Remember in the backyard spitting Watermellon seeds at each other at the summer picnics and then later to find that the Watermelon seed sprouted little Watermellon plants by the Fall. We dreamed about growing big ones and eating them all summer long but they never grew. Can You Plant the Seeds of a Watermelon You Ate?
Yes, Watermelons are one of the easiest seeds to collect and last up to 4 years if protected by frost. Start Indoors. Seeds will germinate and harvest into a hybrid fruit grown especially for a certain flavor, size or hardiness on the shelf as long as they stay warm/wet and the soil stays above 60°
Watermelon is a family favorite, especially in the summer. Try growing them this year for an even better experience. There are 3 ways to get watermelon started growing in your backyard to enjoy for the summertime.
- Transplant a few plants from the Garden Center.
- Start Watermellon seeds from Indoors.
- Use Direct Seeding in the Garden
Where Did Watermelon Originate From?
Watermelons probably originated almost 5,000 years ago in the Kalahari Desert of Africa where botanists have found its wild ancestors still growing. Watermelons migrated north through Egypt, and during the Roman era, they were cultivated and prized. Hieroglyphics on the walls of Egyptian buildings tell stories of their harvest. They were even buried with the Kings in their tombs in order to nourish them in the afterlife. Watermelons spread across the European continent particularly close to the Mediterranean areas where the climate was warmer.
The Confederate army boiled Watermellon to make molasses for cooking. In southern states such as the Carolinas and Georgia where watermelons flourish as commercial crops. Numerous varieties were developed, and variations of flesh color surfaced. By the late 1800s, the W. Atlee Burpee & Co. was developing its own watermelon varieties and selling seeds.
Starting Watermelon Seeds
Watermelon seeds can be one of the easiest seeds to collect and save from mature fruit. You can grow it anywhere in the U.S. Department of Agriculture plant hardiness zones 3 through 11. Although Watermellon seeds will germinate at a soil temperature of 60 degrees the optimum soil temperature is as high as 95 degrees for seed germination.
- Simply scoop the seeds out of a watermelon,
- Rinse them under water to remove any fruit pieces or fruit juices
- Let them air-dry on a paper towel. In general, watermelon seeds stay viable for approximately four years. Still, the longer you wait, the less your chances of optimal germination.
- For the best results, plant watermelon seeds as soon as you harvest them.
- When buying commercial packets of seeds, check the expiration date to ensure the four-year limit hasn’t passed
Many seeds require that the seeds be soaked for long periods of time. This benefits the seed before planting them by softening the outer seed coating and hastens germination. This won’t work well for watermelons because soaking watermelon seeds increases the risk of fungal diseases, such as anthracnose caused by the Colletotrichum legendarium fungus.
Start the Watermellon seeds Indoors
Watermelon seeds are extremely sensitive to frost and cold air and can be quickly killed off. If you’re planning on growing watermelons this year try and get a hold on the growing season in peat poys indoors. For the best results with watermelons, boost the fertility of their upcoming new home, and use 3 pounds of 5-10-10 fertilizer for every 100 square feet of planting space. They like warmer temperatures. It takes about 3 days for a watermelon seed to germinate in 90-degree Fahrenheit conditions. Approximately three to four weeks before the last frost date in your region. Once all risks of frost have passed, you can transplant the watermelon seedlings into the ground. This helps you to be able to enjoy the fruits of your harvest weeks earlier.
If you are planning to start seeds indoors, consider using a space heater or heating pad to increase temperatures. If growing the seeds outdoors, try laying black plastic mulch over the planting site to help absorb the sun’s heat and increase soil temperatures during the day, and in turn, speed up watermelon germination.
- Place in a sunny south-facing window or under lights to germinate.
- Make sure the area is warm day and night
- ideally, 80 degrees F. Use a Seedling Heat Mat if necessary
How to Germinate Watermelon Seeds
Watermelons need a long growing season as much as 80 days and warm soil for seeds to germinate and grow. Some other necessary elements that I have collected to growing Watermellon growing are:
- Soil Temperature should be at 70 degrees at planting time
- If you are germinating in the soil then sow seeds at 1 inch deep and keep well water until they germinate
- Sow watermelon seeds 1/2 inch deep
- Watermelon can be a space hog-Vines can reach as much as 20 feet- Plant where there is plenty of open ground
- Amend the soil in the garden with cow manure or any kind of organic compost
- Add a balanced fertilizer that is high in nitrogen.
- Sow 8 to 10 watermelon seeds in a hill, and push seeds 1 inch into the soil. Space hills 3 to 4 feet apart, with at least 8 feet between rows. Thin plants to the 3 best in each hill. Keep soil free of weeds by shallow hoeing or with a layer of mulch.
- Watermelons love the sun and love the heat
- Plant in rich well-tilled soil
- The seeds and young plants will need at least 1 inch of water per week to meet the goal of keeping the soil uniformly moist.
