Hi Dale,

" I haven't been using fertilizer as I think I've read that that can make the stems weak "

Farmers use fertilizer. I use fertilizer and I ate breakfast and I don't feel a bit weak. If you read that fertilizer can make stems weak, maybe you stop reading altogether, starting right here.

ZM

https://extension.umd.edu/resource/why-some-flowering-plants-fall-over#:~:text=Plants%20that%20are%20grown%20in,under%20different%20conditions%20may%20not. Apparently, it can make stems weak.

In case you didn't bother looking at callirhe123 's link from The University of Maryland Extension

Plants that are grown in rich soil, with high levels of fertilizer and moisture, will produce more lush vegetative growth with weaker stems.Plants grown under these environmental conditions may require staking, while the same plant species grown under different conditions may not

play nice ZM

Thank you callirhoe123 !

You're welcome!