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Have you ever anxiously sifted through a bin of watermelons at the grocery store, wondering which one was the ripest? Or have you grown your own watermelon at home, and been unsure when was the right time to pick the perfect melon?
Watermelons are ripe when they have dull skin and a rich yellow spot where the melon ripened in the field. In the garden, use the “thump test” and take notice of brown, dry stems to recognize exactly when a mature watermelon is ready to be harvested.
Read on to learn how to pick a perfect watermelon at the grocery store or off the vine.
How to choose a ripe watermelon
Picking a ripe watermelon doesn’t have to be difficult. While traditional gardening knowledge advises thumping a watermelon with your knuckles and listening for a hollow thud, the easiest way to tell if a watermelon is ripe is actually by appearance. Look for melons that have dull, waxy skin and the tell-tale yellow spot.
The first thing to look for when picking a watermelon is the “field spot,” or the place where the watermelon rests on the ground. A rich, yellow color is a sign that the melon had time to ripen naturally on the vine, whereas a pale or cream-colored spot is a dead giveaway that the melon was picked before it fully matured.
One piece of traditional gardening knowledge you’ve probably heard is to tap the melon with your knuckles and listen for a hollow thump. The thump should sound deep and rich, signaling that the melon is mostly water, ready for eating. Skip any watermelons that have a high-pitched or dull sound, as these melons will be not quite ripe and overly ripe, respectively.
Dense, heavy watermelons contain higher water content – and are therefore sweeter – than similar-sized melons with a lighter weight. Ideal weight isn’t always the most reliable characteristic, however – a really heavy melon might be overripe, and a lighter melon might not yet be mature. Use weight in conjunction with other signs like the field spot to judge a watermelon’s ripeness.
Dull-skinned symmetrical melons
While it may be tempting to pick the prettiest, shiniest watermelon, dull-skinned melons are likely to taste better than the nicer ones look. Dull watermelons have had time to age in the garden, storing up sugar underneath their thick rinds.
Watermelon skins should have just a little bit of give to them – if the skin has no give when you press on it, give that melon up. Steer clear from any watermelons whose skin feels soft to the touch or hints at mushiness underneath the rind.
If possible, always choose a symmetrical watermelon over an oddball. Any irregularities are a sign that the plant underwent some water stress, either too much or too little. Play it safe with a beautiful watermelon guaranteed to be delicious.
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When to pick a watermelon for peak sweetness
If you’re growing your own watermelons at home, you might be wondering about the perfect time to pick them. The previous pointers work as well in the garden as in the grocery store, but there are a few additional techniques that only growers are privy to.
Days to maturity
A dependable metric to use when estimating watermelon ripeness is the days to maturity listed on the seed packet. Most varieties of watermelon mature in 80 days, so you can start checking for ripe melons as early as day 75. After this point, check for ripe melons every day – once the first melon is ready to harvest, the rest will soon follow!
Another dead giveaway of a ripe watermelon is when the curly tendrils on the vine turn from green to brown. This is a sign that the plant has completed its life cycle, and once the vine dies back the watermelon will be as ripe as it’s ever going to get. Go ahead and make the cut, leaving at least two inches of the vine on the fruit.
How to grow the perfect watermelon
Watermelons, along with cucumbers, squash, pumpkins, and other melons like cantaloupe, are members of the cucurbit, or gourd, family. Gourds like these are heat-loving annual vining vegetables that thrive in well-draining, fertile soils.
Pick a perfect site
It’s not difficult to grow watermelon, but you will want to put a little forethought into where you will grow these wild and unruly vining melons. Unless you’re growing a compact variety, make sure you have enough space for these wild and unruly vines to sprawl. Watermelons can easily overrun your garden, so give them a block of their own or plant them along the outside border and train them to grow away from the rows.
Choose a planting site that receives full sun, or between six and eight hours of sunlight a day. If you have an area of your garden that gets more sun, watermelon plants will grow even faster and produce sweeter fruits.
Prep with compost
Watermelons are heavy feeders, so be sure to amend the planting area with compost and fertilizer before you plant. Organic compost adds essential nutrients and serves the additional purpose of improving the texture and aeration of native soils.
Like most fruits and vegetables, watermelon vines prefer a slightly acidic soil pH between 6.0 and 6.8, so you might want to use a soil tester if you suspect your soil might be a little more alkaline.
Sow seeds in hills
Sow watermelon seeds in small hills – the mounded soil improves drainage and warms the soil up faster than the surrounding ground. You can transplant watermelon seedlings, but the plants grow so quickly from seed that starting watermelon indoors isn’t really necessary unless your growing season is less than three months.
If you decide to start watermelon seeds indoors, sow two seeds each in four-inch pots six to eight weeks before your area’s last spring frost. Transplant seedlings a couple of weeks after your last frost date.
