Friday, 3 June 2011

The sex-life of the Marrow

Marrows, Courgettes and Cucumbers are sometimes slow to set fruit, especially if there are not many bees about, so I thought it might be useful to give a bit of advice about hand-pollination, which can improve the chances of getting a good crop.

OK, first off, learn to recognise the difference between male and female flowers. The upright Marrow flower in this photo is a female. You can see that it has an embryonic fruitlet behind the yellow petals. Unless the flower is fertilised by pollen from the male flower, this will not develop. [Ignore the developing Marrow fruit in the bottom left of the picture. This is the result of a previous successful union!]

This one is a (rather "past it") male. It has a long slender stem, without the embryonic fruitlet.

Here's a pair of prospective parents, looking vigorous and ready to "make babies". The fact that both types of flower are ready at the same time is of course an important factor.

I think you will agree that any self-respecting bee would find such an impressive array hard to ignore - and of course the normal method of flower-pollination involves a foraging bee's visit to a female flower shortly after one to a male flower, with pollen being transferred on the hairs on the bee's body.

Right, now let's look at the "bits"... These are the relevant bits of a female flower.

And this is the relevant bit of a male flower.

Now, the "act" itself. (Those of a fastidious nature, please look away now...)

What you do is pick the lucky male flower, (this is a one-off opportunity for him, you understand), strip off the yellow petals, exposing the central stamen, and then gently insert the male flower into the female, brushing the female parts with the male parts to enable pollen to be transfererred. Do it sensitively, with all due respect, of course!

If you prefer, you can achieve the same thing by using a soft paintbrush to take pollen from one to the other (but they may not enjoy it so much...).

Assuming successful pollination, the little fruitlet will begin to grow within a couple of days.  This is what it may look like 10 days later. Although it appears bigger in my photo, this Marrow is only about 10cm long. Compare it with that grey pipe, the diameter of which is 2.5cm.

You'll notice that I have placed a piece of tile underneath the fruit. This keeps it out of contact with the damp soil, which could cause it to rot.

Last year I only got two marrows off my Bush Baby plant. I'm hoping to do better this year, which is why I have carried out the procedure described above.


  1. I have trouble getting any summer squash to produce here yet my neighbor can throw it out in her yard in an old kiddie pool with old dirt and get bunches of squash and she never even has to water them! I don't know what I do wrong, lol.

  2. Becky; did you see Ali's post about tomatoes earlier today? It seems that the more care you give your crops the less well they will perform. Neglect seems to be the best policy!

  3. Hope you have many happy unions this whole coming summer,fall with cucurbits.

  4. Ha. Very informative... and entertaining.

  5. I do that same method with pumpkin and Zucchini here as we are a little short on Bees as well as all the rain we have been having. It is a wonderful method and most successful

  6. Thank you for the detailed pollinating tutorial. I'll try this the next time around.

  7. Mark, you need to get out more :p

    What exactly is that last one... you say marrow, but I don't actually know what a marrow is???

  8. Ali, "Marrow" is the name of the plant and its fruit. Zucchini / Courgettes are basically Marrows bred for harvesting young.

  9. I had the same question as Ali. Thanks for the bawdy pollination lesson! Last year we lost all of ours to vine borers. Hopefully this year will be better!

  10. Every year I am fascinated by how LARGE the embryo fruit is on a female flower. It looks ready to eat before the plant even opens the bud! I may try your manual pollination trick -- the first few squash to develop are sunken from low pollination in spite of the beehive nearby. Maybe there wasn't a male flower open at the time.


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