Hybrid vs. GMO vs. Heirloom

Bowl of Heirloom and Hybrid Tomatoes

The difference between heirloom and hybrid tomatoes isn’t necessarily visible on the outside. It’s about the breeding. (image source: iStock.com)

There is a lot of confusion out there regarding hybrid vs. GMO vs. heirloom plants, especially when it comes to tomatoes. What’s the difference? This simple guide sorts it out for you. (Bonnie Plants offers both hybrid and heirloom varieties, but every plant we sell is non-GMO.)

Sweet, delicious Sun Gold tomatoes prove that hybrids can have a ton of flavor.

Sweet, delicious Sun Gold tomatoes prove that hybrids can have a ton of flavor.

Hybrid Plants

A hybrid vegetable is created when plant breeders intentionally cross-pollinate two different varieties of a plant, aiming to produce an offspring, or hybrid, that contains the best traits of each of the parents. Cross-pollination is a natural process that occurs within members of the same plant species.

In hybridization, pollination is carefully controlled to ensure that the right plants are crossed to achieve the desired combination of characteristics, such as bigger size or better disease resistance. The process of developing a hybrid typically requires many years.

One example is Juliet, a 1999 All-America Selections winner. This Roma-style grape tomato offers great taste and productivity along with improved disease resistance to increase success in the garden. Another is Sun Gold, a prolific yellow cherry tomato that’s so sweet and delicious, it’s like candy from the garden.

In general, hybrids offer some combination of these favorable traits: dependability, less required care, early maturity, better yield, improved flavor, specific plant size, and/or disease resistance. Hybrid vegetables typically look like the veggies you’d find at a supermarket.

GMO Plants

GMO plants, on the other hand, are the result of genetic engineering. (“GMO” stands for “genetically modified organism.”) This is a process during which the plant’s DNA is altered in a way that cannot occur naturally, and sometimes includes the insertion of genes from other species. All of our plants are grown from non-GMO seeds.

grandfather picking tomato

Many older people have grown the same heirloom tomatoes for many decades.

Heirloom Plants

How experts define heirlooms can vary, but typically they are at least 50 years old, and are often pre-WWII varieties. Most heirlooms come from seed that has been handed down for generations in a particular region or area, hand-selected by gardeners for a special trait. Others may have been developed by a university a long time ago (again, at least 50 years), in the early days of commercial breeding. All heirloom vegetables are open-pollinated, which means they’re pollinated by insects or wind without human intervention. In addition, they tend to remain stable in their characteristics from one year to the next.

Many gardeners agree that most heirloom varieties boast greater flavor than that found in hybrids, especially among tomatoes. Bonnie’s heirloom tomato varieties are clearly marked on the plant trays.

While hybrid plants typically yield a crop that is uniform in both appearance and timing, heirloom vegetables may produce a “mixed bag” harvest. The harvest may come in less predictably, and fruit size can vary greatly even on the same plant.

Despite their sometimes odd looks and quirky ways, heirlooms bring lots to the table (literally!). The Amish heirloom tomato Pink Brandywine, for example, yields fruit with an unbeatable flavor in shades reminiscent of a glass of Cabernet. Arkansas Traveler, a Southern favorite, originated in Northwest Arkansas prior to 1900 and gradually found its way across the South to North Carolina. Resistant to cracking and disease, this beauty yields delicious tomatoes under typical Southern summer conditions–high heat, high humidity, and drought.

What Kind Is Right for Me?

In the battle of hybrid vs. GMO vs. heirloom plants, we suggest growing both hybrid and heirloom vegetables (especially tomatoes!). Doing so will ensure a reliable, flavorful harvest that offers a lot of variety and, truly, the best of both worlds.


CL Atkins

I have about 3 different variety of tomato plants that are all planted in the same vacinity of each other. I had not thought about pollination.

Will they be ok together as far as producing what they are supposed to or should they have been planted in seperate areas?

Danielle Carroll

Hello CL,
They are fine where they are planted! – danielle, Bonnie Plants

Danielle Carroll

Hi Patricia,
All Bonnie Plants either heirlooms or tradional hybrids grown from non-GMO seed. You can read more about Bonnie Plants green practices here. – Danielle, Bonnie Plants

Joe McBride

Circumstances pretty much limits my gardening to self-watering containers, and I get very good results growing tomatoes. One of the things I really like to do is try a few different varieties each year. When I look at the Bonnie web site, I see many unique tomato varieties that I would love to try, but the retailers in my area seem to all carry the same few varieties. How can I go about finding a source of some of your more unique plants in my area?

