants that don’t like growing next to them. Similarly, some diseases might become an issue if you grow them close together.

What you shouldn’t plant next to tomatoes and peppers

  • Potatoes: The main challenge of growing multiple Nightshade plants together is the risk associated with blight. This Fungal disease can decimate whole fields in a few days because it spreads rapidly after a single plant gets infected. I dedicated an entire post to blight in tomatoes, so check it out if you want to read more about it. This is also the only reason to maybe avoid planting pepper next to tomatoes.
  • Fennel: This study tested the effect of intercropping different aromatic herbs into a tomato field and noticed a drastic decrease in the production of tomatoes grown with fennel. If you want to grow herbs with your plants, choose basil, it had by far the best outcome and makes a great culinary addition.
  • Cabbage: Growing plants from the Brassica genus together with tomatoes and peppers is quite a controversial topic online. Opinions are all over the place and most of the time without any sources. I tried to find a couple of relevant studies to see if there is an explanation as to why they might not like to grow near each other, and all I could find was this study. It only looked at the pest incidents of cabbage when relay-intercropping tomatoes (shortly before harvest a second plant gets inter-planted in the field of the first crop). In conclusion, they noted that lower yield might be due to the competition for nutrients and light.
  • Beans: Growing legumes and tomatoes together might be quite a challenge, as they have very different needs. However, if you can manage to make both plants happy, then there shouldn’t be much to worry about. Make sure to keep an eye on your plants though; beans tend to strangle other plants around them. For that reason, I prefer to grow them separately.


How to prevent cross-pollination

Source – by CC 3.0

Let’s say you have a fantastic tomato plant and want to negate any chance of cross-pollination: what do you do?

Pollination bags

These fabric bags are used to cover the flowers of your plant so that no pollen can reach it. This is an easy and safe way to prevent cross-pollination, but you need to invest some money upfront. (Here’s a link to Amazon to check current pricing. I earn a small commission if you use this link and buy something, this is a great way to support me if you like my content)

Growing distance

Jeff McCormack from Southern Exposure Seed Exchange did a fabulous job to provide some numbers in this article.

Modern tomato varieties need about 10ft (3m) and older ones 20ft (6m) to ensure purity. It’s also a good idea to separate different tomatoes species by planting a “blockade” crop. This will reduce the number of bees getting to your tomato flowers and also block some wind, further decreasing the chance of cross-pollination. So any plants that produce lots of pollen (i.e. Squash) or grow quite tall (i.e. pole beans) make a great barrier.


What about the pictures/videos you can see online


But wait, what about the pictures you can see online that look like a cross between pepper and tomato?

The answer is already in the question; they only look like it. One example is the stuffer tomato, they are predominantly used to make stuffed tomatoes (who would have thought), so they are hollow on the inside. This tomato seriously looks like a mix of tomato and bell pepper. Other heirloom tomatoes might also have some resemblance to peppers, making it all the more confusing.

But as I said earlier, there can’t be a natural cross between pepper and tomato, so they just look like a hybrid without being one. Some of them are actually marketed as a hybrid; this is just misleading. Maybe one day, some genetic engineers decide to create the perfect salsa Peppatoes, but until this day, they don’t exist.


Related Questions

Is cross-pollination bad? No, it isn’t. Granted, you’ll end up with lots of hybrids you never want to grow again. But in some odd cases, you stumble across something amazing, literally creating your own variety. Cross-pollinating plants is a great way to personalize the plants you grow and gives room to do your own experiments. Just make sure to do some research before you start to cross-pollinate your plants deliberately. In some cases, it can lead to backcrossing and reintroduce dangerous traits, like cucurbitacins in zucchini. If it tastes unusually bitter, stay away from it!

How often do Tomatoes or Peppers cross-pollinate? Well, there are no exact numbers, and it depends on a lot of factors, so it’s hard to say for sure. However, it is pretty unlikely (I did come across a chance of 1-3%). From my own experience, I only had one pepper hybrid and two or three tomato ones in the past couple of years.