Crimson Sweet watermelon in the garden with a wedge cut to show deep red flesh

How to Grow Crimson Sweet Watermelon From Seed

By Maxim Kaufman — Founder & CEO, Organo Republic

Updated July 2026

Crimson Sweet is the watermelon most people picture: a big, round melon with a pale green rind and dark stripes, packed with firm, sugary red flesh. Averaging 15 to 25 pounds, it ripens in about 85 days and rewards you with crisp, exceptionally sweet fruit and few seeds. It is also bred for good disease tolerance, which makes it one of the most reliable large watermelons for the home garden. If you want the classic slice-and-share summer melon, this is the one to grow.

This is the quick guide to Crimson Sweet. For the full step-by-step on starting seeds, sowing, feeding, and troubleshooting watermelons, see our complete guide to growing watermelons from seed.

Quick start

Sow seeds about 1 inch deep in warm soil at least 70F, on a raised hill or mound, or start indoors 3 to 4 weeks early in peat pots. Thin or space plants 3 to 4 feet apart in rows 6 feet apart and let the vines run. Water deeply and evenly, easing off as the melons ripen. Harvest around 85 days when the tendril nearest the fruit dries, the ground spot turns creamy yellow, and it thumps hollow.

Best tip

Crimson Sweet is a big melon that needs a full, warm season, so give it heat and time. In short-summer or cool regions like the North and Pacific Northwest, start seeds indoors 3 to 4 weeks early, warm the soil with black plastic, and do not transplant until nights stay above 55F. Water deeply and evenly while the fruit sizes up, then ease off in the final couple of weeks to concentrate the sugars for that signature sweetness.

At a glance

Botanical nameCitrullus lanatus

Plant typeWarm-season annual vine

USDA zones3 to 12 (grown as an annual)

SunFull sun (8+ hours)

Days to maturityAbout 85 days from transplant

Height12 to 18 in tall; vines 6 to 10 ft

Spacing3 to 4 feet apart; rows 6 feet apart

WaterDeep and even; ease off as fruit ripens

Uses

Crimson Sweet is the quintessential eating watermelon. Slice it into wedges for picnics and cookouts, cube it into fruit salads, or blend the sweet red flesh into juice, agua fresca, and summer coolers. It pairs beautifully with feta, mint, and lime, and its firm texture holds up well when cut ahead. Even the rind can be pickled.

Frequently asked questions

How long does Crimson Sweet watermelon take to grow?

Crimson Sweet ripens in about 85 days from transplant. Give it a long, warm season in full sun, and start seeds indoors 3 to 4 weeks early if your summers are short so the big melons have time to finish.

How big does a Crimson Sweet watermelon get?

Crimson Sweet produces large, round melons averaging 15 to 25 pounds, with a light green rind marked by darker green stripes. Inside is firm, deep red flesh that is crisp, very sweet, and holds few seeds.

What is Crimson Sweet best used for?

It is the classic all-purpose eating watermelon, perfect sliced into wedges, cubed for fruit salads, or blended into juice and agua fresca. Its high sugar content and firm texture make it a favorite for summer picnics and cookouts.

Is Crimson Sweet easy to grow?

Yes. Crimson Sweet is prized for its tolerance to fusarium wilt and anthracnose, making it one of the more reliable large watermelons. Give it warmth, full sun, room to sprawl, and steady water, easing off as the fruit ripens for the sweetest melons.

How many watermelons does one Crimson Sweet plant produce?

A healthy Crimson Sweet vine usually sets 2 to 4 good-sized watermelons per season. Give each plant plenty of room, full sun, and steady water while the fruit sizes up, and it will ripen more melons instead of dropping young ones.

Ready to grow your own? Heirloom Crimson Sweet seeds give you big, round, super-sweet melons perfect for slicing all summer. For the full step-by-step, see our complete watermelon growing guide linked at the top of this page.

Crimson Sweet Watermelon Seeds – Non-GMO HeirloomHeirloom, non-GMOHeirloom Crimson Sweet watermelon — big, crisp melons with deep red flesh.

Price$4.99

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Want more watermelons? These value packs pair Crimson Sweet with other varieties:

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Summer Vegetable Seeds Variety Pack – Non-GMO HeirloomWatermelon + summer cropsSugar Baby watermelon plus 24 more summer fruits and vegetables in one pack — the easiest way to fill a warm-season garden from a single order.

Price$27.99 Sale Price$24.99

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Vegetable Seeds Variety Pack55 veggie varietiesOur biggest vegetable collection — 55 varieties and over 11,500 seeds to stock a whole summer garden around your melons.

Price$21.99Starting at$17.99

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By Maxim Kaufman — Founder & CEO, Organo Republic

Maxim founded Organo Republic in 2017 and personally selects, tests, and grows the heirloom, non-GMO varieties the company offers. Under his leadership, Organo Republic was named Agri Business Review’s Top Non-GMO Seed Variety Solution 2026.