My Cauliflowers have gone limp overnight

My cauliflower was almost ready to harvest in then next week or so and is of tennis ball size. I went out to check them today as I do everyday and the leaves have gone all limp and soft.

What could this be and should I just harvest them now?

Thanks

 

Not sure why they have gone limp so quickly , but they look ready to me.
Surely not a water problem.

 

they could have. I haven’t been on my best watering game these last few weeks. I watered them this evening and will see if they perk up. They’re in a raised planter, I was worried incase it was a disease

 

you should have seen my others. Caterpillars got at my first batch and they was a mess. Thankfully I protected these ones much better from the butterflies