(Grin.)
I’ve tried a whole bunch of colors now, and I can report some trends you may look for.
Older leaves are sandpapery, which I don’t love. The roughness disappears when they’re cooked, though. They taste fine – like an edible leaf. Perfectly palatable. If you want them tender and mucilanginous, eat the leaf buds and young leaves. Think okra.
Fresh flowers have no flavor. The petals are slightly rubbery, and they basically taste very mildly like lettuce and nothing else.
Dried flowers are way better. When they’re dried, they taste like . . . marshmallow! 
That’s right, they’ve got the same flavor as their cousin, the marsh mallow plant. This seems to depend on the color of the flower, though. The hollyhocks that volunteered in my yard are black, and the dried flowers have a nice, strong marshmallow flavor. I can crumble them into shortbread or add them to hot chocolate for yumminess. Or just snack on them straight off the plant.
The lighter the color of the hollyhock flower, the less flavor they seem to have. The white ones are totally flavorless. The light pink ones have a faint taste. The dark pink ones have a bit of a taste. The black ones have a strong taste.
You can pick the fresh flowers and dry them if you want, but if you live in a climate with little summer rain or humidity, there’s an even better option. I leave my hollyhock flowers on the plant until they obligingly dry themselves down, then pluck the dried flowers off each young seed pod that’s forming. They slide out easily, disturbing nothing. By doing that, I get to eat all the flowers and still get all the seeds. Neat!
Since hollyhocks bloom abundantly all summer long, you can be picking a few dried flowers off your plants every few days. Since they’re dried, you can eat them immediately or stick them in a bag and store them for later. I usually fill a large ziploc bag up with dried flowers and stick it in the freezer for a few days, just to make sure no bugs traveled with my flowers that might eat them, but I don’t think the freezer step is really necessary. I rarely see bugs in the dried flowers.
I often see bugs in the maturing or fully mature seed pods, though. We have these invasive red bugs that love eating those seeds. So if you’re saving hollyhock seeds, and you have those bugs in your climate, you definitely need to freeze the dried seeds. If you don’t freeze cycle them, you’ll have a bag full of powder that’s crawling with bug larvae after a few months. (Ask me how I know.)
Hollyhocks are best planted anytime during the summer or fall. They self-seed easily, which is why they seem like perennials in practice; they’re actually winter annuals. If you plan to collect all the seeds, remember to scatter some on the ground to reseed, because they aren’t perennial; they just look like they are. In my climate, the self-sown seeds tend to germinate in summer if the plants are watered, or in fall if they have to wait for the rain. The seedlings will bloom the next summer, either way.
Hollyhocks are hardy to zone 3, extremely drought tolerant, extremely heat tolerant, and don’t seem to mind moist soil, so they’re appropriate for most climates. Plus they’re pretty!
From my experience so far, I highly recommend black hollyhocks. I originally wanted a rainbow of colors, but now that I’ve tasted several other colors, I’m no longer that interested in them. The black ones seem to have by far the best flavor.
The roots are supposed to be edible and mucilanginous, like okra. I haven’t tried them yet, and I probably won’t get around to it. I’d rather eat the flowers than the roots.
The seeds are supposed to be edible, and that’s something I should get around to trying sometime. Being seeds, they may be a nice protein source, and the plants sure do make a large quantity of seeds. The seeds are big and heavy and pretty quick to winnow clean of all seed pod bits, which makes them quick and easy to gather in bulk.
Given the fact that they’re edible, large, easily winnowed, and moderately brittle, it’s possible they could be powdered and used like a grain. If so, that would make them a really impressively productive “grain” crop. But that’s pure speculation – I haven’t tried anything like that yet.
Has anyone else tried eating hollyhock seeds?
Runs outside to pick petals to dry
) If February is your last frost date, maybe you should direct sow the seeds right away after all, then!