Culture
This annual vine can easily be grown from seed, but is uncommonly planted because the fruits are usually bitter and inedible in a raw state. It is best grown in fertile, organically rich, consistently moist, well-drained loams in full sun. Thrives in long hot summers. Intolerant of wet soils. Avoid compacted soils. Vines spread out over the ground. Seeds may be planted outdoors when soil temperatures have risen to 70 degrees F., typically right after last spring frost date. Plant six seeds per hill with hills spread about 4-6' apart. Spread mulch to help retain soil moisture and control weeds. Plants have naturalized in some southern parts of the U.S. (North Carolina to California) and are considered to be invasive in some areas. Vines will invade citrus groves.
Noteworthy Characteristics
Citrullus lanatus var. citroides, sometimes called citron melon or preserving melon, is a small round to oval watermelon with hard white flesh that is usually considered to be inedible raw. Flesh ranges from bitter to unsweet. Plants will hybridize in the wild with edible cultivated watermelons (Citrullus lanatus), sometimes resulting in citron melons with more palatable taste. Citron melon is noted for its pinnately dissected leaves and often prodigious crop of round to oval melons (to 10" long) which resemble small watermelons. Ripe melons may be used for preserves, jams or pickling. Seeds are edible. Pale green axillary flowers. By contrast, Citrullus lanatus, commonly known as watermelon, produces the large sweet watermelon fruits now grown round the globe.
Genus name comes from Citrus referring to the appearance of the fruit.
Specific epithet means woolly.
Problems
Anthracnose, blossom end rot, fusarium wilt, bacterial wilt, downy mildew and powdery mildew may appear. If present, cucumber beetles should be removed immediately by hand. Additional potential insect pests include aphids, squash bugs, stink bugs, cutworms, pickleworm and squash vine boreres. Watch for mites.
Uses
Melons may be harvested for use in preserves, jams or pickling. Seeds are edible.