Squash family not forming fruit?

The squash or Cucurbit family that includes chokoes, cucumbers, grammas, gourds, pumpkins, rockmelons, squash, watermelons, and zucchinis, produce both male and female flowers on the same plant, and rely on insects, such as bees, to pollinate the female flowers and produce fruit. (Although we eat many of this family as vegetables, in gardening terms, their produce is fruit.)
If bee activity is low, flowers of this family remain unpollinated, and fruit is unable to form. When this happens you may have to hand pollinate your plants to reap the benefits of your hard work. This is quite a simple procedure.
First identify the the female flowers on your vine or bush. At the base of each female flower you will find a miniature version of the mature fruit of that particular species. For example, cucumber vines produce what looks like a tiny gherkin at the base of each female flower while watermelon produce a watermelon miniature, often complete with stripes. The bases of male flowers, on the other hand, join directly onto a vine stem. See examples below.

Cucumber flowers – Male on the Left, female on the right.

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Zucchini flowers – Male on the left, female on the right.

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handpollin To hand pollinate, take a clean, dry, soft bristled paint brush and ‘tickle’ the centre of a male flower to collect pollen on the tips of the bristles, then gently transfer the pollen to the stigma at the top of the style in the centre of female flowers. (Image shows hand pollination of female cucumber flower.)
Or, you can remove a male flower from the vine, and carefully peel back the petals so that the pollen bearing part in completely exposed. Then dab the centre of the male flower into the centre of a female flower. Repeat this process, replacing the male flower as pollen is removed. Then stand back, and allow nature to take its course.
If you can only find male flowers on your cucurbit vine, the problem takes a little longer to overcome. Pinch off the end of each long runner. This will stimulate the plant to produce side shoots called laterals. Some members of this family tend to produce female flowers on laterals. Once female flowers form, proceed with hand pollination if there are not many bees around.

Pumpkin update

Now that the pumpkin vine is dying off, we are able to find the entire crop – 27 pumpkins from one vine. Compost and plenty of water are the secrets to healthy pumpkin growth. Despite prolonged periods of rain, the vine has remained healthy without a hint of mildew because full access to nutrients has provided the vine with a healthy immune system. The only down side to this luxurious growth has been that it has provided a multitude of places for our chooks to hide their eggs.

Saving pumpkin seed

If your pumpkin vine has performed well for you this year, it is worth saving seed from one of the best pumpkins as the plants that grow from collected seed will have already adapted to your soil and climate conditions, and pumpkin seed is very easy to save. After harvesting, store the pumpkin for 2 or 3 weeks to make sure the seeds are fully mature. Then cut the pumpkin and scoop out the seeds. Place the seeds in water and rub them to remove the pulp. Viable seeds usually sink to the bottom of the container. Rinse the seeds well, then spread the seeds on a sheet of paper to dry where mice can’t get to them. After two weeks, place seeds in a labelled jar or envelope and store in a cool, dark, dry place.

Harvesting pumpkins

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It’s about time to harvest pumpkins again. Our pumpkin vine this year was a volunteer that sprang up in the chook run from the remnants of an old compost heap. It didn’t get any TLC because we half expected the chooks to trample it before it became established. However, it defied the odds and performed magnificently – which only goes to show how good compost is for growing vegetables.
I think it was only watered once but it received plenty of rain during its growing period, and the vine has produced at least 14 JAP pumpkins that we have found so far. JAP pumpkin is closely related to butternut pumpkin, gramma and trombone squash (Cucurbita moschata). These are thinner skinned and don’t keep as long as the Queensland Blue types (C. maxima).
Because we couldn’t spare the water last year, we bought all our pumpkins and some of them weren’t the best because of the drought. Consequently, we were curious to see what we could expect from our volunteer plant and picked one of the pumpkins early. (As you can see in the photo below, the stem is still moist.) Pumpkins picked at this stage do not keep well but we are using this pumpkin immediately, so it doesn’t matter. Now that they are nearly ripe, we will put a broken piece of foam box or thick cardboard under each fruit to keep them drier and clear of the ground, so they are less likely to rot. We will be leaving the rest of the crop until the vine dies off, and the stems become brittle, as that is when they develop their full flavour and store well. If you can’t wait that long, at least wait until the tendril closest to each pumpkin browns off.
Don’t worry about frost on your pumpkins, it will only kill the vines, and it is said that frost toughens the skins so that pumpkins keep longer.
P.S. When the vines had died back a bit, we realised that the vine had produced 28 pumpkins. Not bad for a volunteer vine! There were, of course, more than enough to supply family and friends, and we were able to sell the rest through our local organic greengrocer.
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