How Do You Gauge Peak Watermelon Ripeness?

If you've never grown your own watermelon before, you're in for a mouthwatering treat.

You're also in for a bit of a wait. A watermelon plant requires anywhere from 80 days (for smaller melons like sugar babies) to 120 days to mature and bear fruit. Not only is fruit one of the very last steps in a plant's life cycle, but we're also talking about bowling-ball-size fruit here.

Knowing when to harvest your watermelons can be a little tricky. Here are five signs to look for to harvest your melons when they're at their juiciest and packed with flavor.

How Long Does a Watermelon Plant Take to Grow?

It's always a good idea to check the back of the seed packet to know how long something takes to produce. On the day of planting, count forward on a calendar to mark when you might expect your first harvest.

When that time is drawing near, begin checking your fruits for signs of ripeness.

Now, keep in mind that the "days to harvest" given on the seed packet assumes the plants are being grown under their ideal conditions. Watermelons need about 10 hours of sunlight a day, warm to hot temperatures, consistent moisture, and tons of extra nutrients to grow and produce. Things like cold weather, inconsistent watering, and lack of sunshine can really slow their production.

To keep your watermelon plants happy and productive, make sure you're giving them about one inch of water per square foot of plant growth a week and applying a phosphorus-rich fertilizer every one to two weeks. I also like to spread out the vines a bit so that each and every one of those watermelon leaves can soak up as much sunlight as possible.

The Tendril Attached to the Watermelon Fruit Turns Brown

The first sign is easy to make note of while you're tending your garden. The curly tendrils closest to the fruit will dry up. You may even notice a crack appearing at the base of the stem that connects the fruit to the watermelon vine. Once a couple tendrils look shriveled up and dead, that's a good sign that homegrown watermelon mint salad is in your near future.

The Bottom of the Melon Turns Buttery Yellow

Your watermelon will be at its vine-ripened peak of flavor and nutrition when it has what we call a field spot. The field spot forms where the bottom of the fruit has been resting on the ground, and it starts off a light green or white and then turns a buttery yellow. Wait until you see that more yellow color to harvest your watermelon.

Note: Some darker watermelon varieties have field spots that turn deep yellow or orange, so make sure you know what to expect for the type you're growing.

The Skin Becomes Dull

The skin of a ripe watermelon will have a dull finish and might even feel rougher to touch. Resist the temptation to harvest when it's still nice and eggplant-shiny, or you might end up with an underripe melon.

You might also notice more of a color difference between the darker green and pale green stripes in the netting pattern as your fruits near their peak ripeness.

Side note: Watermelon webbing might look like a blemish on your fruit, but it's a sign that things are sweetening up!

The Melon Passes the Thump Test

If you tap on the watermelon with your knuckles, it should sound hollow if it's nice and ripe.

The Fruit Feels Heavy for Its Size

When a watermelon is perfectly ripe, it's mostly made of water. That means it'll become dense and really heavy for its size. I harvested a 20-pound watermelon once that took my breath away trying to carry it inside!

While we're talking about size, you may see signs your melons are ready for harvest when they're still much smaller than the ones you see at the grocery store. That's okay. Homegrown melons are typically on the smaller side.

How to Harvest Your Watermelons

As soon as you begin noticing signs that your watermelons are just about ready to harvest, you'll want to stop fertilizing them. This helps make each fruit as sweet and nutritious as possible. You'll also want to slow down your watering, then stop altogether the week leading up to your watermelon harvest. Again, the goal here is to sweeten up the fruit. It also makes the flesh crisp.

To harvest a melon, use a sharp knife or clean pruning shears to cut the watermelon from the vine. Leave a couple inches of the stem attached to prevent rotting after harvest.

Make sure to harvest any remaining watermelons before frost arrives.

What Happens If You Pick a Watermelon Too Soon?

If you're a little too eager to crack open your first watermelon of summer or if frost is on the way in the fall, you might find yourself harvesting watermelons that aren't quite ripe yet. I'm impatient and typically harvest my melons when they're about 90% ripe. Unlike some fruits, your watermelons won't continue to ripen once they're picked.

Unripe watermelons are perfectly edible at any stage. Just keep in mind they won't be nearly as sweet or as juicy as a ripe melon. They also won't have quite as many nutrients. Watermelons have the highest concentration of antioxidants like beta carotene and lycopene when they're fully ripe.

Near the end of the growing season, if you still have fruit maturing on the vine, you can try to speed up the ripening process. What you do is prune the tip of each vine. It's just like topping off your tomatoes. This tells the plant to stop growing and instead put all its effort toward finishing the fruit. Try to plan ahead so that your fruits still have 3 to 4 weeks to ripen before your first expected frost.

What Happens If You Leave a Watermelon on the Vine Too Long?

As always, the ideal time to harvest something is the minute it's ready, even if it's much smaller than the veggies you're used to seeing at the grocery store. If you leave a watermelon on the vine too long, the fruit becomes more mealy than crisp and refreshing. You also increase the chance that something goes wrong (pest pressure, unexpected cold snap, stress from inconsistent watering, etc.) the longer you let something hang out on the plant. Coming out to find this watermelon split open was a huge bummer.

If you go out of town or something and come back to a watermelon long past its prime, you can always cut it open and save your own watermelon seeds.

How Many Watermelons Can You Harvest from One Plant?

It depends on the watermelon variety you're growing, but you can typically expect to get 2 to 4 fruits per plant. Another factor that might impact your yield is whether or not you pruned your plant down to one main vine or kept extra vines. If you kept all the extra vines, you'll likely get more melons, but they'll be a little smaller.

My Favorite Watermelon Recipes

Watermelon and basil are, in my opinion, the flavors of summer, so I love to see how many different dishes I can include them in.

Here are some of my favorite ways to use up watermelon harvests:

• Whip up Martha Stewart's watermelon feta salad with tons of basil.
• Make PlantYou's strawberry watermelon popsicles.
• Use watermelon as a substitute for tuna in this vegan ahi tuna bowl.
• Blend up your own watermelon juice.
• Try this strawberry watermelon smoothie recipe from Simple Green Smoothies.
• Make a watermelon cucumber salad for dinner.

How to Store Watermelon from the Garden

The best way to keep watermelon is uncut and unrefrigerated. Your fruits should stay fresh for about 2 weeks this way. If you cut your watermelon open, then you'll need to store anything you don't enjoy immediately in the fridge. Wrap your cut pieces tightly in plastic wrap.

Enjoy the Sweetest Watermelon Harvest Ever!

Fully ripe garden-fresh watermelons are so sweet and crisp. Remember that when you're feeling impatient after waiting all summer for your first harvest. I promise it'll be worth it! When the watermelon juices are running down your chin, you'll know you've arrived in kitchen garden heaven.