Choose a variety of Watermelon that is designed to produce large fruit, such as Crimson Sweet, Royal Majesty, Carolina Cross or Black Diamond are a few. Other watermelons are designed to grow smaller melons to save space in smaller spaced gardens. Avoid watermelons that are described as baby, icebox, bush, compact or space-saving, as these are indicators that the melons won’t grow as large as you want.
Most watermelon plants grow to a height of approximately 24 inches, and sprawl approximately 3 to 20 feet wide. The vine produces coarse, medium-green leaves, while the fruit can weigh anywhere from 10 to 20 pounds with marbled, solid, or striped skin.
When the Watermellon vines begin to ramble give the plants a dose of Boron that will help produce sweeter fruit. Dissolve 1 tablespoon of household borax in 1 gallon of water and spray foliage and the base of the plants. Some growers recommend growing short-season varieties such as ‘Million Bucks Hybrid’ or ‘Orange Sunshine Hybrid’ if your growing season is less than 90 days. A Watermelon that is petite in size is called an Ice Box Watermelon which grows to full size in 70- 80 days and is named because of how it fits on a shelf in the refrigerator.
Watermelon Plant Not Growing
The worst enemies for a Watermellon in your garden are Cucumber beetles and vine borers. Use an insecticide such as Sevin or use Bacillus thuringensis for organic control. Floating row covers work, too, but they should be removed when watermelon plants start to bloom, at which time pollinating insects need to be allowed to reach the flowers.
Identifying Cucumbers Beetles- Some signs of the Cucumber Beetles being in your garden are the stems of your seedlings are being eaten off, leaves are yellowing and wilting, and holes are appearing, you may have a striped or spotted cucumber beetle problem. You may spot them from early April through June and feed on seedlings right as they emerging. Then their larvae feed on the roots of the host plants.
As they grow into adults from mid-July to September, the beetles will once again feed on the leaves, vines, and fruit of plants that survive, leaving deep marks in the rind. You can recognized adults as 1/4 inch long with striped bodies. They have a yellow and black abdomen with a dark-colored head and antennae. Spotted cucumber beetles are the same length but have 12 black spots on a yellow abdomen. The larvae are worm-like, white, dark-headed, and have three pairs of legs on the thorax.
Vine Borers- The squash vine borer, Melittia cucurbitae, is native to Missouri.
It is a serious pest of both summer and winter squash. The insect will also attack cucumbers, pumpkins, muskmelons, and watermelons. The first symptom is generally wilting of part or all of the plant. At the base of the plant, moist, sawdust-like debris (frass) can be seen piled outside small holes in the stem. If the stem is split lengthwise, frass and one or more fat, white caterpillars with brown heads can be found tunneling in the stem.
They live 1-2 inches below the surface. They are about 1/2 inch in size and have a wasp-like appearance. They have hind legs that are orange and black. The adults emerge from mid-June to July. They will lay brown-reddish eggs in rows or clusters. Their larvae live in the stems and will burrow over the winter in the soil.
Watermelon Growing Tips
It’s important to water your Watermellon garden twice daily. Do this or check to make sure the top 2 inches of soil stays moist, if not then water more. Do this for the first 5- 10 days during the first part of the growing stage the germination stage. Then once the plants are established water once daily.
- Use enough irrigation to ensure the soil stays moist down to a depth of 6″
- Keep this watering scheme throughout the crop’s life. If you don’t keep a scheduled watering scheme this could cause problems like stress and that can cause poor fruiting or cracked fruit in this water-loving plant.
- Keep the garden area weed-free area around your watermelons by hand-pulling weeds on an as-needed basis.
- Don’t Cultivate with a hoe or similar tool which can disturb this plant’s shallow roots.
- Fertilize the watermelons a second time when the first fruits start to appear, applying 1/2 pound of 33-0-0 fertilize for every 50 feet of watermelon row.
How To Know If a Watermelon Is Ready To Eat
- All depending on what kind of variety of Watermelon you are growing depends on when to harvest. It’s normally somewhere between 75 to 90 days after planting. The best way to know when to harvest is to recognize when the Watermellon is perfectly ripe which is hard to do. A watermelon is harvest-ready when the underside of the fruit turns yellow and when the stem of the fruit turns brown.
- Another way favored by many gardeners is to watch the tendril closest to the melon stem. A 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 trouble with this method is that with some watermelon varieties, the tendril dries and drops off more than a week before the melon is fully ripe. Slapping and tapping or thumping are other common methods used to determine ripeness, but they are not always the most accurate methods to determine ripeness.
- One of the surest ways to see the signs of ripeness in most varieties is to examine the color of the bottom spot where the melon sits on the ground. As the watermelon matures, the spot turns from almost white to a rich yellow. Also, all Watermelons lose that slick appearance on the top and take on a dull look when they are fully ripe.