Mary Beth

Hi Joe,
Thanks for your comment. It’s great to hear that you are enjoying good results with your Bonnie tomatoes. Self-watering containers are very smart and leave you hands-free to enjoy your garden and its harvest more. Our tomato varieties vary by region, as each geographic area is provided with what will grow best in that climate. For instance, Seattle’s Best or San Francisco Fog and Early Girl are perfect for northwest gardeners with short summer seasons. Our heat tolerant tomatoes are wonderful for sunny Florida and most of the Southeast and Southwest in the summer’s heat. If you are looking for a specific variety, you can ask your local gardener center to have the Bonnie rep add it to his next delivery for you, if available. If you want to know if a specific one is available in your area, you can email our Customer Service, too. Happy gardening! ~Mary Beth, Bonnie Plants


Are any of your hybrid tomatoes that I buy at Home Depot nemitode resistant or not effected by nemitodes. I get my plants going great ready to fruit and all of a sudden they begin to die back. Roots signal nemitodes. I just purchased Big Boy a hybrid but can not find out if they will be resistant to nemitodes.


Hello! I buy your veggie plants every season and am VERY happy that they are not GMO!!! This might be a stupid question but can you grow producing tomatoes from hybrid tomato seeds? I have heard different on both sides! Also, I live in Galveston, Texas and was wondering where I can buy your heirloom veggie plants?

Mary Beth

Hi Leah,
Thanks for your kind comments! You’re right; we’re no-GMO. Hybrids are desirable for traits they’ve inherited from both parents, but they will not produce seed that is exactly like this plant the next year. They will produce fruit, but there’s no telling what characteristics your plant will have. You can find locations that sell our plants using this ZIP code tool: find.bonnieplants.com. If you want help de-mystifying more garden terms, check out our Garden Glossary. ~Mary Beth, Bonnie Plants

Lauren Stephens

These *hybrids* are actually GMOs, that is, Genetically Modified. What a bad idea to promote that stuff.

Mary Beth

Hi Lauren,
Actually, hybrids are not at all like GMOs. Hybrids are naturally occurring and nothing sinister. Two zinnia flowers can cross-pollinate naturally in your flowerbed, create a seed, and produce a new type of bloom the following season. In the simplest explanation, that is a hybrid. If you cross-pollinate a cherry tomato that has a flavor you love with a grape tomato that is a robust grower, you try to get the best traits of both in the next generation plant. However, GMO “can be any plant, animal or microorganism which have been genetically altered using molecular genetics techniques such as gene cloning and protein engineering.” There’s much to be learned about this frequently misunderstood topic. The traditional hybrids that all of us home gardeners grow are not GMO. Bonnie Plants are no-GMO. I hope this helps! ~Mary Beth, Bonnie Plants

Irene Giordano

Hi Kelly,
My daughter and I planted 1 heirloom tomato plant in your organic pot a lil late in season. We dug up a huge area and used nothing but Miracle Gro Garden Soil and transplant starter food..THE PLANT EXPLODED!..we’ve counted over 14 tomatoes so far but they are not ripening. 1 weighed over 8 oz., was hard as a rock, and deep green…4 other tomatoes were on the same branch, still growing, but the weight of all them broke the branch!..the plant is in full sun, day temps are in the 80’s w/low humidity, nights go down to 60’s @coldest and we water every day unless it rains hard…PLEASE tell us what we r doing wrong that they won’t ripen even though we wait once the tomato becomes a good size

Kelly Smith Trimble

Hi Irene,

Sometimes I think that patience is the hardest part of gardening! The tomatoes should ripen if you give them time. Some fruit takes longer to ripen than others. Be sure to support your tomato plants well so those branches don’t break under the weight. I keep a roll of twine with me whenever I go out into the garden, because I know some tomato or pepper branch will need to be tied up more. Also keep plants consistently watered and give them a boost with liquid vegetable fertilizer (such as our Bonnie Plant Food) too. I hope this helps!

