Hardiness Zone: 8a
Tennie from Sherman, TX
There are three factors that will cause the growth of melons to come slow down (or stop): cool temperatures (below 60ºF), too much water or too little water. When melons don't get enough water they stop growing. Don't over-water them or the vines will collapse, but continue to keep them well watered like you have been doing and remember that the larger they get, the more water they will need. Allow the top 1 to 2 inches of soil to dry out between waterings.
Make sure you're using the right fertilizer. Use one with 4 parts phosphorus to 1 part nitrogen to promote larger vines and better fruiting. Ideally, this would have been added to the soil at planting time. Adding additional nitrogen after 1 month and again 2 months after planting will keep your vines growing.
Cool temperatures are probably not your problem. Although watermelons like heat, the extreme temperatures this summer have been hard on everything. You can help prevent any further stress to your melons by keeping the vines free of weeds. Melons don't like to compete for nutrients. Even small weeds can stunt their growth and result in smaller melons.
As long as the leaves and vines on your melon plants continue to look healthy, I suspect the slowdown in growth is probably only temporary. If you feel like you have a sufficient number of melons started, you can help to increase their size by removing any remaining flowers on the vines. This will channel all of the plant's remaining energy into expanding the fruit that is already there. Of course the final size of your melons will depend on what varieties you're growing.
I've never grown these particular melons, but I'd think they require a lot of water. Watermelons are mostly water and sugar.
Can you fix up some type of drip irrigation? You know like a hose with tiny holes in it laid alongside the plants. Then leave the water turned on so the plants get watered really deep. I'd say 20 min or half hour per day.
I sure hope someone else can give you some feedback.
my watermelon get to large grapefruit size , then split open long before size or ripe ?any thoughts?
Surprisingly I have a couple of cantalope out of a 3 3 x 3 foot "cage" garden I read about but didn't place enough or right ingredients into when starting.
I think we're all having a poor veggie garden this year! My bees aren't doing their job with the zucchini. But they are with my tomatoes! Sometimes you have to self pollenate by using a Q-tip transferrring pollen to the flowers. I've done this...it works- but it's a chore!