Sweet Siberian Watermelon

20 Seeds

Sweet Siberian is an old Russian heirloom watermelon variety introduced commercially in the late 19th/early 20th century. It produces elongated, light-green fruits with sweet, juicy yellow to apricot-orange flesh and small dark seeds. Different historical selections can vary somewhat in fruit size and flesh color.

The variety is generally described as producing fruits around 8–10 lb (3.6–4.5 kg), although historical trials recorded larger fruits under favorable conditions. It is an open-pollinated, vigorous vining watermelon and is considered relatively early, with maturity commonly around 80–85 days under suitable growing conditions.

🌱 Best Planting Time

• Gulf region: February–April and September–October
• Kuwait: March–April and September–October
• Best Kuwait periods: March–April for spring production and September–October for an autumn crop.
• Plant only after the soil has become warm.
• Avoid the coldest winter conditions and the peak of extreme Gulf summer heat.

Watermelon is a warm-season crop and should be planted when soil temperatures are at least around 21°C.

🌿 How to Plant the Seeds

1. Choose a location with full sun and excellent drainage.
2. Prepare loose, fertile soil and mix in mature compost.
3. Make small planting mounds or raised planting areas.
4. Sow 2–4 seeds about 1–2.5 cm deep.
5. Water gently after sowing.
6. Keep the soil evenly moist until the seedlings emerge.
7. Once the seedlings have developed their first true leaves, keep the strongest plants and remove the weaker ones.
8. Allow approximately 90–180 cm between plants, depending on how much space is available for the vines.
9. Leave approximately 2–2.5 m between rows where possible.
10. Mulch after the soil has warmed to help conserve moisture and suppress weeds.

Watermelon is commonly direct-sown about 2.5 cm deep, with wider spacing required because the vines spread extensively.

🌡️ Germination

• Suitable soil temperature: approximately 21–30°C
• Days to germination: about 4–10 days
• Warm soil produces faster and more uniform emergence.
• Keep the seedbed moist but not saturated.
• Provide strong light immediately after emergence.

Sweet Siberian is reported to germinate in approximately 4–10 days, while general watermelon guidance indicates rapid emergence when soil temperatures are warm.

🌱 Transplanting

Sweet Siberian can be started in individual pots and transplanted while young.

• Start seeds approximately 3–4 weeks before outdoor planting if an early crop is desired.
• Use individual biodegradable or larger pots to minimize root disturbance.
• Transplant when seedlings have 1–2 true leaves and the outdoor soil is warm.
• Harden plants gradually before exposing them to strong Gulf sunlight.
• Handle the root ball carefully because watermelon roots do not respond well to unnecessary disturbance.

Direct sowing is preferable when outdoor conditions are already warm.

☀️ Sunlight

• Provide full sun.
• Aim for at least 6–8 hours of direct sunlight each day.
• Strong sunlight supports vigorous vines and good fruit development.
• In the Gulf, protect very young seedlings from exceptionally intense afternoon heat.
• Maintain good air circulation around the vines.

Sweet Siberian is a full-sun, warm-season watermelon.

💧 Watering

• Keep the soil evenly moist during germination and early growth.
• Water deeply rather than giving frequent shallow watering.
• Provide reliable moisture during flowering and fruit enlargement.
• Avoid severe water stress while fruits are developing.
• Do not keep the soil continuously saturated.
• As the fruit approaches maturity, avoid excessive irrigation because overwatering can contribute to fruit splitting and dilute fruit quality.

Watermelons have extensive roots but still require consistent water during fruit development; deep irrigation is preferred.

🌱 Soil

Use:

• Loose, fertile, well-draining soil
• Sandy loam or light loam
• Mature compost or well-decomposed organic matter
• Perlite, pumice or coarse material for containers where needed

Watermelon grows well in fertile, well-drained soils. A soil pH around 6.0–7.0 is suitable for good growth.

Avoid heavy soil that remains wet around the roots after irrigation.

🌿 Fertilizing

• Add mature compost before planting.
• Use a balanced fertilizer during early vine development.
• Once vines begin actively growing, provide additional nutrition if the soil is poor.
• During flowering and fruit development, maintain balanced nutrition with adequate potassium.
• Avoid excessive nitrogen, which can produce excessive vine and leaf growth while reducing fruit production.

🌸 Flowering & Fruit Development

Sweet Siberian produces separate male and female flowers on the same plant. Bees and other pollinating insects are important for successful fruit set.

The fruits are typically:

• Elongated
• Light green-skinned
• Approximately 3.5–4.5 kg in many seed descriptions
• Sweet and juicy
• Yellow to apricot-orange fleshed
• Small-seeded

Some historical sources describe considerable variation in fruit size and even flesh color, so the exact appearance can depend on the particular seed line.

🍉 Harvesting

Sweet Siberian generally matures in approximately 80–85 days, although actual harvest time can vary considerably with temperature, pollination, irrigation and growing conditions.

Useful maturity signs include:

• The tendril nearest the fruit becomes brown and dry.
• The ground spot changes toward yellow or creamy yellow.
• The rind loses some of its glossy appearance.
• The fruit reaches its expected mature size.
• The fruit may produce a deeper, more hollow sound when tapped.

Use several indicators together rather than relying on only one sign.

🪴 Growing Sweet Siberian Watermelon in Containers

Sweet Siberian can be grown in a large container, but its vines require substantial space.

• Use a container of 50–60 L or larger per plant.
• Ensure excellent drainage.
• Allow the vines to trail over the ground or across a suitable growing area.
• Avoid overcrowding.
• Monitor moisture closely because containers dry quickly in Gulf heat.
• Place developing fruits on straw, a board or another dry surface to keep them away from continuously damp soil.

🐝 Pollination

Good pollination is essential for producing well-developed fruit.

• Encourage bees and other pollinating insects.
• Avoid insecticide applications while flowers are open whenever possible.
• If natural pollination is poor, hand-pollination can be performed by transferring pollen from a freshly opened male flower to a female flower.

🔥 Gulf Climate Tips

• Sweet Siberian is a warm-season watermelon and can perform well during the Gulf's warm growing periods.
• In Kuwait, March–April is a practical spring planting window.
• September–October can provide another growing opportunity as the extreme summer heat begins to decline.
• Avoid planting during the most intense summer heat.
• Protect young seedlings from extreme afternoon temperatures.
• Use mulch to conserve moisture and help moderate soil temperature.
• Maintain excellent drainage.
• Give the vines plenty of room to spread.
• Provide consistent irrigation during flowering and fruit development.
• Avoid excessive watering as the fruit approaches maturity.
• Good airflow helps reduce problems associated with excessive humidity.

🌱 Growing Tip: For the best results in Kuwait and the Gulf, plant Sweet Siberian Watermelon when the soil is warm, preferably during March–April or September–October. Give the vines full sun, plenty of space, deep consistent watering and fertile, well-drained soil. As the fruits approach maturity, avoid excessive irrigation to help maintain their characteristic sweet flavor.