Update: one of my other pumpkins (tennis ball size) now is all split. What the heck is with that?

post pics if you can.

Its easy to tell when a pumpkin is going to make it or not. When a pumpkin is pollinated and the plants wants to keep it, it will grow very quickly. The next few days after pollination are critical. They seem to grow at the quickest rate that first week. I can usually tell a pumpkin will die if in the first week of its life, it hasn't grown for a few days. Their growth is pretty noticeable!

Fireduck, where are you located at? Is it really hot there?

I am in SoCal...and my weather is ideal. I still have one on the vine (almost tennis ball sized)...but I do notice the stem is yellow. Is that a concern? What caused my other one to split in about 3 places down the sides? I am old...and I can't do photo online. haha

I'm in so ca too. It's disappointing, but for me baby pumpkins often don't make it. May be not pollinated? They usually drop off smaller than tennis ball size so sorry to hear you lost one that size. I have a huge messy vine but only two pumpkins but maybe more will develop but it better hurry.

Fireduck I hope you get a pumpkin or two.

thanks socks...I hope you get some too. I stuck a couple in the ground...I bet they will do better than my container plants. I am a rookie at pumpkins...so I am kind of learning on the fly. My leaves are getting yellow/dry and I am not sure what gives.