The acorn looking things are seed pods, I think. But they are not ready to harvest until they turn completely brown.
I tried to make a picture from my hibiscus, which is setting a lot of seed pods right now. These are no where close to being ready to pick. Take a look.

Once they are brown and ripe, you can plant them. But I don't know what zone you are in. If you have enough time left for them to germinate and get several leaves they might survive the winter. I have planted seeds in pots in the fall,and left them on my porch and had germination in the early spring.

Glenda

Here is a link that might be useful:

Sorry to bump an old thread, but my hibiscus (Luna Red) is not setting seeds. I get the pods like in the picture, but where the pod should be is a tiny (1/4 inch) acorn shaped node. Is it just not getting pollinated? Thanks.

Probably that is the case. I didn't get any seed pods last year when it was so dry here, so maybe there's not enough water?

Glenda

It's been a couple of weeks. I'm getting more rain than normal and lots of flowers, but still no seed pods. The flowers on the Luna Red and the Turn of the Century open for a day, maybe two depending on the temperature, than fall off leaving no seed pod. I'm wondering if they can even set seed since they are both hybrids.

I suppose I can do divisions in the spring?

Glenda,

A friend recently gave me seeds of the large red flowered Hibiscus plant and I would like to start them. Would it be best to place them in a rooting medium or right in soil within a pot? I have never had luck previously so maybe I was doing something wrong. Thanks. Vicki

Divisions in the spring are easy to do, and I've always had good luck with them.

I pot my seeds in soil in a pot. I usually use at least a gallon pot, it is surprising how fast they grow from seed in that first season.

Good luck to you.

Starting Hibiscus seeds.

1. Tear off a piece of Aluminum foil about 1'X 1'
2. Obtain a white paper towel.
3. Obtain a piece of 120-grit sandpaper.
4. Take one seed at a time and run across sandpaper
several times in same place and set aside. Do this for
as many seeds you want to start.
5. Lay aluminum foil flat on table.
6. Fold paper towel in half twice.
7. Wet paper towel generously.
8. Set towel in center of foil.
9. Place sanded seeds in center of wet paper towel.

10. Fold wet paper towel in from both sides covering seeds.
11. Fold foil from both long sides then ends to cover paper
    towel completely to block out light.
12. Set the seeds on top of something like a Satellite
    receiver for 2 or 3 days. Temperature stays Constant.
13. Germination should have taken place (I have 99%
    germination rate by this method.)
14. Fill 3" peat moss cups with potting soil.
15. Generously moisten soil.
16. Plant 3 seeds per 3" peat moss cup spaced evenly apart.
    There should be a new start (root) protruding from seed,
    plant the new shoot (root) down and rest of seed under
    ¼" of soil.
17. I use plastic containers that 5 or 6 pound bulk
    hamburger comes in. (Washed out of course)you should be
    able to place 9- 3" wet cups in this plastic container.
18. Keep in dark warm area of house until they pop up.
19. Place in sunny area (south window)
20. Keep moist(can pour water into plastic container
    which will water from bottom.