Black Diamond Melon Care: Growing Black Diamond Watermelons

Black Diamond Melon Care: Growing Black Diamond Watermelons

By: Tonya Barnett, (Author of FRESHCUTKY)

There are many key aspects that gardeners take into consideration when deciding which varieties of watermelon to grow in their gardens each season. Characteristics such as days to maturity, disease resistance, and eating quality are paramount. Another very important aspect, however, is size. For some growers, choosing varieties which produce large melons is non-negotiable. Learn some Black Diamond watermelon info in this article.

What is a Black Diamond Watermelon?

Black Diamond is an heirloom, open-pollinated variety of watermelon. For generations, Black Diamond watermelons have been a popular choice for both commercial and home growers for many reasons. Black Diamond watermelon plants produce vigorous vines, which often yield fruits weighing in excess of 50 lbs. (23 kg.).

Due to the large size of fruits, gardeners can expect this plant to require a long growing season in order to harvest fully ripe melons. Mature melons have very hard rinds and sweet, pink-red flesh.

Growing Black Diamond Watermelons

Growing Black Diamond watermelon plants is very similar to growing other varieties. Since all watermelon plants thrive in sunny locations, at least 6-8 hours of sun each day is imperative. Additionally, those wishing to plant Black Diamond will need to ensure a long growing season, as this variety may take at least 90 days to reach maturity.

To germinate watermelon seeds, soil temperatures of at least 70 F. (21 C.) are required. Most commonly, seeds are direct sown into the garden after all chance of frost has passed. Gardeners with shorter growing seasons attempting to grow Black Diamond watermelons may need to start seeds indoors in biodegradable pots before transplanting outside.

Harvesting Black Diamond Watermelons

As with any variety of watermelon, determining when fruits are at peak ripeness may be somewhat of a challenge. When attempting to pick a ripe watermelon, pay close attention to the tendril located where the melon connects to the plant stem. If this tendril is still green, the melon is not ripe. If the tendril has dried and turned brown, the melon is ripe or has started to ripen.

Before picking the watermelon, look for other signs that the fruit is ready. To further check the progress of the watermelon, carefully lift or roll it. Look for the place in which it was resting on the ground. When the melon is ripe, this area of the rind will usually have a cream-colored appearance.

Black Diamond watermelon rinds will also harden when they are ripe. Try scratching the watermelon rind with a fingernail. Ripe melons should not be able to be easily scratched. Using a combination of these methods when picking watermelons will ensure a much higher likelihood of choosing a fresh, juicy fruit that is ready to eat.

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Read more about Watermelons

Watermelon Fertilizer Tips

Over the years I’ve had many successes in my gardens. From peppers and tomatoes to fresh herbs and onions, my harvest has (for the most part) been plentiful. When it comes to watermelon, however, I seem to have fallen flat.

Year after year I’ve tried and failed to grow the round melon no matter the type, size, or location. I’ve tried Black Diamond Watermelon and Charleston Gray Watermelon, heck, I’ve even attempted to use watermelon seeds from the fruit at the grocery store.

Finally, I asked, “what gives?” and dug (literally) into some research.

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Have you tried hand pollination?

The female blossoms are out near the far end of strong runners. They have minature fruits behind the blossom and need pollination before noon. To pollinate, pick a male blossom [bright gold color] and pick off the petals and kiss the female [light yellow with green center] blossom lightly and thourally.


Which variety of BD are you growing? If you're growing regular BD or Florida Giant, you're going to have a long wait, and maybe not full ripening. Yellow Belly BD is much more reliable and a better producer. We're having the same weather and I'm watering mine for an hour every day. I get a second crop with YB, and they size down well.

How to grow Black Diamond Watermelon?

Black Diamond Watermelon plants have sparse leaves and need a lot of sunshine and heat to mature their fruit. The Black Diamond Watermelon plant roots are delicate and require high nutrition and lots of water. For all that effort, you’ll be rewarded by the ripest, sweetest watermelons you’ve ever tasted. Read through the handy and useful guide ‘How to Grow watermelon’ and grow refreshing flavorful watermleons this summer!

It is essential to start Black Diamond Watermelon seeds indoors or in a greenhouse mid to late April. Transplant at the end of May or first week of June, when the plants are 5 weeks old. Optimal soil temperature for germination: 20-25°C (68-77°F). Seeds should sprout in 5-10 days.

Sow Black Diamond Watermelon seeds ½” deep. Set transplants 24-36″ apart in rows 5-6′ apart.

Ideal pH: 6.0-6.8. Choose a warm, well-drained soil for Black Diamond Watermelon. Add dolomite lime and compost or well-rotted manure to the bed and ½-1 cup of complete organic fertilizer beneath each transplant. Watermelons need really warm growing conditions. Use black plastic mulch, cloches, or floating row covers. Success may improve in raised beds. Watermelons plants require 8-10 weeks of good, hot growing weather from the middle of June to the end of August. During that time, a melon vine must grow 5-9 leaves before starting to flower, then set 4 or more male flowers before making its first female flower, and then ripen its fruit before cool, damp weather sets in. Watermelons do not ripen off the vine. During the entire growing season, make sure to provide ample water.

Black Diamond Watermelon fruit will ripen in late August to early September. Watermelon is ripe when the tendril nearest to the fruit withers and dries up.

Seed Info
In ideal conditions at least 60% of Black Diamond Watermelon seeds will germinate. Usual seed life: 3 years. Per 100′ row: 60 seeds, per acre: 5.2M seeds.

Click link for more non-GMO, untreated watermelon seeds

Watch the video: How to grow GIANT watermelons