Peonies.....you've got peonies?.......in California?
They must be California grown, I thought peonies only grew in northern latitudes where they receive a winter of content....
When a plant, that should bloom, doesn't....then the first thing to do is STOP ALL FEEDING....NO MORE FERTILIZER.
The idea of this is make the plant think---yes, plants think---that they are in distress and whaddya know....they begin to produce buds....in order to produce flowers..which then produces seeds.....and we know what a seed does.

So stop any and all fertilizing until it does bloom.

Plants stop blooming...or wont bloom, for many reasons.
You have to figure out which ones causes yours to not bloom.
Too much water; too much fertilizer; too little water; too high a temperature; too much sun; too little sun' tired out soil; too much shade; too cold at night; too warm at night;.....and it goes on and on.

Sometimes too when a plant just refuses to bud and produce bloom, the first thing you might consider is to divide it.....as we do when perennials like lilies when they stop or bloom small or not as many.
Usually, just dividing the plant makes the plant want to produce more.
Since dividing is easy....make sure each division has at least two 'eyes' and make sure to plant no more than 2" below surface----otherwise, the plant may never bloom.

Now, having said that....maybe that's where your trouble lies....its too deep in the ground.
Bring it up....its easy too, just put a spade into the ground on the four sides....lifting a bit each and then finally lifting the entire plant out and plant it --at the correct depth--in its now home which you have prepared ahead of time.
Water it well, then wait.

What kind of peony did you plant and how big was the root? How many years has it been in place? Do you know the specific name of the one you planted?
I know we have members in CA, trees and Itohs are supposed to do very well there. If that's what you have and you planted a very young one you just might see blooms next spring without doing anything to it. If you planted a large root herbaceous or Itoh there might be a problem, just need more info to try to help. Looking forward to hearing more!

There is no reason to dig up your peony unless you wish to plant it in a better location or plant at a better depth for your location. Inmost ot California they need to be planted so high that the buds for next years stems are visible through the winter. Soil temperature will not provide enough chilling for next years bloom, but air temperature will. I have seen beautiful peonies bloomlng even along the coast when properly planted and cared for. Al

Thank you for the responses.

I don't remember what kind it is (and I'm not finding it in a search) it's a common variety, pink (might be yellow or cream in the center), had a woman's name (I'm thinking Barbara something....might be wrong about that, though). I got it from Home Depot as a tuber.

I've had it for at least five years, it has never bloomed.
I did have it planted in the ground, last year I put it in a container (so I could move it around, thinking maybe it needed more sun). It did produce a couple of flower buds this past spring, but, they didn't open.
The only fertilizer it's had is seaweed/comfrey tea.

I posted here before and was advised that it didn't have a long or cold enough winter to bloom and to dig it up and store it in the refrigerator over the winter.

It does sprout through the winter, but has still never bloomed.
It grows well and the foliage is very attractive so it's not a big deal if it doesn't bloom, and I certainly don't want to risk killing it, but, if I could get it to bloom it would be nice.

I just wonder how deep you have your peony root planted in the ground. Can you see the peony eyes at soil level? I believe that it would help with blooming if you plant the peony eyes shallowly preferably at soil level so that the eyes are exposed. After peonies bloom (when temps are hot if your peonies do not bloom), you should put a layer of mulch over to protect them from the heat and sun. When fall comes around, pull of the mulch and expose the eyes again.

Here is more info that may help you to troubleshoot from Charmarron Peonies Garden

Why Do Peonies Fail To Bloom?

There are many reasons, but here are the most common:

Plants are too young and immature. Let them develop.
Plants are planted too deep. In California plant top root eyes at or slightly above soil level.
Large clumps planted without proper division. Dig, divide into small or standard divisions and plant.
Plants have too much competition from surrounding trees and shrubs.
Plants have too much shade which encourages tall leafy plants and no blooms. Peonies need full sun or at least 6 hours of sun a day.
Too much nitrogen was applied which encourages foliage not flowers. Phosphorous or potassium will strengthen roots.
Plants are undernourished. Buds show, but do not develop. Fertilize to add strength.
Buds killed by late frost.
Excessively hot weather. Late, full double varieties often fail from this cause.
Buds attacked by thrips will turn brown and fall. Spray to prevent this.
Ground is too dry. Water down to the bottom of roots.
Roots infected with nematodes or root-knot. Destroy.

Thank you everyone :)

I just checked it and it's sprouting already. A couple of the tubers are above soil level, but most are below, so I'll remove some of the soil to expose them.

Must be nice to see things sprouting already! Do you expect more very cold weather that would kill new growth or is this really when you see things start to grow there? My ground is so frozen I couldn't get the stakes in to secure Christmas decorations--I have to go out and pick up my deer a couple of times a week! Can't wait for spring.... At least wintersowing will start in a few weeks for me so I'll have something to do rather than just stare at all of the snow....

I don't claim to be an expert on peonies, but I do have an experience with a similar problem here in Southwestern Ohio. My mother had a huge beautiful peony plant that has bloomed for years and then bought two others. They grew for a few years and never bloomed. They would get buds but they would not open. We noticed one day that the one that was a faithful bloomer had ants all over its buds and the two that budded but didn't bloom did not have the ants. We figured that maybe the ants were important so I bent over buds from the faithful bloomer with an ants on it and touched the other plants' buds that had never opened. The ants crawled onto the new plants and from that year on they have bloomed faithfully without any coaxing from us. Coincidence? Maybe, but I say it may be worth a try before you disturb them from their bed, because that will be a twice a year job that you may not have to do. My mother never touches her peonies. They take care of themselves which she appreciates. Also it seems to me that if the short dormancy period was a problem, it wouldn't get its buds in the first place. Good luck!