Citron (Citrullus lanatus var. citroides)

Overview

Citrullus lanatus var. citroides, commonly known as Citron, presents gardeners with a vigorous annual vine related to modern sweet watermelons. While the primary appeal isn’t raw consumption due to its typically bitter, hard white flesh, the resulting fruit of the Citron melon is highly valued for preserving and pickling applications. This plant offers a sprawling presence in the garden, known for its pinnately dissected leaves and a prodigious yield of round to oval melons.

Successful cultivation of Citrullus lanatus var. Citroides requires patience and specific warmth, thriving best during long, hot summers. It demands fertile, organically rich soils and consistent moisture, although it exhibits an intolerance for overly wet or compacted ground conditions. Experienced gardeners appreciate the functional yield of this particular variety, often referred to as the preserving melon, distinct from the large sweet fruits of standard Citrullus lanatus.

Due to its rapid, widespread growth pattern, gardeners should allocate ample space for this annual vine to sprawl across the ground. Understanding the specific culinary uses of the Citron melon—namely preserves and jams—helps integrate Citrullus lanatus var. citroides effectively into the vegetable patch, offering a traditional crop distinct from modern favorites.

Fast Facts

• Plant Family: Cucurbitaceae
• Plant Type: Annual
• Hardiness Zones: USDA Zones 2-11
• Size at Maturity:
  • Height: 0.75-1.5 ft
  • Spread: 10-15 ft
• Bloom Time: July to August
• Bloom Description: Green
• Sun Exposure: Full sun
• Water Needs: Medium
• Maintenance Level: Medium

How to Grow

Starting Citrullus lanatus var. Citroides is best achieved by direct sowing seeds outdoors. Wait until the soil temperature consistently reaches 70 degrees F, generally coinciding with the last expected spring frost. Plant six seeds per hill, ensuring hills are set 4 to 6 feet apart, allowing adequate room for the wide-spreading vines. The best growing medium involves fertile, organically rich, well-drained loams.

Maintenance requires consistency, focusing primarily on moisture and weed management. Water regularly to keep the soil consistently moist, as this vine thrives in heat but suffers in drought or overly wet conditions. Spreading mulch around the base of the plants helps significantly in retaining soil moisture and suppressing competitive weeds, reducing maintenance effort.

This plant requires full sun exposure to maximize fruit production and minimize disease pressure. Pay attention to compacted soils, as they hinder vine vigor. While the fruit is the goal, gardeners should be aware that Citrullus lanatus var. citroides has naturalized in some warm regions of the U.S. and caution should be taken as vines may invade nearby citrus groves or surrounding areas.

Landscape Uses

As a vigorous annual vegetable, the Citron vine is typically reserved for dedicated kitchen garden spaces where its sprawling habit can be managed. Given its requirement for warm soil and full sun, it excels as a feature in large raised beds designated for heat-loving crops. While not traditionally used for ornamental borders, the dense foliage provides excellent ground cover in functional areas.

The primary intended landscape function centers on its productivity: growing enough melons for processing. Ripe fruits are excellent for preparing preserves, jams, or pickling projects, utilizing the hard white flesh. Furthermore, the seeds of the Citrullus lanatus var. Citroides are also reported to be edible, adding an extra layer of utility to this often overlooked cucurbit.

Gardeners planning rotational planting should ensure this vine does not follow other members of the Cucurbitaceae family too closely to help mitigate the buildup of soil-borne pests and diseases common to the family.

Standout Features

Flower Qualities

• Showy

Fruit Qualities

• Showy
• Edible

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. Its flesh ranges from bitter to unsweet, though it may hybridize with sweet watermelons yielding more palatable results. The Citron melon is noted for its pinnately dissected leaves and often prodigious crop of round to oval melons (to 10” long) which are perfect for preserves and pickling.

Tolerances

Potential Problems

Citrullus lanatus var. citroides is susceptible to several common cucurbit diseases, most notably fungal issues like anthracnose, downy mildew, and powdery mildew. Fusarium wilt and bacterial wilt can also manifest, requiring adherence to crop rotation practices. Prevention involves ensuring good airflow through proper spacing and avoiding overhead watering that keeps foliage wet.

Insect management is critical for a successful harvest of this Citron variety. Watch closely for cucumber beetles; if present, they should be removed immediately, ideally by hand, as they can rapidly spread disease. Other common pests to monitor include aphids, squash bugs, stink bugs, cutworms, the pickleworm, and squash vine borers. Mites can also become a factor in hot, dry weather.

Frequently Asked Questions

What hardiness zones is Citron suitable for?

The Citron (Citrullus lanatus var. citroides) is highly adaptable across a wide range, suitable for USDA Zones 2 through 11.

How large does Citron grow?

This annual vine typically achieves a height between 0.75 and 1.5 feet, but it spreads extensively, covering an area of 10 to 15 feet wide.

When does Citron bloom?

The pale green axillary flowers of Citrullus lanatus var. Citroides are typically visible from July through August.

What sun exposure does Citron need?

For optimal growth and fruit production, the Citron melon requires full sun exposure throughout the growing season.

Conclusion

The Citron (Citrullus lanatus var. citroides) provides gardeners with a unique, functional harvest, yielding melons perfect for preserves and pickling rather than fresh eating. By providing fertile soil, consistent moisture, and ample space for its robust spread during long, hot summers, you can successfully cultivate this distinctive annual vine. Before planting, verify your local last frost date to ensure soil temperatures are adequate for successful germination of Citrullus lanatus var. Citroides.

Companion Planting

When integrating the sprawling Citron into your vegetable garden, good companion plants share similar needs for rich soil, plentiful sun, and consistent water. Consider planting nitrogen-fixing companions nearby, such as beans or peas (though ensure they do not shade the low-growing vines). Taller, non-competing plants situated to the north can provide structure without obstructing necessary sunlight for the Citrullus lanatus var. citroides.

For pest management, aromatic herbs can offer a layer of natural defense. Planting strongly scented herbs like basil or nasturtiums near your melon hills may help confuse or deter common insect pests such as squash bugs or cucumber beetles that target Cucurbitaceae. This strategy supports a healthier growing environment for your preserving melons.

Seasonal Care Calendar

Spring preparation involves solarizing the soil if possible and ensuring the ground is deeply tilled and enriched with organic matter before sowing seeds after the last frost. Focus on soil temperature reaching 70°F for germination of Citrullus lanatus var. citroides.

Summer is the active growth and fruiting period, demanding the medium water needs be met consistently, especially during dry spells. Check frequently for signs of mildew or insect infestations, applying organic controls promptly to protect the yield of the Citron melons.

As autumn approaches in cooler zones, harden off plants or harvest fruits before the first hard frost halts all growth. Since this is an annual, cleanup involves removing all remaining vine matter post-harvest to reduce overwintering sites for pests and pathogens.