I would make sure the seed you purchase for next season is listed as bulb forming if that is what you want. AS you are aware, not all fennel forms a bulb.

Look for Florence Fennel. The package should show a bulb.

Well, unfortunately, the package was labelled Florence Fennel AND the artwork showed a bulb, as well as the written description referring to a bulb. The seed company, Botanical Interests, did not respond to my query.

It sounds like your fennels bolted, otherwise they sould not have flowered and seeded. Whe root plants bolt(onions, carrots, etc) the spend their energu on seed production.

Probably it had been too warm. Fennels, parsley,.. are generally cool crops and will bolt in hot/warm weather.
Try planting them earlier next time.

Tomtuxman,
Sounds like you do have the right kind of fennel. I've only grown fennel for two seasons, so I'm no expert, but I had a similar experience as you with the two-dimensional bulbs. They didn't round out like the ones I buy at the market, they were quite flat.

The first time I grew it, one plant out of four went straight to seed. My understanding is that once they start to bolt they need to be harvested ASAP, as they bulbs are likely to become tough and tasteless. I kept the first one to flower because fennel flowers provide lots of pollen for beneficial insects, and then I harvested the seed, so it wasn't such a bust after all.

The other three plants lasted long enough to make flattish bulbs a little bigger than my fist, and then showed signs of bolting (bulb starting to elongate, thick stem coming out of the middle), so I picked them. They were OK, but probably not as tasty as the fennel bulbs I buy.

The second year I planted in the autumn rather than spring. No bolting, but I wound up wanting the space for something else, so I picked the bulbs very small and used them in salad. Again, nothing to write home about in terms of flavour.

I've read in various books and websites that florence fennel is hard to grow well because a) it's subject to bolting and b) you have to get the watering just right to get good flavour and good bulb formation.

I'm going to give it one last try next autumn/winter. I might also look for seeds from a different source, maybe from an Italian seed company. Here in Australia we don't seem to be able to get named cultivars, it's all just labelled 'florence fennel', but there may well be varietal differences in bulb shape/quality. I'd like to find out how the commercial growers grow the stuff, and where they source their seed.

Anyway, best of luck with your fennel, sorry I can't be more helpful.

Tracey

I've no side by side garden comparisions of my own to prove this....but....I've heard that transplanted fennel is more likely to bolt than seed that is directly sown. Also, if you do need to use transplants, use small young plants, not ones that have been in small pots for too long. This applies to other plants, too. I've definitely found it is true with cilantro.

Last year I only had direct sown fennel. Most bulbed up. This year I used the same seed and started plants indoors and set them out when they were quite small. Some bulbed, some bolted. Not sure if it was weather and timing or the transplanting that made the difference

.
First of all what you describe ie; flat, fan shape is indeed Florence Fennel. I personally don't buy seeds from Botanical Interests even though they are available at nu merous locations in S.CA.
Earlier today I drove to "Trader Joe's" by LAX and stopped at Armstrong's Nursery because they carry this CO.'s seeds.
Their package says Florence. Finocchio. This is either a mix of both types or they don't know. The watercolour rendering on this packet is rather primative but does clearly suggest Finocchio and bnot Florence.
I only grow this plant in the Fall early winter Oct-Feb.
I also harvest when they the bulbs are 4-5 inches acrossed at base.Any that get bigger than this I leave to produce .I really prefer the taste of Florence over Finocchio.

zebraman,
it's been my understanding that finocchio is the italian term for florence fennel aka sweet fennel aka bulb fennel. It's definitely used that way here (Aust).

Does finocchio in the USA denote a particular variety of bulb fennel? I'm curious about how it's different.

Hey Ausbirch ; I have grown both cultivars. Florence is flat with a distinct fan shape and space between each leaf base. Finoccio produces a solid base with no space between leaf/stem bases.Not fan shaped like the illustration on the cover of "Botanical Interests" seed packet.The artist's rendering is clearly depicting Finoccio and not Florence. However the english description above the latin name clearly states Florence, Finoccio. If yhey were both synonymous then this would be redundant.

The latin name for Florence Fennel is (Foeniculum vulgare dulce).

That's even more confusing, then, because the original post refers to Foenicucum vulgare var. azoricum, not Foenicucum vulgare var. dulce!

I'd like to revive this post. I'm trying to figure out which fennel is the bulbing fennel that Baker Creek sells. They list "Di Firenze Fennel" as the "The authentic "Finocchio"", with a picture that has fan-type leaves.

Then they list "Florence Fennel", and describe it as: "(Foeniculum vulgare) Plant grows like dill." They do not have a picture.

Which actually bulbs?

Here is a link that might be useful: Baker Creek Fennel

I find that curious. Firenze is Florence in Italian--at least as far as the city is called... I am also having trouble understanding the product descriptions for bulbing fennel at various seed companies.

I also failed a few times in Michigan, same symptoms as the OP, and the bulbs I see in farmer markets are also pitiful. I suspect that the continental US is not a good place for finocchio (Florence fennel). It is a winter vegetable in its native range, and it may need the gentler temperature variations of the Mediterranean. The stalks, ground with the food processor and mixed with salt and spices, make a decent stuffing for whole roast chicken. If I ever move to California I will try it again, otherwise I am through with it.

Imagine my surprise that this thread has been revived. I must revise my earlier response post -- Botanical Interests did indeed eventually respond to my query/complaint: they sent replacement seed packet (same variety) plus additional comps. This coming growing season should be interesting.

Although I originally suspected the wrong seed variety, I have come also to question several other factors in my lack of bulbing success: (1) soil chemistry. I had similar bad luck with kohlrabi not "bulbing", and someone recommended I add bonemeal. (2) generally lousy growing weather in the Northeast last Summer -- cool, way too much rain.

BTW, I did not have a problem with early bolting as some responders suggested. And I both direct-sowed as well as had transplants that were started quite ealy indoors.

I will believe it is possible when I see a locally grown, large, fat bulb, similar in size to those you find in stores. So far, me, my gardening buddy, and two or three guys selling at farmer markets all got miserable thingies.