The leaves are still edible even when seed has formed,though they will be more bitter and tougher than young leaves and not necessarily pleasant to eat. Dandelion root is best harvested in spring, when its at its most nutritious. Not sure what you mean by 'beneficial properties' though, other than that they contain the usual antioxidants, vitamins and minerals, and the leaves are diuretic.

Hi Anajanii and welcome to GoY, sorry, not sure what you mean by 'beneficial properties? The leaves of dandelion are good to eat in spring, not sure there are any other 'benefits'.

I'm only aware of it as a diuretic...

As my compost bin was half empty one time last year I threw a thick layer of dandelion leaves in, I hope I did right.

As long as you turned the pile right after, the leaves shouldn't have done any harm, Hank. Dandelion roots and seedheads, though, will cause problems wherever you spread the compost.

It's a good source of vit A and is a mild laxative too as well as the mentioned diuretic. I'm in my mid 80's so it makes a perfect addition to my salads.