Watermelons need consistent watering to bear the juicy fruit that we love, but overwatering the plants will result in sickly plants with shallow roots. Give watermelons up to two inches of water each week, but reduce their water intake down to one inch once the vines start making fruit, so that the plants’ sugars will be more concentrated. Use a rain gauge to precisely measure how hydrated your watermelon plants are.
Storing field-ripened watermelon
Contrary to popular belief, watermelon does not ripen off the vine. When a melon is picked, that’s as ripe as it will ever be – so don’t rush your watermelons. Let watermelons mature in their own time and you’ll be rewarded with sweet and juicy fruit.
Once you’ve picked a ripe watermelon, you can store the melon at room temperature for two weeks. Once you’ve cut into a melon, wrap the open side in plastic and store in a refrigerator.
6 best-tasting watermelon varieties
There are four major categories that most watermelon varieties fall under – picnic, seedless, icebox, and yellow/orange. Picnic watermelons are the largest cultivars, weighing more than 16 pounds (7 kg). Seedless watermelons – like the name suggests – have little to no seeds. Icebox watermelons are small, personal-sized melons that are significantly more manageable, weighing between five and 15 pounds (2-7 kg).
Yellow and orange watermelons, as you might have already guessed, have different colored flesh than their traditional counterparts. Some icebox and seedless watermelons also fall under this umbrella – there are so many varieties of watermelons, it’s hard to define them all!
What follows are just a few favorite watermelon cultivars for eating and growing.
- Crimson Sweet
The stereotypical green-striped melon averages around 25 pounds (11 kg) and has bright red, sweet flesh with just a few black seeds. This treasured and productive heirloom matures in 85 days. You can buy Crimson Sweet Watermelon seeds from Baker Creek Heirloom Seed Company.
- Bush Sugar Baby
This heirloom icebox watermelon grows on compact vines that are perfect for small spaces and container gardens. Three-foot vines produce multiple eight-inch (20cm) fruits with sweet and juicy red flesh. Bush Sugar Baby is the perfect personal watermelon, and you can buy seeds from Burpee.
- Yellow Doll
An early and compact icebox variety that matures in 70 days. A beautiful melon with pale green stripes and a thin rind that gives way to delicious yellow flesh. Yellow Doll is a favorite with everyone, but especially gardeners in colder climates with shorter growing seasons. Purchase your Yellow Doll Watermelon Seeds from Harris Seeds.
- Charleston Gray
This unique oblong watermelon has a pale green outer skin and a crisp red inner flesh. This classic picnic fruit is an American heirloom, producing flavorful melons weighing between 20 and 50 pounds (9-18 kg) when ripe. Buy your Charleston Gray Watermelon Seeds from Baker Creek Heirloom Seeds.
- Orange Tendersweet
Another oblong-shaped fruit with orange flesh, this heirloom variety can grow up to 35 pounds (16 kg)! Orange Tendersweet is not a seedless variety, but the large black seeds are perfect for spitting contests. Burpee carries Orange Tendersweet Watermelon seeds.
- Triple Crown
A hybrid variety that combines excellent flavor with a seedless trait for the perfect eating watermelon! Triple Crown is an early maturing variety, and a productive one too, producing several 18 to 20-pound fruits (8-9 kg) throughout the season. Check out Park Seed for Triple Crown Hybrid Seedless Watermelon Seeds.
There’s no mysterious secret to growing and picking delicious watermelons – start with one or two of these quality varieties, plant them in fertile soil that sees a lot of sun, and you’ll be well on your way to growing this quintessential sweet summertime fruit.
Check out these must-have gardening products
You don’t need much to start gardening, but some tools and products will make a difference in how comfortable and effective gardening can be for you. Here are my favorites:
- Garden Trowel. A good garden trowel will last you many years. I love how sturdy this hand trowel from WOLF-Garten is, the metal doesn’t bend and it has a nice grip.
- Trimming Scissors. I use them for delicate pruning and harvesting all summer long, and they’re super handy. These Teflon Trimming Scissors are extra nice because they don’t rust as easily.
- Dutch Hoe. Dutch hoes may seem old-fashioned, but there’s nothing like a quick sweep through the topsoil to get rid of small weeds – no bending required. I love WOLF-Garten’s selection: this dutch hoe coupled with their universal handle.
- Grow Lights. These grow lights from Mars Hydro are super strong, yet dimmable, so they fit every stage of growth. They don’t put out too much heat and are very economical.
- Seedling Trays. There’s an art to choosing the best size for seedling trays so that it holds the perfect amount of water and gives the roots enough room to grow. These germination plugs are perfect when coupled with 1020 bottom trays.
- Liquid Fertilizer. You’ll need to feed your plants from the seedling stage, all the way to fruiting. This organic fish & seaweed blend is a very versatile option. Use it half-strength for young plants and full-strength for established plants.
Browse our list of tools, fertilizers & pesticides, indoor growing products and seed shop recommendations – we hope you find our selection useful and it saves you some time!