Hi! since HH are bienniel that means the first year they just have leaves and the second yr they bloom then die.
I've had some have green the third year but they never flowered and eventually died that year. So I find the ones here are bieniel. I've had others disagree. Maybe in your climate ( longer summer) you can plant the seeds now and have it still count as the first year and then bloom next year. Not sure.
I've planted the dbls like chatters pink, chattters yellow and chatters white. I've also grown singles but they are common.
I've preferred the look of 'peaches n cream' since they have 2 colors on the same stalk, but I quit growing them since they didn't self sow much- and needed to be staked to stand up with those heavy blooms.
2 yrs ago I decided toonly grow the black ones . I let them self sow rather than bother with collected storing and replanting seed.
I only had one plant bloom this year so they don't readily self sow either. Self sow = reseed. that answers that question. Never tried the creme de cassis.
With only one plant to bloom...I'm done with growing HH. I find the leaves itchy and unattractive. I'm not into staking everything. and the reseeding isn't enough where I have them planted, I'd have to put effort into seed collecting.
The bienniel thing is a problem for me. I want a lot of bloom time and 365d of nothing and then another 345 days of nothing is a long time to wait for 20 days of blooms. Especially on a plant that takes that much of my garden.
When I'm looking up a plant I type it in google and see what info is on the web. If I can't find out the annual vs perenial vs bienniel question I type in one of those 3 words with the name of the plant and see if the web finds an article putting those 2 words together. Just a thought for you. I see you've waited several days to find this answer. I'd just rather find out right away.
I agree with dahlianut. I've tried it both ways. I've succeeded with seed and failed with transplants. And the seeds are so much less expensive. Surprisingly, HH even tolerate rather heavy, dry clay. Most hollyhocks sown in spring do not flower until the following summer; but there have been breeding programs to speed things up; so if one hunts hard enough one can find ones that bloom the year they are planted. I've grown the Chater's double Peaches and Cream and it was frilly and delicious looking; but I had not planted it among the purplish flowers it would look best with (i.e. Cassis) and it clashed with everything around it. I kinda favor the old fashioned single ones; but it's a matter of taste.
I share the concern of waiting a year for twenty days of blooms. The old fashioned hollyhock growing in the front yard of a neighbor's bloomed most of the summer. So I guess when I planted seeds recently I was hoping for the same thing.
I have found them easy to grow from seed. I start them in May for planting out the next Spring. Chater's Double & Summer Carnival are both 1st year bloomers. I have some Summer Carnivals now started in May that have buds on them.
I have some seed from 50 year old HH seed from an old mining town. I am very excited for the info. I have them in growing cells in the greenhouse. Wish me luck. Next year at the round up we should have many seeds and plants.
These seeds are from my mothers front yard. I had to ask the current residents if it was OK to harvest seed. They said no problem. I actually think they thought I was nuts. I ordered HH from Wayside and planted them last year in the spring. One plant bloomed and the other two did not. I have the seed from the one that bloomed which was single bloom pale yellow. The other two plants are still alive. I will let you know how my experience goes. I think I paid at least $5.00 per plant and I think we can do better here on seed trading on DG. I did not think about my mother's 50 year old HH until I had ordered the plants.