How to Grow Watermelon and Other Melons from Seed
When you think of melons, you probably think of summer. It's hard to beat the simple pleasure of eating a sweet, juicy slice of chilled honeydew or watermelon on a hot day. Well, the world of melons has far more to offer than that one nostalgia-inducing delight, and what a delicious world it is!
There's a wide variety to choose from, ranging in size from slightly larger than a softball to hefty 50-pound beauties, and they come in a range of colors, both inside and out. Melons are extremely versatile, proving wonderful freshly picked or cooled in the refrigerator, and they make a healthy dessert or snack as well as an ingredient in salads, salsas, entrees, side dishes, and drinks!
Choosing a Variety: Watermelon, Cantaloupe, Honeydew
When choosing which variety of melons to grow, you will want to take into consideration the size of your growing area. Melons are vining plants and tend to require a lot of space, so be sure to grow only varieties you know you'll enjoy eating. Some gardeners have started growing melons vertically (on trellises, etc.) in order to conserve space. If you want to try this method, research which ones would be most appropriate.
Since melons come in such a wide variety of sizes, colors, and flavors, these characteristics will also play a role in what types you decide to plant in your garden.
When to Start Melon Seeds
If you live in an area with a long growing season, melons do best if the seeds are sown outdoors when the soil is warm and all danger of frost has passed. You can sow them indoors 3 to 4 weeks before night temperatures remain above 55°F.
How to Start Melon Seeds
Whether you are planting indoors or out, sow your melons at a depth of 4 times the size of the seeds. If you're planting inside, sow them in individual pots, as they don't like being transplanted. Seedless watermelons should be started indoors.
When sowing outdoors, make a small hill of fertile, well-drained soil and plant 3 to 5 seeds about 2 inches apart. Water well.
Expect your watermelons to germinate in 8 to 14 days. Other melons will germinate within 7 to 10 days.
Transplanting Melon Seedlings
You need to harden off your young melon plants for at least a week before planting them out. Set them outdoors in a lightly shaded area for an hour or two. The next day, give them a longer visit outside until they remain outdoors overnight, still in their pots. Naturally, if a cold spell hits, bring them indoors again to wait for the temperature to rise.
Watermelons:
You will want to transplant your watermelon seedlings when they have at least two sets of true leaves. Be very careful with the roots—they resent being disturbed. Space them about 2 feet apart in rows that are 6 to 8 feet apart, or plant them in threes on hills. Space the hills 6 to 8 feet apart. Plant in full sun, in a rich, sandy, well-drained soil. You will need to water well while the plants are growing, but once the fruit is ripening, keep the soil on the drier side, as this will improve the sweetness and flavor.
Other Melons:
Fertilize before you plant and then again every 4 weeks. You will want to transplant your melon seedlings when they have at least two sets of true leaves. Space them about 18 inches apart in rows that are about 4 feet apart, or plant them in threes on hills. Space the hills 4 to 6 feet apart. Plant in full sun, in a rich, sandy, well-drained soil. You will need to water well while the plants are growing, but once the fruit is ripening, keep the soil on the drier side, as this will improve the sweetness and flavor.
Once your melons have been transplanted, if cold weather should threaten, you can make a mini-greenhouse out of a one-gallon, plastic milk jug. Just cut the bottom off and set it over the plant, pushing it about ½ inch into the ground. During the day, it can be vented by removing the cap.
Special Considerations
Be sure not to start your melons too early.
Watermelon:
- Large watermelon seedlings do not transplant well.
- Watermelons need a long growing season with relatively high temperatures—between 70 and 80°F during the day and between 65 and 70°F at night.
- Don't set out Watermelon plants until all danger of frost has passed, as they are very sensitive to freezing temperatures.
Growing Tips for Melons
- Some gardeners, particularly those living in cold-winter climates, choose to plant their melons through black plastic mulch, as it absorbs heat, warms the soil early, helps retain moisture, makes harvesting easier and cleaner, and aids in keeping away weeds, pests, and diseases.
- Melons are both thirsty and hungry, so be prepared to water well and provide plenty of nutrients. Give them a minimum of 1 inch of water a week—2 inches is better. Water in the morning, preferably with a drip irrigation system.
- About once a month, add several inches of compost to all root areas.
- Watermelons do well in humid or semi-arid areas, but foliar diseases are less likely to occur in drier climates. They also prefer sandy loam soil, but clay soils can be quite productive if raised planting rows are mulched with black plastic film.
- Female flowers are the only ones that develop melons, so don't become upset if the first flowers you see are not setting fruit. The earliest flowers are male (pollen bearing), and they can't produce fruit.
- Make every effort to protect the bees during the flowering period, as honeybees are the most effective pollinators of melons.
- If you don't have a lot of space to grow melons, there are some varieties that can be grown in containers or up trellises. You will have to make sure you have a container that is large enough to handle the plants and pick a melon that isn't going to get so large that it will be too much, for either a container or a trellis.
- Harvesting your melons at the peak of perfection takes some experience. For watermelons, check the ground spot—it will change from pale green or white to cream or yellow, and the tendrils near the stem will become dry and brown. You will also find the skin to be rough to the touch and resistant to penetration by your thumbnail.
- Other melons tend to become fragrant when they're ripe. Sniff the skin, and if it smells like the flavor of that particular melon, it is probably ready to be picked. Also, with many melons, the stem will easily separate from the fruit when ripe.
- You can tell when your cantaloupes are ripe by looking at the rind—it will change from green to tan-yellow between the veins.
- Honeydew and other winter melons will turn completely white or yellow when they're ripe, and the blossom end of the fruit will be slightly soft to the touch.
- Watermelon vines hate to be disturbed. Their leaves orient themselves to the sun, and if you move the vine and disturb the orientation, it can actually set the plant's development (and fruiting) back a bit while the energy goes slowly re-orienting the leaves to the sun.
Pests and Problems to Watch For
- Cucumber beetles will sometimes attack watermelon plants. These can be controlled with the application of an insecticide, or the use of row covers early in the season before the beetles have a chance to get to the crop. You can leave the row covers in place until the plants begin to bloom, at which point they need to be removed so pollinating insects can reach your plants.
- Fungus diseases, including Alternaria leaf spot, powdery mildew, anthracnose, and downy mildew are also possible.
- Prevention is the key to disease and pest management. Healthy plants are far less likely to attract problems than weak ones. Plant in rich, well-drained soil in full sun with plenty of air circulation, and you'll get healthy plants that bear lots of fruit.
- Walk around your garden several times a week and inspect your plants. Immediately remove any that have signs of disease.
- Clean up well after the season has passed to prevent anything carrying over to the next year.
- Rotate your crops to keep possible diseases from transmitting season to season.
- Contact your local Extension Office for specific disease and pest prevention and management in your area.
