Watermelon is a joyful, quintessential sign of summer and a fun plant to grow from seed, but it begs the age-old question: is it a fruit or a vegetable?

Our featured watermelon variety: Crimson Sweet Seed

Is Watermelon a Fruit or a Vegetable?

Watermelon PlantsThe answer to the question depends on whom you ask. Botany experts will tell you that because a watermelon develops from the ovary of a flowering plant and contains seeds, it is the very definition of a fruit. Remember, by the way, that’s the same reason a tomato is a fruit and not a vegetable.

But others—mostly chefs and the state of Oklahoma (which declared it its official vegetable in 2007)—stand firm that watermelon is a vegetable. Their argument is that since watermelon is harvested from the field in a similar fashion to squash and pumpkin, that makes it a vegetable. Dubious? So are we. But no matter; watermelon is delicious no matter how it’s classified. Oh, and one last tidbit regarding the fruit-vegetable debate: apparently a fruit can be a vegetable but a vegetable can’t be a fruit. Go figure.

Interesting Facts About Watermelon Plants

Fact 1
Watermelon—Citrullus lanatus—is a member of the cucumber—Cucurbitaceae—family of which gourds are a member as well. If you’re familiar with watermelon’s growth habit, you’ll agree this makes sense, given that all the plants in the family grow on trailing vines.
Fact 2
Over time, people have come up with various, creative ways to consume and use watermelon in addition to the tried and true method of just slicing and serving it. For example, some use it to create edible sculptures; others use it as a floating pool toy, and still others use it to make potent cocktails or a delicious summer punch. Delicious AND fun’that’s probably why its mere mention can make people smile.
Fact 3
There is evidence that watermelon existed in Egypt and neighboring regions thousands of years ago. Archeologists found watermelon seeds among the remnants of a 5000-year-old settlement in Libya. What’s more, seeds and paintings of watermelons have been discovered in ancient Egyptian tombs, including King Tut’s. But, there’s also evidence that watermelon’s wild ancestor—a bitter fruit with hard, pale-green flesh—was a far cry from our familiar, favorite, summer fruit. which is juicy, sweet and delicious. Evidently, it took many centuries to evolve into the juicy, sweet and delicious fruit (or is it vegetable?) we enjoy today.

Watermelon Gardening Tips

Difficulty
Difficulty

Easy-Moderate IF your growing season is warm and long, and you have space.

Sun
Sun

Full sun.

Water
Water

Watermelon are heavy drinkers and feeders. Regular watering is key.

Soil
Soil

Well-drained soil enriched with compost. The soil temperature must be at least 70°F. The warmer it is, the faster watermelon seeds will germinate. At 70° F, seeds will germinate in 10 days; at 90°, it may only take 3.

Air
Air

Watermelons like it hot!

Timing
Timing

Start watermelon seeds indoors about 4 weeks before your last anticipated spring frost; transplant seedlings outdoors once it’s consistently warm outside. Or, if your growing season is long enough, direct sow seeds in the outdoor garden two weeks after the last frost.

Planting
Planting

Sow seeds 1 inch deep. Space according to seed packet instructions.

Germination
Germination

3-10 days.

Feeding
Feeding

Seeding to maturity generally takes at least 80 days.

Mulch
Mulch

Add rich compost or organic fertilizer at planting time and again every six weeks.

Pests & Diseases
Pests & Diseases

Add mulch as the seedlings develop to retain moisture and warmth and discourage weeds.

Special Considerations
Special Considerations

Young watermelon plants are susceptible to cucumber beetles. You can protect them with row covers as long as you remove them to allow for pollination when flowers appear.

Companion Plants
Companion Plants

Good companion plants are marigolds and nasturtiums as they both deter the potentially-problematic cucumber beetle.

Container-Friendly
Container-Friendly

Yes? If you have a large enough container (at least 5 gallons) and enough space to accommodate the watermelon’s spreading habit.

Harvesting Watermelon

Harvesting You can harvest watermelon when it appears to have stopped growing (after 80 days) or its underside starts to yellow and/or the stem starts to shrivel. It will last about 3-4 weeks after being cut from the vine.

Growing Watermelon—Highlights

  • Watermelon is a joyful, quintessential sign of summer and a fun plant to grow from seed!
  • It’s easy to grow if you have long, hot summers where you live.
  • Watermelon is slow-growing, requiring at least 80 days to reach maturity.
  • Watermelon plants spread on vines and need a lot of room to grow.
  • Did you know that some consider watermelon to be a vegetable?
  • Watermelon is made up of over 90% water.
  • Though it’s mostly water, it packs some serious nutrients including vitamins A, B6, and C, as well as lycopene, antioxidants and amino acids.

Here at Bentley Seeds, we want to set you up for success. Our growing guides are designed to give you all the information you'll need to start growing from seed, in an easy-to-digest format.

We also encourage you to print out a copy as a handy reference in your garden.