Melon: Sow and Grow Guide
Is a melon by any other name still a melon? Yes! What many of us call cantaloupes are really muskmelons. True cantaloupes have a smooth, hard shell, and are most commonly grown in the Mediterranean region.
Muskmelons’ rind can be described as having a raised, net-like texture, like what you see at the grocery store being sold as cantaloupes. Honeydew melons are different from muskmelons in that the skin is smooth, the flesh is green, and they have a distinctively different flavor and are often sweeter.
If you were wondering how to grow melons from seed, you’ve come to the right place!
General Sowing
When to Sow Outside: RECOMMENDED. 1 to 2 weeks after your average last frost date, and when soil temperature is 70°–90°F, typically in mounds or they can also be grown on a trellis.
When to Start Inside: Recommended for short-season areas. 2 to 4 weeks before your average last frost date. Sow in biodegradable pots that can be directly planted in the ground; roots are sensitive to disturbance.
Indoor Sowing
If you have a shorter growing season, you may consider starting your melon seeds indoors. Use a lightweight seed starting mix/medium (sterile and lighter than potting mix), and sow melon seeds 1/2″ deep. Sow 2–3 seeds per pot, thinning to the strongest plant once leaves appear (clip extra plants at the soil level using scissors).
The strongest plant may not be the tallest; look for thick, strong stems and deep color. By thinning early, seedlings won’t stretch to compete with other seedlings for light. Read more indoor sowing tips.
Containers
Sow in 3″–4″ biodegradable pots that can be planted directly into the ground, minimizing root disturbance. Biodegradable paper pots are the ideal size, easy to label, and convenient for sharing plants with friends. Melon roots are sensitive to transplanting, which is why direct sowing is our recommendation.
Transplanting
Harden off seedlings 2½ to 3 weeks after seedlings emerge. Hardening off is the 7 to 10-day process of introducing pampered seedlings to the intense outdoor sun and temperature swings. Read detailed hardening off instructions here
Transplant to an area of full sun (6 or more hours a day), when soil temperature is at least 60°F, often about 2 weeks after your last frost but double-check the weather forecast to be sure. Transplant on a cloudy day or in the evening to reduce stress or use row cover to buffer both sunlight and temperature swings while seedlings adjust to their new home.
Outdoor Sowing
Sowing Preparation and Spacing
Melons grow best in light, well-drained soil that is rich in organic matter. They are heavy feeders, so adding organic matter like compost and manure to the soil before sowing can not only add nutrients but help drainage and water retention.
Melon seeds need warm soil to germinate and grow well. Covering your growing area with plastic prior to sowing can help heat up soil earlier in the spring. Mounds should be 4’–6′ apart, sowing 2–3 melon seeds per mound. If you are growing them on a trellis, you can reduce the spacing to 2’–3′ apart.
Thinning
Thin to one plant per mound or trellis spacing once plants have 2–3 leaves.
Water
Melons need a lot of water. Water deeply; keep evenly moist, but not soggy. Allow only the top 1″–2″ of soil to dry between waterings. Once fruits start to form, reduce water to prevent splitting.
Fertilization
Melons are heavy feeders. A soil test will give you the best information about any improvements your soil may need. Generally, melons need balanced fertilization (equal parts nitrogen, phosphorus, and potassium) to start growing large, healthy plants. Once flowers form, add higher levels of phosphorus and potassium to contribute to flower and fruit formation.
Weeding
Keep plants well weeded but cultivate lightly; roots are shallow. As the vines grow, the leaves will shade the soil and help stifle weed seeds from germinating.
Special care
Sowing in raised mounds will also help warm the soil in spring and help with drainage. Mulching with straw or compost will help to retain moisture and keep developing fruits off the soil, preventing fruit rot. If you are growing melons on a trellis support fruits with a fabric sling made of material with some stretch like strips of t-shirt material or nylons.
The key to a sweet melon is lots of sugar, which is produced by the leaves, so healthy leaves is a sign of good quality fruit. Proper spacing, thinning, and trellising increase airflow, which helps protect leaves from fungal diseases.
Pollination
Melons have both female and male flowers on the same plant and the pollen from the male flowers need to be transferred to the female flower in order for fruit to form. Bees are great pollinators for melons, but if they are scarce you can hand-pollinate. Learn how to hand-pollinate melons.
Harvesting
The last few days of ripening on the vine put a lot of sugar into the melon, so allowing melons to vine-ripen will give the best flavor. Consult the inside of your seed packet for signs of ripeness specific to that cultivar.
Storage
Muskmelons, Galia (‘Ha Ogen’), and Cantaloupe (‘Charentais’) melons continue to develop flavor for a couple days after harvest and store for about 2 weeks in the refrigerator.
Honeydew, Persian, Papaya Dew, and Canary melons continue to develop flavor for a couple of days after harvest and retain their flavor for 2 to 3 weeks when stored at 45°–50°F. Storage below 40°F can cause “chilling damage”; do not refrigerate.
Cut melons should be stored in the refrigerator but only store up to about a week before they start losing flavor and texture quality.
Common Pests and Diseases
Powdery Mildew looks like a white powder on leaves and thrives in hot weather with high relative humidity and cool nights. Reduce chances of this disease by watering only in the morning and during the day. Keep leaves dry; do not water plants overhead.
Provide good air circulation by proper plant spacing. Do not compost diseased plants; spores may over-winter and re-infect crops the following season.
Organic fungicides like those that are sulfur, copper, or neem based can be helpful in preventing the spread of powdery mildew, but the trick is applying a solution as soon as possible; some even say to do it pre-emptively.
Home Remedies
A Horticultural oil and baking soda combination has been found to prevent powdery mildew. Mix 1 tbsp. of baking soda and the amount of horticultural oil recommended by the label in 1 gallon of water, and spray plant thoroughly weekly.
Milk Spray: Dilute milk to 20%–50% in water and add a couple drops of natural soap to help the spray stick to leaves, rather than rolling off. Apply weekly, spraying plants thoroughly for good coverage.