Zucchini plants were growing pretty well ... till this happened. Started on one and now all of them have stem damage like this.
Can some one please help.
Looks like squash vine borer damage. You can search for this (or "SVB") on the search function on this website or google it. It is a very common problem.
I think Black Beauty is a resistant zuke plant. So sorry! They got my nice yellow crooked neck squash last year. There are some plants in the Cucurbit family that are SVB resistant. Such as Cushaw squash and Blue Hubbard squash. Gardening is a learning experience. I learned so much this year, it hurts!
Yes, Squash Vine Borer. Mine fell victim this year too. I have panted a second crop to see what will happen with a later season planting.
Gotta get those buggers at the egg stage, if possible. Very tiny single brown eggs usually laid on the lower part of the stem. Not to be confused with the squash bug eggs which are an orange cluster usually on the back side of the leaves. Both should be removed by hand when discovered.
The link below I an interesting read.
Here is a link that might be useful: Squash Vine Borer Control
Thanks all for the replies. I slit the plants at the base and started looking for the bugs... to my surprise it was not one or two ... there were families of them 4 or 5. Finally felt the plant would not survive the operation. So pulled all of them out. Infact all of them had SVB damage. - what a lesson learnt - I lost all my zucc plants.
I will be more careful from here and try to protect my winter squash plants now.