Seedless Watermelon

San Antonio Express News
Sunday, July 10, 2005

By Dr. Jerry Parsons

seedless watermelonHow watermelon came to North American shores, the origin and history of this vegetable, and the nutrition and how to harvest watermelons can be found at:

There is nothing that can cool your innards and soothe your displeasure with a hot summer day better than watermelon. Watermelon is the sweetest member of that vast family of 700 species called Cucurbitaceae.

I don’t know how many of you were raised in a farming community where watermelons were grown, but if you were, I can tell you the first memory you have when you see a watermelon. The fondest memory of your childhood experiences with watermelons was sneaking into your grandpa’s or neighbor’s field on a hot summer day, busting the biggest, ripest melon you could find and eating the “heart” or center out of the watermelon.

You didn’t seem to mind that juice running down your face and over your chin—that was living the “good life” and the best eating in the world. I can even tell you the name of the watermelon variety you enjoyed as a child–it was named Black Diamond. The reason you enjoyed that watermelon experience so much is because the center or “heart” of those watermelons didn’t have any of those pesky seeds–just pure, juicy watermelon.

Those were the good old days, but scientists have now improved the annoying seed-spitting problem and created watermelons which have all “heart” all the way to the rind. It is referred to as a seedless watermelon and it is sweeter tasting and firmer-meated than any Black Diamond that ever existed. This doesn’t mean these seedless watermelons will supercede your childhood memories–remember, half the fun was sneaking into the watermelon patch and eating the best part of the summer thirst quencher named watermelon. You also had more taste buds then!!!

Watermelon VertigoFor those who love watermelon but don’t want to engage in a seed-spitting contest with each bite. Seedless watermelons have an oval to round shape and can have either red or yellow flesh. A seedless watermelon may have some white seed-like structures that are edible. Don’t think just because these watermelons are seedless that all varieties are super-sweet and yield lots of watermelons. Nope! Every seedless variety is different and performs differently at each planting site.

So growers won’t have to do the testing, Texas Cooperative Extension conducts tests in all regions of Texas to see which seedless and non-seedless varieties perform the best in our conditions. The first of these tests were conducted at the Verstuyft farm over 30 years ago.

The Verstuyft Sales Outlet still sells some of the best watermelons in the area. Give them a call at 210-622-3423 before you go to insure that they have a good supply. Directions about getting to the produce stand can be found at:

Some of the results and images of previous watermelon harvests can be seen at:

When conducting these tests, we are often reminded of some historical warnings about eating too much watermelon. Mediterranean traders introduced watermelon to Europe where it was known as the “Turkie Melon.” Books from the 16th century show that the sweet thirst quenchers were not looked on with the delight we accord it today. John Gerard, writing in The Herbal cautions his readers that “This fruit should be eaten by Europeans with great caution when taken in the heat of the day, whilst the body is warm, colics and other bad consequences often ensue.”

If you will closely examine the data provided at the Watermelon Variety Trial website above, you will realize that each year we evaluated approximately 25 seedless varieties and 20 standard, seeded varieties. We use volunteers to do the taste tests and I try to make all testers understand that if you take one small bite of 45 watermelons, YOU HAVE LITERALLY EATEN AN ENTIRE WATERMELON! We began the watermelon taste testing with over 15 anxious volunteers —-by the time we cut the last sample, only 8 were left standing!

The obvious question asked about growing seedless watermelons is: “How does one obtain seed for growing a seedless watermelon?” Obviously, you cannot save seed from a seedless watermelon. So, where do the seeds come from?

Simply stated, the number of chromosomes (the threadlike bodies within cells that contain the inheritance units called genes) in a normal watermelon plant is doubled by the use of the chemical colchicine.

Doubling a normal (diploid) watermelon results in a tetraploid plant (one having four sets of chromosomes). When the tetraploid plant is bred back, or pollinated, by a diploid or normal plant, the resulting seed produces a triploid plant that is basically a “mule” of the plant kingdom, and it produces seedless watermelons. Seed of recommended seedless and seeded varieties can be purchased from the list at:

Whole, uncut watermelons will retain their texture and flavor for a week or more if stored away from sunlight at temperatures of 50 to 60 degrees F. Lower temperatures may cause a loss of flavor. Once sliced, the melons may be refrigerated for a few days.

A water content of 90% makes watermelon a low calorie sweet treat. A 4 by 8 inch slice has only 111 calories which means guilt free enjoyment along with the benefit of vitamins and minerals.

A wedge of watermelon provides two-thirds of the adult daily requirement of vitamin C. Compare to an orange, it contains nearly twice as much vitamin A and has more potassium,

So get to eating and help yourself cool off during this hot Texas summer!

For more information about the actual growing of seedless watemelons and some interesting images, see the second column for July entitled SEEDLESS WATERMELON at:

Dr. Jerry Parsons is a Professor for Texas A&M University and a Texas Cooperative Extension Horticulturist for over 30 years in South Central Texas. For more information on this or other horticulture topics, go to and our County Extension website at

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