By Andrew Messinger
They’re the space hogs of the vegetable patch. Their vines can grow 20 feet long and they can weigh anywhere from 10 to 50 pounds each (much like the size of a small pig), but their fruits are marvelous and these giants are considered to be the ubiquitous culmination of a summer picnic.
Probably originating in the Kalahari Desert region of Africa more than 5,000 years ago, botanists think the original ancestors of our modern watermelons are still growing there. We think they moved with trade through Egypt, and we know that they were cultivated by the Romans: hieroglyphics on the walls of Egyptian buildings tell stories of their harvest and there is indisputable evidence that the fruits were cultivated in the warmer Mediterranean areas.
First documented in America in Massachusetts in 1629, the Confederate Army boiled watermelons to make molasses for cooking. One of the oldest cultivated varieties was developed in South Carolina as a commercial crop—the classic Charleston Grey.
If there’s a fruit that all kids love, this is it. They can slice it, dice it, eat it right from the garden, and oh yes, the seeds are great fun to shoot when pressed between the thumb and forefinger.
But even better, the seeds are large enough for kids to handle and plant, and growing watermelons makes a great summer project. A long summer project. Even the smaller varieties can take 80 days to harvest from the time they germinate.
This means that seeds need to be started indoors around mid-May. They get planted out in the warm garden in late May and harvesting begins and runs through August.
Our modern watermelons are classified in one of four ways: picnic, icebox, seedless and yellow/orange flesh types. Picnic types are the larger melons that can run from 15 to 50 pounds. Icebox types are smaller versions and weigh in from 5 to 15 pounds. Seedless types are, you guessed it, seedless, and not as much fun for kids but easier to use in salads and best for those with little patience for digging the seeds from the flesh before eating. Lastly, there are the yellow/orange flesh types.
In the 1990s, seedless, or triploid, watermelons came onto the market. They now account for nearly 50 percent of all watermelons commercially sold.
For home gardeners and those of us who garden in the cooler climates, we can choose early-maturing watermelon varieties, such as Shiny Boy, Golden Crown or Yellow Baby. These mature in 70 to 75 days, which cuts 10 days from the traditional maturity times.
For smaller fruits, and ones that may be more compatible with smaller humans, you can try something like the 8-pound Seedless Sugar Baby Hybrid. Or go for the glory-and-sow seeds for an extra large whopper, such as the 30- to 35-pound Congo.
Heirloom fans may want to try Moon and Stars, which was introduced in 1926. This one has deep green skin, speckled with tiny yellow stars and quarter-sized moons. For an updated hybrid of Moon and Stars, you can try the seedless Harvest Moon.
Now at this point I know someone wants to know how you can grow a seedless watermelon. After all, in order to grow a watermelon, you need a seed. And if the watermelon you’re growing is seedless, how can you grow another watermelon from it?
It’s a secret.
To grow a watermelon you need lots of space and lots of sun. The vines (which really can grow up to 20 feet long) enjoy rambling and can be coaxed around other plants.
Watermelons like a soil amended with lots of compost. Composted cow manure is perfect.
The seeds are planted in hills or mounds with eight to 10 seeds per mound. The seed is simply pushed into the soil about an inch deep and the hills should be about 3 to 4 feet apart. If you’re planting rows, they should be 8 feet apart.
When the seeds germinate, thin them to the three best plants per hill. They do really well on black plastic mulch.
Seeds can be started indoors two weeks before outdoor planting, but start them in peat pots as they resent transplanting. Garden centers also sell them as starts later in May. Heed this advice for productive plants: don’t set them into the garden until the soil is warm at the end of May.
A high nitrogen fertilizer should be worked into the soil before planting. The plants will need to be fertilized again during the growing season by working a balanced fertilizer into the soil when the vines begin to ramble and again when melons are set.
The hills need to be kept free of weeds, which can be done by shallow hoeing or using a layer of mulch after planting. Or, before planting, set down a black plastic mulch to cover the ground and then insert your seeds through holes made with a sharp pencil or knife.
For smaller gardens, there are varieties such as Sugar Baby that produce smaller fruits on vines that are less than 4 feet long. Faerie has vines that are only 10 feet long. Shorter vines equal smaller fruits but still yield the same great taste.
Want super sweet fruit? Dissolve 1 tablespoon of borax in a gallon of water and spray the solution on the foliage and at the base of the plants when the vines begin to ramble.
It’s important to remember that watermelons produce fruit only when the flowers are pollinated. This has to be done by insects, usually bees, though some home growers like to do the pollination on their own. To do this you’ll have to identify the male and female flowers so do a little reading before you try it.
Knowing when your melon is ripe is a bit of an art. Experienced gardeners can do a thump test and they know immediately.
For beginners, watch the tendril closest to the melon stem. The tendril is a modified leaf or stem in the shape of a slender, spirally coil. When it turns brown and dries up, the melon is ripe. The problem with this method though is that with some varieties the tendril drops off more than a week before the melon ripens.
For best results, you need to learn how to thump. This slapping or tapping results in a hollow sound when the fruit is mature. But between the tendril and the thump you and the kids will be able to figure it out.
Watermelons mature rapidly during hot weather. Most will ripen about 32 days after blooming.
The surest sign of ripeness is the color of the bottom spot where the melon sits on the ground. As the melon matures, the spot turns from almost white to a rich yellow. The fruit will also lose the powdery or slick appearance on the top and will take on a dull look when fully ripe.
Growing melons, big or small, red or yellow, can be lots of fun. Every kid, and every gardener, should try to do it at least twice.