Melon

There is nothing like refreshing melons on a hot summer’s day. Today there are so many types available, from cantaloupe and watermelon to unique muskmelons. The secret to a good melon crop in Oregon is lots of heat, and planting short season varieties. You can start directly from seed or transplants. Dwarf varieties can be grown in large containers.

Site Requirements

You should plan to plant melons in the hottest spot in your garden. They thrive in full sun, at least 7 hours of direct sun, and in rich, well‐drained soil. Prepare the planting area by mixing 2‐4” of composted manure and lime into the top 6‐10” of the soil. You can even cover planting area with black plastic to help retain heat.

Planting

Melons thrive in warm weather and are best planted outdoors June through the first week of July when soil temperatures are 65° or above. Space groups of seeds 3‐4’ apart in hills, or in raised beds spaced 5‐6’ apart. Be sure to mix an all‐purpose fertilizer into the bottom of each hole. Sow 2‐3 seeds 1⁄2” deep and cover seeds with a thin layer of soil. Once seeds have germinated, pinch off the weakest ones so you are left with the strongest one.

You can start seeds indoors in the last week of May, or three weeks before desired transplanting date. It is recommended to start seeds indoors in pots which can be planted in the ground directly, because melons do not like roots disturbance. When seedlings have their first true leaf, move them to a cold frame for a 4‐7 days. Water in freshly planted seedlings with a diluted liquid seaweed or B1.

Keep new beds well weeded and slightly moist. You can cover new plantings with floating row cover to prevent cucumber beetles and other insects. Remove row covers when plants begin to flower. Plastic or organic mulches can help heat the soil and retain moisture. It also helps to trellis your melons to save space and prevent diseases.

Water Requirements

How much water your plants will require depends on the soil and weather. Melons want consistent, moderate watering. If the top four inches of the soil is dry or the plants wilt early in the day, water slowly and deeply. Mulch with a 1⁄2” layer of compost to retain moisture and prevent over heating. Drip irrigation is the best way to provide even moisture and avoid disease issues.

Fertilizing

Melons are heavy feeders. Fertilize with an all purpose fertilizer or compost when vines are 12‐18” long. Apply a liquid fertilizer or foliar spray when the first fruits form.

Tips

In midsummer, pinch the growing ends off all shoots to help concentrate energy into the fruits. Also remove baby melons at the same time. Smaller fruited varieties will produce 4‐6 melons per vine, and lager fruited varieties (such as watermelons) produce about 2‐3 melons per vine. Lift melon vines off the ground with a trellis or “A” frame structure. This provides better air circulation for optimum plant health, and keeps fruits from rotting on the soil.

Harvesting and Storage

Every variety has different cues for ripeness. Muskmelon and cantaloupe develop a crack around the stem and easily “slip” from the vine when they are ripe.

Watermelons ripen about 35 days from when the first female flowers fully open. Also, the tendril on the fruit stem dries up, the color around the stem becomes dull, the spot resting on the soil turns from white to yellow or cream, and the fruit gives a hollow sound when thumped. Honeydew and charentais must be cut from the vine.

Ripe honeydew and relatives will lighten in skin color, the hairs on the skin will fall off easily and the end of the fruit will have a sweet scent. Melons can store for a month if kept refrigerated.

Pests and Diseases

Good gardening practices such as crop rotation, drip irrigation, proper planting time, floating row covers, and removal of entire plants when harvest is done all help prevent many pest and disease challenges.

• Flowers may not form fruit for a variety of reasons. Most cucumbers have separate male and female flowers. Often the first flush of flowers is only males. Other times you may have female flowers with tiny fruit that never develop and fall off. In this case lack of pollination is the issue. Cool cloudy weather can also deter pollinating insects from visiting your plants. Hand pollinate with a paint brush to help fruit set. A few varieties require a second, different variety for pollination. Orient Express and Cool Breeze are two varieties that require a pollinator. 95 days to maturity.
• Anthracnose appears as yellow and brown spots on leaves coupled with dark streaks on stems. It is a fungal disease that can be controlled with serenade and copper sprays. 95 days to maturity.
• Angular leaf spot appears as geometric yellow and/or brown leaf spots which eventually leave holes. It is a bacteria spread by splashing rain. Remove infected areas, avoid overhead irrigation and use plastic mulches to prevent infection. 95 days to maturity.
• Bacterial Wilt is a virus which causes leaves or the whole plant to wilt. Cut stems will exude a thick ooze. There is no cure, but using floating row covers helps prevent cucumber beetles which transmit the virus. 95 days to maturity.
• Cucumber Mosaic virus appears as yellow, mottled, curling leaves. As with other viral diseases there is no cure, and infected plants should be removed and destroyed. 95 days to maturity.
• Downy Mildew appears as splotches of angular yellow or brown spots that are purplish on the underside. Infected leaves should be removed. Spread of the infection may be controlled with Serenade. *Powdery Mildew will occur on all cucurbit crops at some point in the season. It may first appear as powdery white spots on leaves and stems or coat entire leaves. The fungus spreads in warm, dry weather. Pick off infected areas and spray with copper or serenade to prevent the spread of the fungus. 95 days to maturity.
• Cucumber beetles may chew seedlings or leave a lacy pattern in leaves of larger plants. They transmit bacterial wilt. Use floating row covers crop until flowering begins. Beneficial nematodes can kill the larvae, lacewings and ladybugs will eat eggs, and rotenone and pyrethrin can help control populations. 95 days to maturity.
• Melon aphids cause leaves to curl, distort and turn yellow. Usually white aphid skeletons are under or near colonies of apple green bugs which are visible on the growing tips and underside of leaves. There are numerous control methods to control aphids such as ladybugs and insecticidal soap. 95 days to maturity.