Orange Hokkaido squash problems

[Starlingbird]

Hi all! I have just joined the forum as I need some help with my squash plant. I hope I am posting in the correct section!

Ok, so my plant is doing very well as far as size and foliage goes. It had a problem early on with yellow leaves, but this got corrected with Doff Growmore 7-7-7 (the local nursery suggested this product as they believed the issue was due to lack of nitrogen). I am getting male and female flowers and small fruits, but the fruits develop tiny brown, circular speckles, which then join together and the fruit rots I have one large squash on the plant and that is healthy, but none of the others are getting beyond baby stage. Can anyone suggest what is happening here please?

The variety is an organic Orange Hokkaido squash. I have never grown this type before and usually grow Butternut squash. I am a bit of a novice gardener, by the way.

Thank you in advance for any advice and suggestions.

[Plot70]

Squashes regulate the number of fruits they carry.
The hot weather cut my marrows down to one per plant.
It was so hot that toe roots can't get enough water to more than one fruit.
My marrows are beginning to set more than one fruit now it is a bit cooler.

[Snoop Puss]

Hello and welcome. Lots of friendly folk on here glad to share their expertise and advice.

Can I ask a couple of supplementary questions that might help people come up with a diagnosis?
Are you hand pollinating or just letting insects do the work for you?
Also, if you break open one of the rotting ones, what do you find inside?
And are you growing butternut squash too and, if so, are they OK?

[ameno]

That's an unmistakable sign of aborted fruit.
There are two possible reasons, one is water stress, as Plot70 suggested about (either the plant is outright too dry, or else the plant already has fruit set and it thinks it can't manage any more).
The other possible reason is lack of sufficient pollination. Sometimes you'll find that fruits swell to about tennis ball size before stopping and eventually rotting. This is always insufficient pollination.

I would recommend upping the watering and also hand-pollinating the flowers - just pull off a male flower, remove the petals, and rub the pollen into the stigma of a female flower. Morning is the best time to do it, as the flowers open first thing and are only open for 1 day.

[Starlingbird]

Wow, thanks for all the great info everyone! I am growing a few things for the first time this year, so I have a LOT of learning to do

I have been letting the insects do the pollinating because I thought the fruit were doing ok (I didn't realise they could grow a bit when they hadn't been pollinated!).

If I break the fruit open they are totally fine inside.

Some of the tiny ones are getting blossom end rot. Could this be due to under-watering too?

No other squash being grown this year. Funnily enough, my courgettes are not doing great this year. They start shrivelling at the blossom end (like they are dehydrating). I was wary of over-watering, but now I'm thinking I may have been under-watering.

Thank you for all the info, I really appreciate it.

[Snoop Puss]

Underwatering a possibility and no pollination affecting both your courgettes and your squash by the sound of it. They're both quite large plants, so will need a lot of water, especially the squash.

I know my situation is different, but to give a comparison: my tomato plants outdoors get 2.5 l of water a day each, my squash plants easily double that.

[Starlingbird]

Thanks Snoop Puss. I will definitely be watering them this evening and be on pollination duties first thing in the morning. It's such a disappointment having such big, lush-looking plants, then have so little produce!

It's all such a learning process

[Starlingbird]

This is the plant. I am very proud of it, despite the lack of fruit lol

[Plot70]

There is a lot of brickwork there to soak up the sunlight. I would say it is heat related.
The growing container is possibly a little small and is slotted at the front so may not retain enough water.
The leaves on my squashes wilted even with the soil moist at the peak of the heat. They have now recovered and doubled in size in the following couple of weeks since we have had some cloud cover.

[Starlingbird]

Thanks, Plot70. Despite some crazy heat recently, the plant didn't wilt. I don't have much room and just grow things in raised beds at the moment, but will keep the points you made in mind for the future. I have grown squash in that spot before with no issues, but we have had a very dry summer and a couple of days where my garden reached 49.9 deg C!!!

Looking at all the points made, there are definitely a few probable factors affecting my squash plant. I hope there is still enough time to get a bit of produce from my plants if I rectify the water and pollination issues!

[ameno]

I have been letting the insects do the pollinating because I thought the fruit were doing ok (I didn't realise they could grow a bit when they hadn't been pollinated!).
.

Unfortunately insects can be a tad unreliable for squash (and also courgette) flowers. I think it has to do with the sheer size of the flowers - they're so big that the bee often largely misses the anthers or stigma of the flowers, and so can get to the nectar without actually pollinating it.

As for them growing a bit first, this happens when the fruit is partially pollinated but not pollinated enough to grow properly.
Basically, every single seed inside the fruit needs a separate grain of pollen to pollinate it. The fruit doesn't need all of the seeds to pollinate in order to grow properly, but it does still need a majority. Fruit growing to tennis ball or fist size before aborting happens when a few of the seeds have pollinated, but not enough to actually release enough of the growth hormone to make the fruit grow properly.

[Starlingbird]

Thanks for all that info Ameno, that's all so interesting to learn! I didn't realise how little I know lol. I'm really excited about making some changes now and seeing if there are improvements.

At the moment I have only got a strip of raised bed area along the base of a South facing wall, but I have French beans, peas, carrots, courgettes, squash, tomatoes, cabbage and one chilli plant (don't know if the chilli will work, but I'm just testing things out this year).