I pre-plant indoors. Tomatoes, cantaloupe, carrots, b. sprouts, cauliflower, and watermelon and other stuff.
I have success using potting soils. Everything grows well indoors.
But when I then plant them outside early to mid-May, they just do nothing for months. They don't die but they don't thrive or grow much.
It isn't until late June they begin to grow. Some plants better than others.
When I plant them in the ground the plants are stunted. They don't thrive.
I'm most frustrated by watermelon.
I have 4 different varieties I picked for short growing seasons. I have had only one year of moderate success.
Indoors the watermelon seedlings grow beautifully. Dark green leaves and solid stalks. They were a good 4 to 5 inches with full leaves and no yellowing or dying leaves.
But of all the plants I transfer outdoors, watermelon are always the slowest growing. While others grow moderately well, the watermelon just sit there for a couple months with almost no growth. They don't die but they don't grow.
Right now there are many SMALL melons which always appeared late. Too late to fully mature. I picked these 4 varieties because they're smaller and said to have shorter growing seasons.
Also at this point (early Aug), there are hundreds of yellow buds which have appeared too late in the season to do anything (bees love them).
They also suffer from lighter green leaves to yellow leaves.
From my observations and research, I have determined, because of slow growth, stunted plants, and yellow leaves, the problem to be nitrogen deficiency.
Everything else grows fine but they also do not grow quickly or really thrive.
I have tried to avoid using chemical fertilizers but I did use limited and small amounts of Miracle Grow (the lazy mans' 'fertilizer').
As far as I can tell, the problems all point to nitrogen deficiency and I suspect of all the plants I grow, watermelon are most affected by low levels of nitrogen.
After my observations I refined my research and found confirmation:
"Nitrogen (N) deficiency is the most common nutrient problem for watermelon production. N deficiencies at any time during the season can affect crop yield and quality, and deficiencies when fruit size ranges from 4- to 6-inches in diameter can be the most damaging. N uptake from the soil is usually low early in the season, before the runner stage. The uptake of N rapidly increases from early runner to 3-inch melon stages, when N uptake reaches its peak. When fruit reach the 6- to 10-inch stage the uptake of N starts to decline, and this decline continues through to the final harvest.2",/I>
http://www.seminis-us.com/resources/agronomic-spotlights/watermelon-nutrient-analysis/
That's my story.
If you have any personal success or failures growing watermelon or know which varieties grow best and fastest, I would appreciate your wisdom.
I’m a Master Gardener (but not the snooty kind, LOL!) and I have YET to grow a decent watermelon. So, I gave up and moved on to other successes.
Beau tries, too. This season he has some lovely Honeydew, and I did buy him a watermelon plant, but it is doing the same thing yours are. Lots of blooms, no fruit.
He did have luck a few years ago with ‘Moon and Stars’ watermelon, which is an old heirloom variety...but still, only a few melons off of what seemed to be an ACRE of vines.
I DO know that they need a LOT of water and warm soil; up here on The Frozen Tundra, people put down black plastic to heat up the soil faster, and then mulch like heck with lots of straw in the melon patch.
I have no answers for you, but I agree with the Alfalfa Meal for organic nitrogen. I suppose your watermelon success will depend upon water, nutrition, warm soil, the general weather in any growing season...and how stubborn you are, LOL! ;)
Dad claims that his Grandpap grew the best watermelons in the county.
Said the secret was to dig a hole a foot deep and two feet around, and fill it with fresh horse poop, make a hill of dirt on top of the poop, and plant the seeds in the dirt hill.