On May 22nd, 2015 I planted 2 crimson sweet seedlings in a fairly large pot. The pot is 24-28 inches wide and 20 inches deep or so. I live in Virginia by the way in case that is helpful. I used 100% Miracle-gro Organic Garden soil. After 19 days there was very little growth. In that time they might have grown 2 inches each and maybe had 4 new leaves each. I later found out the soil was too dense and I saw someone mention that it says on the bag to not use the soil in pots. I can not find where it says that at all.
On the 20th day after planting I got some garden soil out of my granddads garden and replanted the plants and used some Miracle-gro shake and feed fruits and vegetables. The very next morning there was a noticeable difference. The main vine on each had grown .50 to 1 inch. On June 14th, 4 days after replanting, they were about 5 inches longer with new vines sprouting out. On June 23rd to June 26th, 12 days after replanting, saw an explosion in growth. To this point both plants were stiff and both inside the boundaries of the pot. On the 26th they had fell over the sides of the pot by about 8 inches. 4 days later they had grown another 5 inches with the leaves doubled in size.
On July 2nd I had to move it to another area so I could mow. I dug a hole in an area we don't use. Laid down some window screen with a hole in the center so the pot could set in it. I laid down screen in hopes of retarding weed growth. So far so good. I did place some stones down in certain places so it would lay flatter where the thicker weeds were. So having the pot in this hole allowed the vines to reach out straight instead of putting pressure on the base as if flowed over the sides. That evening, July 2nd, the first flower popped open. From July 2nd to July 6th, around 15 buds had appeared, about 9 had opened. July 6th was also the day my first watermelon appeared. At this point the entire area of vine grow was 5 square feet.
Since July 6th, I've had a total of 9 watermelons start to grow. 3 have disappeared and 1 is more than likely going to shrivel up and fall off. However I have 4 that are healthy and about the size of a baseball and another that is still really small but looks healthy. So I have 5 total growing good.
Sorry for having you read all of that but I wanted you to have a good idea of everything. So here is my concern. The vines, usually at soil level up to include some of the leaves, will turn a creamy yellow color. Some of the leaves with dry up and fall off. I figured this was over watering because there have been stretches of a lot of rain. I wouldn't water for a few days. They would start to turn green again. I will check the soil and if it's dry a ways down I will water. But sometimes after I water, not over water, the vines will have turned that yellow color again. After a few days they turn green again. This time I hold off on watering and they turn yellow again with very little water. At this point I don't know if it's the water doing it or something else. It's really odd. About 4 days ago the vines turned a little yellow, not to bad, I watered them and used some more fruit food and the vines started turning green again. So I don't know what's up. Hopefully someone can give me a better assessment of what's going on and maybe give me a few pointers. Thanks.