Choosing ripe watermelons from the local grocery store or farmer’s market is one thing, but what about knowing when to pick watermelon if you’ve taken the time to grow your very own? There are several distinct signs to take note of in order to harvest a perfectly ripe watermelon from your garden. Seeing these signs and acting accordingly can make all the difference between picking too soon, picking too late, or harvesting right on time—and enjoying the sweetest watermelon you’ve ever tasted as a result. Understanding exactly when to pick watermelon is especially important because the sweetness of a watermelon won’t improve once you’ve removed it from your watermelon patch.

How long does watermelon take to grow?

In part, when to pick watermelon for maximum sweetness will depend on the variety you’ve chosen to grow. Hoping to walk away with a record-setting behemoth? Watermelons like Congo can weigh in at 40 to 50 pounds each and may take up to 100 days to go from seedlings to maturity. On the other end of the spectrum? You may be able to harvest ripe melons from the very popular Sugar Baby variety in as few as 75 days.

Of course, some watermelon growers choose to get a head start on watermelon season by starting seeds indoors two to three weeks before the last average frost date for their area. Doing this ultimately can impact when to pick watermelon fruits. So can the timing of the appearance of a plant’s female flowers and the availability of bees and other area pollinators to transfer pollen from male flowers to female ones. To ensure good fruit production, you may want to hand-pollinate your crop.

Factors affecting the timing of watermelon ripening

If you’re a new watermelon grower, pay attention to the following factors since they can affect when to pick watermelon:

• Water—Offer plants about two inches of water per week while they’re young and closer to one inch of water per week after they’ve set fruit. Occasional, deep watering with a soaker hose or drip irrigation system is preferable to many frequent-but-shallow watering sessions. Incidentally, whether the varieties you choose produce oval-, round- or oblong-shaped fruits, they should look fairly symmetrical. Still, let’s say a watermelon you’ve got your eye on has a lot of irregular bumps. This can be a good indication that it’s too soon to harvest and there may be a problem with the melon’s water content.
• Soil conditions—Rich, well-draining soil is best. Not sure about the quality of your planting site? Perform a soil test and amend with compost or other organic matter as needed. You can also periodically apply an organic, slow-release fertilizer.
• Sunlight and temperature—For a good watermelon crop, you’ll need a spot that gets at least eight hours of full sun daily. Soil temperatures should consistently be at least 60 degrees F (16 degrees C) as well. Don’t rush watermelon seeds or seedlings into the ground too early in spring. They are not frost tolerant.

Why picking watermelons at the perfect time is important

Professional watermelon farmers can easily spot the characteristics of a perfect melon, so you can be fairly certain that the fruits they send to market are ready to eat. But imagine after months of effort in your home garden, you think you’ve harvested the perfect watermelon only to discover it wasn’t really ready to pick just yet. 

If you want to grow and enjoy the very best watermelons, your harvest timing is critical. Here’s why: crops like cantaloupe, tomatoes, or that bunch of bananas on your kitchen countertop continue to ripen even after they’ve been harvested. But, once a watermelon is removed from its vine, the ripening process stops. (Incidentally, this is true for most varieties of honeydew melons as well.) That’s why knowing when to pick watermelon for maximum ripeness is so important. 

When to pick watermelon based on the firmness of the skin

How a watermelon feels can offer a clue about its state of ripeness. To test, grip the outside of a watermelon and lightly squeeze. If it feels rock hard with absolutely no “give” it might require more time on the vine. If, on the other hand, it feels downright squishy, that melon may be overripe and mushy inside.

When to pick watermelon based on the weight of the fruit

Because these fruits have a very high water content, a ripe watermelon will feel rather heavy when picked up. Just how heavy depends on the type you choose to grow. Recall that a single Congo watermelon can weigh as much as 40 pounds or more. Once ripe, smaller melons like Sugar Baby should weigh closer to 10 to 12 pounds each.

The sound of a ripe watermelon when the rind is tapped

When you thump on the outside rind of a ripe watermelon, you should hear a slightly hollow, deep sound. If the watermelon isn’t quite ready, the sound will be more solid and less resonant. (Because these sounds sometimes can be difficult to differentiate, it’s not a good idea to rely solely on this method.)

When to pick watermelon based on the yellow spot where it touches the ground

If you gently pick up a watermelon in the field and look at its underbelly, you should see a lighter colored area. This is the place on the melon’s exterior which has been resting on the ground while the fruit develops. Known as the “ground spot” or “field spot,” it will have a creamy yellow color when the watermelon is ready to pick.

When to pick watermelon based on the condition of the vine

The condition of the portion of the vine that’s near the watermelon in question can also be a good indicator of ripeness. Look closely and you’ll notice a curly tendril growing along the vine where the stem of your watermelon is attached. Over time, what begins as a bright green curlicue will die back and dry out. Bingo! If you want maximum sweetness, that dried-up tendril is a great sign for when to pick watermelon.

How to harvest a watermelon

It’s worth noting that, unlike many other fruits, ripe watermelons do not reach a stage that growers refer to as “full slip.” If you’ve ever grown cantaloupe, for instance, you know that these easily slip off the vine when they’re ripe and ready to eat. At full slip, a ripe cantaloupe can be separated from the vine with very little effort from you.

Watermelons do not have this quality and tend to hang onto their respective vines. So, when you think a watermelon is ready to pick, you’ll need to use shears, a knife, or garden snips to remove it. Then, after cutting into your watermelon, place any leftovers in an airtight baggie or container and refrigerate.

A vine time

Whether you’re growing specialty heirloom varieties, hybrids, or extra small watermelons, figuring out when to pick watermelon for the best flavor is easy once you know what you’re looking for. (Remember that harvesting a watermelon at just the right moment matters because, once it is picked, the watermelon won’t continue to ripen!) Some common signs of ripeness include a pale yellow or cream-colored field spot and a dried-up tendril along the vine near your watermelon’s stem. A ripe watermelon will also feel heavy when picked up and it will make a deep, hollow sound when thumped on. Finally, if you give it a squeeze, the melon should feel firm with just a little “give.” If it feels mushy, you may have waited too long before picking.

Find a watermelon in your patch with these ripeness cues? Then it’s time to separate it from its vine. Use shears or a sharp knife and cut it open to reveal just-right flesh that’s crisp, refreshing, and oh-so-sweet. 

For more information on growing melons and related crops, be sure to read these articles:

• How to grow cantaloupe from seeds
• Growing watermelons in containers
• How many watermelons grow on each plant