Few things say summer quite like biting into a sweet, juicy melon. Cantaloupes, honeydew and watermelons are all a delight to grow when they have the sun, heat and fertility that they need. Their spreading and climbing vines make the garden visually appealing too. If you want to grow melons in your garden, here’s what you need to know.
You can also download my How Do I Grow Melons? one-sheet and keep the free resource handy for your reference.
A melon is a wonderful treat alone but can also go into fruit salad. Cantaloupe can be paired with cottage cheese for breakfast or with ice cream for dessert, and can even be turned into sorbet or roasted. Watermelon with cucumbers and mint is a summertime favorite salad, and watermelon makes a great base for a smoothie as well. Honeydew works as a sorbet or smoothie ingredient as well, and can also be made into salsa. And once you grow melons, you’ll continue to find new ways to prepare them.
When and How to Start Melons
Melons can be started from seed indoors a month before the last frost date. Plant three seeds per cell or per pot in sterile-seed starting mix, a quarter-inch deep, and place the containers over a seedling heat mat set to 85°F. The seeds should germinate in three to four days at that temperature.
Keep the seedlings under grow lights so the plants don’t reach for the light. In low-light conditions, plants will become leggy and weak. Running a fan over the seedlings is also helpful as it prevents damping-off disease, which can be fatal to seedlings before they grow their first true leaves.
A week to 10 days before you plan to plant out, begin to harden off the seedlings. Put the seedlings out in the sun for a short time on the first day — a half-hour — and gradually increase the time spent outdoors each day. By the end, the plants will be ready to receive a whole day’s worth of sun.
In warmer climates, seeds can be direct sown rather than started indoors. In cooler climates with a shorter growing season, melons need that head start indoors to give them adequate time to produce fruit.
Where and How to Plant Melons
The key to growing a successful crop of melons is heat. Don’t even start planting your melons until soil temperatures are above 70 degrees. They also like well-amended and very nutrient-rich soil. Working a generous amount of compost and composted manure into the soil before planting will set your melons up for success.
Many gardeners place sheets of black plastic down over the planting area to hasten the warming process and to protect the plant’s foliage and vines. The plastic mulch is also an excellent way to eliminate weeds from growing up among the vines, which is especially important considering you won’t have an easy way to get to weeds once the vines start to take off and spread all over.
When I grow melons over plastic, I always run a soaker hose under the plastic first. It makes for easy watering, and I know the plants are getting the water they need while keeping the foliage dry.
Melon vines need plenty of room to roam. Plant seeds or seedlings so you end up with two or three plants on mounds with room to spread out in all directions, or space them in rows, one plant every foot with about 6 feet between rows.
You can even plant melons at the base of a large trellis, such as a livestock panel arbor, and train them to grow up. Just gently tie the vines using soft, flexible fabric-like strips of old stockings. They’re also the perfect sling for holding the developing melons to ensure they remain attached to the stem until harvest.
If you’re growing on the ground, keeping the fruit off the ground is important to avoid rot as well as pests. I use an upturned flower pot saucer, but just about anything you can rest a melon on to raise it off the ground should work.
Types and Varieties of Melons
Generally speaking, “melon” refers to plants belonging to the genus Cucumis with sweet and fleshy fruit, but then there is also watermelon, which is in the genus Citrullus. Each type of melon also has many different cultivars that are suited to different growing conditions and have different colors, shapes and flavors — so there is a melon that’s right for you.
Athena is a cantaloupe that’s known for its resistance to Fusarium wilt, powdery mildew and cracking, and its long shelf life. Athena matures in 79 days.
Halona is a deep-ribbed muskmelon with round fruit and bright orange flesh. It is fast to maturity: Just 73 days.
Milan is a juicy Italian cantaloupe with oval-shaped fruit and green lines down the ribbing. Each fruit is approximately 5 pounds. It has resistance to Fusarium and to powdery mildew.
Sugar Cube is a very sweet cantaloupe with round 2-pound fruit that lack ribbing but have consistent netting. The plants are resistant to a wide variety of diseases. Sugar Cube can be grown in both northern and southern regions and matures in 80 days.
Honeycomb is a honeydew with smooth, cream-colored skin on globe-shaped fruit. It can be transplanted outdoors once soil has reached 60°. Each fruit is 5 ½ pounds with crisp, medium-firm pale green flesh. The plants mature in 78 days.
Orange SilverWave is an exotic melon that is an All-America Selections winner. The vigorous vines grow up to six fruit each. The 5-inch oval fruit have sweet orange flesh, while the skin is white with flecks of green. It matures in 75 days.
Moonstruck is a Japanese honeydew with smooth white skin and tender white flesh. The globe-shaped fruit reach 7 inches across and 5 to 6 pounds each. It’s best suited in a growing area with a long season. It matures in 75 days.
New Queen is an early-maturing watermelon with bright orange flesh that’s crisp and juicy. The globe-shaped fruit grow to be 5 to 6 pounds each with skin that’s light green with dark green stripes. New Queen matures in 80 days.
Moon & Stars looks like a typical pink-fleshed watermelon when you cut into it, but on the outside, the skin is deep green with a big yellow dot (the moon) and lots of little yellow dots (the stars). Each fruit can be up to 40 pounds. It matures in 100 days.
