Black Diamond Yellow Belly Watermelon Seeds


No, there is nothing cowardly about this heirloom watermelon. Rather, the name comes from the big yellow spot that forms where the rind rests on the ground. 

This giant variety produces globular melons weighing 14-22 kilograms apiece. Fruits can be expected to ripen in 90-95 days from when the seeds sprout or transplants are set into the garden. With plenty of sun and space, vines will creep out 3-5 meters, flowering and fruiting as they sprawl. 

Contained within a thick, dark green rind, bright red flesh is juicy and super sweet. The astounding size and classic watermelon flavour will conjure nostalgic memories of sugary, summertime snacking.


- Latin Name: Citrullus lanatus
- Life Cycle: Annual
- Days to Maturity: 90
- Planting Depth: 2-3 cm
- Plant Spacing: 60 cm or 30 cm with trellis
- Row Spacing: 1.5-1.8 m
- Growth Habit: Short-vine spreading


In the blazing heat of a summer afternoon, what’s more quenching than enjoying a juicy, sweet slice of watermelon? Watermelon for sure is more prevalent in warmer climates, but growers in cold regions can have success starting seeds indoors. This summertime gem will need plenty of sun and space, but can easily be started from seed. From the day of planting it can take up to 100 days to harvest, depending on the variety.

Start seeds 2-3 weeks before the last frost date. Plant into separate pots, about 1 cm deep. Use slightly larger pots than usual  to accommodate expansive root growth. Or, compostable pots may be a good option. They can be transplanted directly with little disturbance to the roots. If kept moist  and at a warm temperature seeds should germinate within a few days. Provide plenty of light for the first few weeks.

When soil reaches at least 18°C, prepare to harden off and transplant. Watermelons tend to need an abundance of nutrients in order to produce their enormous fruits. So, prepare the bed beforehand with plenty of compost. Make sure this site receives full sun, has loose, well-drained soil and that vines will have plenty of space to spread. Transplant very carefully, roots are fragile and can be damaged easily. Either plant in traditional rows about 2 m apart, or in 1.5 m wide mounds, 60-90 cm apart.

Provide young plants with 3-5 cm of water/week until fruit are set. Reduce water at that point to promote the production of sweet fruit. Add mulch to retain moisture and provide a dry resting place for fruit as it matures.

Be good to your pollinators! Male and female flowers are produced and need healthy native insects to aid in fertilization.

To tell if a watermelon is ripe. Give it a slap! Hollow sounding melons should be ready. If the underside is a cream or yellow color, that is a good indicator of maturity. Finally, check the stem where it is attached to the fruit. If it is still green, wait. Once it starts to die off, or is dead, the fruit should be ready to pick. Snip the stem with clippers or a knife close to the fruit.

Watermelon is an essential sweet treat that every gardener should grow to help beat the summer heat!


- The first evidence of watermelon cultivation is in Ancient Egypt, where they were cultivated for their high water content and stored to be eaten during dry seasons. During the seventh century, watermelons were cultivated in India, by the 10th century had reached China, and by the 17th century, were widely planted in Europe.

- Watermelon seeds will remain viable for 4 years if stored in a cool, dark place, ideally between 4 and 10⁰C. After that, the germination rate may start to go down.

Notre garantie sur les semences

Vous savez qu'un jardin luxuriant et fructueux a besoin d'un bon sol, d'arrosages fréquents et du soleil pour pousser, mais ce sont les semences qui font vraiment la différence.

Cueillies et ensachées pour 2024, la grande majorité de nos semences ont des taux de germination de plus de 85 %. Toutes nos semences sont entièrement naturelles, sans OGM, non hybrides, non traitées et à pollinisation libre pour récolter les semences année après année.

Nos semences sont  soigneusement emballées dans des pochettes refermables, en papier kraft/aluminium de qualité alimentaire. Nos commandes sont ensuite expédiées dans des enveloppes rembourrées respectueuses de l'environnement.

Nous utilisons un scellage thermique pour chaque sachet de graines afin de garantir une protection maximale contre l'humidité , les odeurs et la lumière, vous permettant de conserver vos semences jusqu'à 3 fois plus longtemps que dans du papier ou plastique. Plantez-les toutes, faites-en germer quelques-unes à l'intérieur, gardez-en pour la saison prochaine - à vous de décider !