Hope this is not to long. I have been planting watermelons for 3 yrs. The last 2 have been awesome crops. I only plant about 12 plants. This year in Michigan we had a lot of heat and they didn't do so well. I create mounds about 12 inches wide 6 inches high, cover with black plastic with a 4 inch hole for the plant. This always works very well and this is how the farmers do it. This year the plants were doing great until the plant vines or runners got about 3 ft. long, then the leaves started to die. The plant looked pitiful but still they were producing melons. When the melons got about 8" wide, they started splitting open. 2 things I did different this year:
1) moved garden to a little higher ground that's not so muddy.
2) by advice, before making the mound, I dug out about 4" and put a half a shovel of manure then mounded the dirt. I did the exact same thing to my cantaloupes and they're doing fine.
I heard mixing a little mulch with the dirt will help with moisture. If this was a watering problem, when should I or should I not water? By the way, the plants are still producing new flowers but the way it looks I'm only going to get about 8 melons. Please help, I don't want this to happen again, too much work.
Certified GKH Gardening Expert
The splitting is a result of inconsistent watering. With the extra heat and the less muddy soil, the watering that you were doing before (and would have been fine) may now be causing the plant to get too dry and when it gets its water, it sucks it up rapidly. The melons, like water balloons, fill too fast with water and this causes splitting and cracking. Try watering more frequently to help prevent this.
When you put the manure in the ground, was it fresh or composted? If it was fresh, it may be burning the roots, which could cause the plant to die off some, with the ends dying first. Putting manure in the ground is good for plants, but you need to allow it to mellow for a few months or the high nitrogen content can burn plants roots.