When were they last lifted and separated? That might cure the problem for next season.
Looks like you found out when to dig. Enjoy, nothing like the taste of homegrown!
Doesn't look like what I'd call leaf beetle damage.
This is what i had at home in May on new shoots after i had harvested the early growth. The new shoots all came up with this damage.
For earlies 90 days from planting to lifting. Second earlies 100 days and maincrop about 110 to 120 days.
Most likely it is the green leaf beetle. Don't know of an organic cure, Used Provado bug spray but didn't harvest any rhubarb since.
Failte to you both.
Give me cow manure anyday this stuff is terible. What can I put it on and do I have to dilute it.
Does nettle feed smell to high heaven or did I do something wrong?
Greetings neighbour and best of gardening from Tipperary.
No fear Dove always keep it in a bucket with a lid on.