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Female Pumpkin Blossoms Not Opening...

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  • Female Pumpkin Blossoms Not Opening...

    On both Small Sugar and Connecticut Field pumpkins, what few female blossoms that I am getting are not opening at all. They just turn yellow and fall off a few days after they appear.

    I have lots and lots of healthy looking vine (15 to 20 feet), but no pumpkins.

  • #2
    Quick questions... how much sun are they getting, what is your weather like, and have you used fertilizers?

    If female flowers open and then later abort, it is often lack of pollination... if they are not opening at all it is something else... so more info is needed to figure out what is wrong.


    • #3
      Thanks for your reply.

      They are getting at least 7 hours of direct sun. We've had a wet July, but just a bit over average. Drainage is good in that part of my garden. It's been a little cooler than normal, with daytime highs around 80 and lows in the lower 60's. We're headed into a pressure cooker for the next few days. The vines look great. The leaves are huge, side shoots are running and intermediate roots are forming -- just no punkins.

      I fed them with Espoma Plant-Tone shortly after their first set of true leaves, and a couple times over 2 months with Neptune's Harvest Fish/Seaweed.

      I'm reasonably confident the blossoms are never opening, as opposed to opening and not getting pollinated.


      • #4
        Pollinated flower

        What it looks like roughly the day before it opens:

        Borrowed pics... but you get the idea.


        • #5
          Sorry had to enter it before I clicked out and lost the pics all over again lol. Yes the 2nd pic is a male, but it gives you an idea what to look for in a flower that will open the next morning. Often they are open just before dawn and can close just a few hours later.

          This site has some pics too . Other thing to check is if the stigma has black streaks going towards the ovary. Stigma death.


          • #6
            I've got tons of male blossoms, all opening and attracting swarms of bees. I have a few female blossoms, but as I've said they are not maturing to the point of opening to receive pollination.


            • #7
              And you cut one open to see if the stigma has black streaks going to the ovary?


              • #8
                STIGMA DEATH
                In addition to pollination, development of female flowers may be affected by temperature. Recent experience in the Middle Atlantic states and in New England indicates that high night temperatures (above 65 F) are associated with failure of female flowers to open and develop properly. The ovaries turn yellow and then shrivel and the stigma of the unopened flower exhibits black streaks into the ovary.

                Just trying to track possibilities down. Only other thing I found is this:

                Someone else had the same problem... Here's what the North Dakota Agricultural Extension had to say about it:
                "The female flowers were tightly closed up with no access to the lobes that I'm supposed to transfer the pollen to. Any ideas? (E-mail reference, San Jose, N.M.)
                A: I don't know why the female flowers are not opening. Where did you get the seed? It could be a variety (cultivar) problem where your day-length, temperature extremes, or sunlight intensity is not conducive for reproductive activity. It may also be a fertility problem: pumpkins are greedy feeders of nutrients, but an imbalance of too much nitrogen could cause problems as well. Or, since reproduction requires an outlay of energy, perhaps the female flowers are not opening or aborting because they are grown in partial shade and simply have not accumulated enough carbohydrate reserves to develop pumpkin fruit. I would suggest getting the soil tested for nitrogen, phosphorus, potassium, soluble salt levels, pH, and organic matter content. Also, check to see what the amount of direct sunlight contact with the vines are. They need full sunlight to be productive."


                • #9
                  I just autopsied one. The shriveled yellow is spot on, but there are no black streaks from the stigma to the ovary.

                  Our nights have not been overly warm.

                  Thanks for all your research and help.

                  I have one Connecticut Field blossom that shows some potential to open. It is showing more color in the petal tissue than any of the others have so far.

                  I'm going to hit them with a good dose of Neptune's Harvest again this evening.


                  • #10
                    Finally had a female blossom open today. Just to be sure, I hand pollinated it, but there were plenty of bees around, too. Now we'll see how it develops.


                    • #11
                      I'm having the same problem with my sugar pumpkins -- tons of male blossoms, but what few females I have fall off before they ever open (and I know because I have been marking them and checking them every morning and evening). My plants are extremely healthy looking otherwise with lots of green foliage, strong vines and no mildew. They get full sun all day long. We've had a TON of rain the last few weeks and I was wondering if that was maybe the problem?


                      • #12
                        I don't think so, Sydney. Mine have done it through both wet and dry conditions. LUSH foliage, but no mature female blossoms. I finally got a couple of Connecticut Field that pollinated.

                        I have topped a lot of the vine with compost. I'll let you know in a few days if it helps at all.


                        • #13
                          Hi I need some info on pumpkins. Are y'all still on here. ?