Some people will sprinkle some salt on their watermelon, but it’s probably thought of as a cure for poor tasting store-bought melons and certainly not necessary for home-grown. If the seeds present a problem, grow seedless watermelon varieties like ‘Seedless Sugar Baby Hybrid’ or ‘Orange Sunshine Hybrid’. A cut melon, if covered with plastic wrap or aluminum foil, will keep several days in the refrigerator.
Watermelon With Salt Benefits
Salt makes Watermelon sweeter by putting salt on it. The salt will develop a contrast between the sweet and salty which makes the sweetness of the Watermelon stand out. Watermelon has a subtle type of sweetness because of the water content in the Mellon. This is different than a strawberry or a smaller type of fruit where the flavor is concentrated and more intense. So the salt will make it seem stronger. Salt also makes you salivate, which will make the watermelon seem even juicier than it is on its own.
The trick to success is to only add a small pinch of salt and to evenly scatter it over the whole piece of melon. If you add too much salt, you’ll drown out the melon’s sweetness and you’ll have to start over with a fresh piece. Southern folks have been using the Salt & Watermelon combination for a long time for the perfect type balance in sweet & salty like with Carmel & Salt ice cream. It’s really good and being from Philly I was new to it but now I use sea salt on Watermelon and love sea salt in Carmel fudge and ice cream.
How Do You Grow Seedless Watermelon
Seedless Watermelons are more difficult to germinate than regular melons so start more seeds indoors than you would normally. The best way to start them is to keep them in peat pots indoors until they germinate. Once they’re transplanted into the garden, follow the same directions as for seeded watermelons. Seedless watermelons need pollen from a seeded type to produce, so you must plant both kinds near each other. Here’s what you need:
- Seedless watermelon seeds
- Seeded watermelon seeds (choose a variety with a different colored rind than the seedless so you can easily distinguish the two types)
- Peat pots or eggshell planters (see note below)
- A growth medium or fertilizer mix
You need both types of plants and seeds because seedless Watermellon does not produce enough pollen to make fruit. The seeded Watermelon fruit is sometimes referred to as the pollinator cultivar, which provides supplemental pollen. Some of the best anthracnose resistant varieties of seedless watermelons are Crimson Sweet, You Sweet Thing Hybrid, or Summer Sweet 5032.
Start the Watermelon Seeds-
Use Peat Pots with a greenhouse growth medium then moisten soil until the extra moisture runs off. Keep them warm from 85 degrees to get the pots warmed and ready for the seeds-plant the 1 inch in the warmed soil-Plant the tip of the seed at a 45 to 90-degree angle to prevent the seed coat from adhering to the cotyledon. Cover them with moist soil and keep warm (85 degrees Fahrenheit) for 48 hours, and then move them to a cooler environment for germination and seedling development.
Germination of Seeds
- Keep at temperature 70-75 degrees and no colder than 65 degrees at night
- The fertilizer charge in the growth medium should provide enough nutrition during this stage, but fertilize with a 100 ppm nitrogen concentration at two other stages: the appearance of the first true leaf, and the second true leaf.
- Seedling development takes about four to six weeks.
- Hardening Off the Seedlings-Prepare the plants about seven days prior to their transplant to the garden (also known as hardening off the plants). Lower the temperature where they are during the day or set the plants outside. Bring them in each night. Water sparingly, if at all.
Prepare the Garden Patch
- For the best pollination results, plan a garden layout that allows you to plant the pollenizer variety in the outside row and then every third row.
- If you are growing watermelon in a small garden plot, try alternating seedless and seeded plants in a row, but remember that the two plants must be close for pollination purposes.
- See the chart to the right for ideas on how to plant the seedlings to get the highest yields.
Transplanting and Growing Seedless Watermelon
Follow these simple steps for a bumper crop of juicy, sweet seedless watermelons:
- Transplant the seedlings after the last frost date for your area.
- Place seedlings about four feet apart in rich healthy soil. If you don’t want weed, lay down a layer of black plastic before planting to kill the weeds.
- Water every day until the fruit appears, and then water only when the soil is dry.
- Fertilize with a 5-10-10 mixture as needed.
- Handle the fruit as little as possible during the growing season or the flesh will be bland and tasteless. The fruit is ripe when the rind resists the pressure of a fingernail.
Growing Watermelons for yourself is a lot easier than you think. Whether you want Early season, Main season, or Seedless Watermelons. Make sure you keep your Watermelons growing healthy using the right amount of watering, protecting disease and pests, and the addition of the right amount of nutrients at the proper time in their growth cycle.
Unlimited Watermelon for next summer mmmm…what a great thought!
Jim Galloway Author/Editor
Southern Living Magazine–Why Southerner put salt on Watermelon
Better Homes & Gardens–The No-Fail Method to Growing Watermelon for a Summer Treat