[HaggisWhisperer]

I am growing some squash (winter and summer) in my greenhouse. Although I have been fertilizing the female flowers using a paintbrush I think that a couple of the flowers were maybe not properly fertilized as the tiny squash doesn't seem to be getting any bigger. I've got other squash of the same variety that seem to be growing fine. Do I just leave the unfertilized squash to drop off naturally or should I cut them off the plant?

I'm not surprised there are fertilization problems - it seems that all the plants (summer and winter alike) decide to produce either all female or all male flowers at the same time before switching. Don't suppose there is anything I can really do about that ...

[realfood]

I would just leave any unfertilized squashes to drop off naturally. The method I use for fertilizing squashes under cover, such as cold frame or lidl mini tunnel is detailed on my web site:-
When the Winter Squash start to flower, provide access to the bees to carry out pollination. If you are growing them under cover or in a greenhouse, you will have to hand pollinate the female flowers, as shown in the photo on right.

Pick the male flower when the pollen is “mobile”, and carefully strip off the petals. Insert the pollen bearing male anther(yellow) into the middle of the female stigma(orange), making sure that the pollen grains are transferred.

[Salmo]

You should be able to use flowers from courgettes, marrows or pumpkins to pollinate squashes and vica versa as they are all closely related and cross pollinate each other. The resulting fruits will be the squashes you expect but seed from them will produce hybrids.

[mumofstig]

Well i never knew that............every day's a school day