Container Pumpkins (Jack OLantern)

Hello from NW GA!
I started gardening two years ago in 10gal grow bags.  The second year hubby decided to join me by cultivating j-o-l pumpkins but we started in July (zone 7b) - the pumpkins grew then stopped and hubby was frustrated and pulled the two he got off two separate vines (sadly they didn't make it to Fall).  
This year we decided to grow two kinds of pumpkins - Jack's and pie pumpkins.  We started them in May and now it's the end of June and they have all but stopped growing (the fruit, that is).  We were watering once a day with two 2 liter bottles of water but now are watering with 2 gal. water jugs.  It has been so hot in GA. so he's wondering if the fruit will get bigger - they are about the size of a large grapefruit.

Thank you for any help/info you can give.

Hi Julia,
Welcome to Permies!

The decorative pumpkins don't usually get much bigger than you are describing, but most others will get quite a bit bigger.

Heat can definitely stress out plants. I have no experience growing in the south, but I hear people describing plants essentially pausing during the heat of the summer, staying just enough alive and then getting another flush of growth later in the year when it cools off.

Lack of enough sunlight can stunt growth. Do you have any idea of how many hours of sunlight they are getting?

Too much water can also cause problems. Do the grow bags drain well?

Lastly, any sign of disease when they seem to stop growing? Spots, yellowing leaves, weird bulges or thin spots in the stem?

Thanks for responding, Matt.  The J's and pies are getting dappled sun from 8-11am, then full sun from 11-7pm.

No disease to speak of.  Used diatomaceous earth and neem oil as pest control.  Just received Farmers Secret Bloom Booster fertilizer so we're hoping that will help.

We have had a reprieve on the heat since the last post with the swirling storm to the southwest of us.  It has allowed for some rain and wind as well as cloud cover during the day.  

One plant died but I think a vine borer got to it.  Found a round brown area along the main vine.

As far as the grow bags are concerned they are made of a felt or Pellon material  and they drain very well (almost too well).  I do the finger test daily and even with a layer of grass mulch on top they dry out within a day.  I sink my index finger all the way into the soil up to my knuckle so probably 2 1/2"-3".

My container gardening is limited, but if things are drying out within a day, it does sound like they are draining too well. Perhaps something wrapper around the outside to limit the drying out? Perhaps a different soil mix for next year. Something to hold water better.