Melons

Melons thrive in fertile, fast-draining soil fortified with organic matter that holds ample moisture during long, hot summer months. In Sonoma County, not all micro-climates support melon growth. Cool, foggy conditions near the coast and somewhat inland rarely yield satisfying crops, although short-season varieties protected with row covers can be tried.

Melon Basics

Several closely related melons of the same species but of different varieties are treated similarly in the garden. All are available in named cultivars, each with slightly different characteristics.
Lightly ribbed European cantaloupes have greenish gray, often smooth skin with orange flesh.
North American muskmelon develop reticulated (netted) tan skin also with orange flesh.
Honeydew differs in appearance with light-colored skin, green flesh, and sweeter taste.
Casaba, crenshaw, Charentais, Crane (developed in Sonoma County) and others have their own distinctive appearance and flavor, sweet with yellow to orange flesh.
Bees are required for transferring pollen from male to female flowers on all melon vines.

Soil Preparation

Amend soil with several inches of compost to provide fertility and aeration, especially in clay where warmth is slower to penetrate. Spread amendments throughout the bed to accommodate rambling roots.
Dig in a slow-release fertilizer in a wide circle about 12 in. away from planting site for expanding roots, following directions on product label. Over-fertilizing will damage roots.
Spread black or clear plastic mulch over smooth, weed-free soil about 3 weeks in advance of planting to raise soil temperature in microclimates where soil is slow to warm.

Planting

Start several different varieties from seed if you plan to grow different kinds of melons rather than purchasing only one type in a single 6-pack. Numerous varieties are available by mail-order.
Sow seeds directly when soil has warmed above 70 degrees about 2-3 weeks after danger of frost, or start indoors in a warm mix and transplant in 2-3 weeks when soil temperature reaches 70-75-degrees. Allow 7-10 days for germination.
Plant in hills (clusters) of 6-8 seeds 4-6 ft. apart; thin to the strongest 2-3 seedlings in each hill.
Set out transplants before the taproot circles in the pot and take care not to disturb roots as you plant. Set 2-3 transplants in each hill. Be sure to harden off plants before setting them out.

Growing Conditions

Use spun fabric row covers to hold in warmth, enhance yield, and promote early harvest.
Keep soil lightly moist to a depth of 6 in. during flowering and as fruit develops, but stop watering a week before harvesting. Too much water as fruit ripens can reduce sweetness.
Place a wood shingle, tile, or protective mulch material under fruits to lift them above the soil and prevent rot or insect damage.
Economize on space by training vines on a stout trellis or wire cage. Support fruits in a sling to keep vines from breaking. Use raised beds that allow vines to tumble over the sides.
Provide shade for light-skinned crenshaw, honeydew, and some cantaloupe melons when sunlight is intense.

Harvesting

Consult seed packets for number of days to maturity, usually 35-45 days after flowering, 80-100 days from seeding, depending on variety and soil and air temperatures.
Count on a maximum of four melons per vine from most varieties.
Determine when a melon is ripe with a trial and error approach. They should be firm but have a very slight softness against the base of the stem and a slight crack at the point of attachment.
Watch for an increase in fragrance, netting on the skin surface to become coarse and rough, tendrils on the stem to dry and turn brown, a color change from gray-green to tan on some varieties. Honeydew, crenshaw, and casaba melons turn a waxy yellow.
Expect melons to soften and become juicier after picking, but not ripen further or get sweeter.

Avoid Problems

Plan for success with proper site selection, soil preparation, timely planting, and effective watering—all are important for plant health and pest reduction.
Pollinate by hand when no bees are present to transfer heavy pollen from male to female flowers. Early blooming flowers are male; female flowers have a miniature fruit at their base.
Transfer pollen early in the day, targeting newly opened flowers.

Additional Information

February 2022