The first hollyhocks I grew in my garden were black hollyhocks in memory of an old neighbor who grew them when I was a kid. These hollyhocks were biennial, from seed they take two years to complete a life cycle, and I didn't save any seeds and so lost both of them.
Why didn't I save seeds from my hollyhocks? Not really sure why I didn't since hollyhock seeds are easy to collect. If you have a hollyhock in your garden that you really like, you should save some seeds from it every year and sow them.
Collecting and saving hollyhock seeds is very simple.