Sangria is a traditional oval-shaped watermelon that is green with lighter green stripes, and deep pink-to-red flesh inside that’s high in sugar. Each fruit can top 20 pounds. Sangria matures in 87 days.
As mentioned above, soaker hoses work very well when growing melons, especially underneath black plastic mulch. If you are not using black plastic mulch to suppress weeds and increase the soil temperature, you can use a three-inch layer of organic mulch such as arborist’s wood chips or shredded leaves to keep weeds down and retain water.
Melons require between 1 and 2 inches of water a week. If it hasn’t rained that much, make up the difference with supplementing watering. If you are not using soaker hoses, then be extra careful as you apply water to avoid getting the plant foliage wet. Overhead watering that splashes soil around and results in wet leaves makes it easy for diseases to spread. It’s best to gently apply water at the base of plants.
Melons planted in soil that’s been enriched with composted manure will benefit from all that nitrogen. Nitrogen encourages the growth of vines. When the plants are further along and are beginning to flower, they will need fertilizer that is higher in phosphorus and potassium than nitrogen in order to set fruit. Look for an organic fertilizer with an NPK (nitrogen, phosphorus, potassium) ratio that has a lower first number than the second and third numbers. Follow the manufacturer’s instructions when applying: More does not equal better and can instead be detrimental.
Melon Pests & Diseases
Avoiding overhead watering will cut down on melon diseases, but disease issues may continue to arise. Melons also have a few pests that love them too. Melon aphids colonize quickly so be vigilant in inspecting your plants, especially under the leaves and on the vines. Insecticidal soap is a good treatment but you have to make contact with the aphids for control.
Powdery mildew is a fungal disease that sometimes affects tomato plants. Proper spacing of plants to provide air circulation can reduce the chances of powdery mildew becoming an issue. A solution of baking soda or diluted milk can slow the spread or be used as a preventative measure. (Read my comprehensive guide to powdery mildew control for more.)
Melon aphids are sucking insects that are vectors for plant diseases. They colonize quickly, so be vigilant in inspecting your plants, especially under the leaves and on the vines. As the aphids feed on plant leaves, they excrete honeydew, which attracts ants and other insects. They are easily controlled by knocking them off plants with a sharp stream of water or by applying insecticidal soap.
Cucumber beetles, which have both spotted and striped species, are common melon pests that chew holes in leaves and pass a pathogen that causes bacterial wilt that can kill your plant in a matter of days. You need to stay ahead of the problem to keep your plants viable until harvest. Inspect under plant leaves for eggs, which should be scraped off, and hand-pick any adult beetles you find. If a cucumber beetle problem arose one year, chances are it will happen again the following year. Practice crop rotation so the cucumber beetle population does not build up in your garden.
Cutworms wrap themselves around the stems of young plants and chow down. They are actually moth larvae and can be controlled with paper collars around the stems.
Flea beetles are small black or bronze jumping leaf beetles, just an eighth of an inch long. These chewing insects can be kept off young melon vines with floating row cover. Another strategy is to plant a trap crop of radishes, which flea beetles prefer over melons. By summer, melon vines are established enough to shrug off flea beetle damage, and their presence then should not raise concerns.
Root-knot nematodes form galls in melon roots, where they steal nutrients. If you go heavy on water and fertilizer, an affected melon plant may still be able to produce. It’s said that interplanting French marigolds in the garden will repel nematodes. However, if you know nematodes are present, plant resistant varieties or practice crop rotation by refraining from planting melons in that garden bed for three or four years, so the nematode population subsides.
Whiteflies are similar to aphids in that they suck sap and cover plants in honeydew — and are vectors for diseases. They are naturally controlled by wasps, but melon vines can also be treated with insecticidal soap.
For the sweetest melons, consider reducing the number of melons per vine by selecting the best-looking and sacrificing the others. This way, the remaining melon will have all of that vine’s resources for ripening and sweetening, more so than if those resources were being allocated to multiple fruits.
Cantaloupes and other muskmelons are ready to harvest when the rind changes color from a gray-green to a dull yellow. The melon should still be firm, but some gentle pressure from your thumb against the stem will separate a ripe fruit from the plant. If that doesn’t happen, wait and try again in a couple of days.
Honeydew is ready to be picked when the skin turns completely white or yellow — depending on the variety. A ripe honeydew should be removed from the vine with garden shears. Do not attempt to pull it off the vine, as you would with a cantaloupe.
To tell when a watermelon is ready to be picked, examine the tendrils closest to where the stem meets the fruit. When the tendrils turn brown and dry, the watermelon is ready to be picked — with shears. A ripe watermelon will sound hollow when you knock on it.
You can harvest a melon before it is ripe and keep it stored at room temperature. Once ripe, enjoy, or keep it refrigerated and serve it within a few days.
What are your secrets to successfully growing melons? Let us know in the comments below.
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Links & Resources
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joegardener Online Gardening Academy™: Three popular courses on gardening fundamentals; managing pests, diseases & weeds; and seed starting!
joegardener Online Gardening Academy Beginning Gardener Fundamentals: Essential principles to know to create a thriving garden.
joegardener Online Gardening Academy Growing Epic Tomatoes: Tomato expert Craig LeHoullier joins me in leading this course on how to grow healthier, productive tomato plants and how to overcome tomato-growing challenges.
joegardener Online Gardening Academy Perfect Soil Recipe Master Class: Learn how to create the perfect soil environment for thriving plants.
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