Kelly, Bonnie Plants

Janice Sanders

I have gardened my entire life, and have a problem that I had not encountered previously. I buy Bonnie plants almost exclusively and have been very pleased. I am growing 8 different varieties this year, and a long-time favorite is Mr. Stripey. I bought a plant labeled Mr. Stripey (looked identical to all others with that label), but it bears nice large, solid yellow tomatoes. I am so disappointed! I love sharing my harvest, and have introduced a number of friends to this yummy, strange-looking tomato. Can this type thing happen with an heirloom plant, or did someone pull a switcheroo with the tags?
I want to be sure to find the correct plant next year. Thank you!

Kelly Smith Trimble

Hi Janice,

Yes, Mr. Stripey is a great heirloom tomato! As you know, the fruit from this plant varies, which is part of its charm, so it could produce a solid yellow fruit. The fruit might have some variation inside, such as spots of red. It could be that the tags were switched at the store and you have a different tomato, but I bet this Mr. Stripey is just giving you something a little different. Happy growing!

Kelly, Bonnie Plants


Hi, Kelly,

I planted a hybrid tomato plant in a big pot on 5/19 and it grows upto 28 inches tall now with many fruits. The first fruit is as big as our palm for two weeks but still green with black ring around the top underneath the stem. Is it normal and how can I trim the plant to enrich the furits? Your reply is appreciated.

Kelly Smith Trimble

Hi Angel,

It sounds like your plant is growing well so far! Pruning shouldn’t be necessary for the plant to produce good fruit. The problem you’re describing on your fruit could be blossom end rot, which is a common problem caused by a calcium deficiency. Read our article on blossom end rot to decide if that’s what you’re seeing and learn how to fix it. I hope this helps!

Kelly, Bonnie Plants


I need to know if your tomato plants can get a sunbrun and some told me to put esponsalt on them is that good for them because they are makeing tomatos .

Kelly Smith Trimble

Hi Lisa,

Yes, according to this article from Oregon State University Extension, green tomatoes can get sun scald. You should remove damaged tissue and discard burned fruit. Some gardeners do use Epsom salt in their garden as a fertilizer, putting a few tablespoons in the hole before planting tomatoes and peppers. Epsom salt contains magnesium, which can help create strong cell walls. There’s no scientific evidence that it works, but some gardeners swear by it. Happy growing!

Kelly, Bonnie Plants

Mary F ONeal

We purchased a heirloom striped tomato plant a month or so ago. It has really grown tall and has lots of blooms, but, they seem to just dry up. What is going on????

Ed Umbaugh

A seed from an open pollinated plant could be a hybrid if it the parent plants are both line bred plants that cross pollinated by chance. To prevent this in the production of hierloom seed isolation from other varieties is required. Most hybred seeds are F1 generation seeds the first seeds from inbred plants this is where the hybid vigor and disease ristance is most strongly expressed in the off spring. As for transgenic vegtables there are none on the market except for sweet corn.


Once my plants reach a good size, I stop watering completely until they wilt somewhat. This, supposedly tricks the plant into thinking it is about to die, thus producing more flowers for future propagation.

Kelly Smith

Hi Bill,

Yes, a plant tries to reproduce when put under stress and death seems imminent, but it’s risky to do this and it could make the tomato more susceptible to disease and pest problems. Keeping the tomato strong and healthy where it can better support the fruit it produces is a better route. Let the tomato run its natural course. For more information on growing healthy tomatoes, visit our Growing Tomatoes page.

Happy growing!
Kelly, Bonnie Plants

Timothy Marshock

I bought some Bradley Heirloom plants. The plants are now beautiful and healthy 2 feet tall with many blossoms but no tomatoes. The soil is very rich, well drained and they are in full sun. Is there something that you recommend to make them bear fruit?
I would appreciate your suggestions in this matter.

Mary Beth

Hi Timothy,
Where are you located and how’s the weather been? Blossoms have to be pollinated and “set” to begin producing fruit, and sometimes high temperatures (above 85 degrees) deter that. You can also help the flowers out by taking a Q-tip from bloom-to-bloom or lightly shake the stems to encourage pollination. Or, it could just be that they are about to set fruit and you’re being a happy, impatient gardener! Give it a little time…Definitely let us know how it grows. ~Mary Beth, Bonnie Plants

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