The great big thread of sunchoke info - growing, storing, eating/recipes, science facts

Hi, fellow growers up north, I am curious if your sunchokes bloom before first frost? If not, is the shortening of day length and cooler temperature sufficient to trigger tuber bulking? Mine just done flowering and the tuber will start to fill and plants gradually die back the following month.  Christopher's sunchokes don't seem to bloom yet. Is there a variety difference for planting in high latitude area?

I'll add that when you mix varieties in one patch they will fight for dominance. They are allelopathic, which means they spread chemicals that retard competitors, even other varieties. That means they will not grow to their best. That's also true when they're crowded without being mixed. I have a patch of two mixed varieties and discovered this the wrong way. In separate patches the varieties grow better, nothing stupendous, but clearly noticeable. I've also cut flowers from sections of patches for wine and there's no difference in yield between the deadheaded and the fully flowered plants.
I use a sod/garden fork to dig with. I've thought of making a shaker frame with 1' screen to help separate the tubers but just haven't gotten around to it. I've heard of small potato pickers modified for the smaller tubers that are pulled behind garden tractors. I don't grow enough to warrant that expense, plus the picker will only go so deep.
I wait for the tops to die and fully dry before harvest, that's when all the nutrients in the tops drain into the tubers making them their largest and full flavored. I got a small electric chipper and while I'm harvesting I chip the stalks and spread them over the patches, mixing in most of the chips as I dig. That's built up the soil very well. Yearly digging, yearly amending and mulching the tops loosens the soil very well. Yeah, sand will compress amazingly tight and hard, that's how sandstone is made.
Harvest as thoroughly as you want, it's very-very unlikely you'll take too many tubers as any tiny ones and roof nodules will sprout again.
I'm in west-central PA., zone 5. I harvest from when the stalks are dead until the ground freezes, then early in the spring I harvest more as soon as the ground thaws. Also, downwind of the Lakes I've got moderate to high humidity. That promotes powdery mildew which can be exaggerated by the plants growing too crowded, restricting air flow. Unless the powdery mildew gets too stout, it doesn't hurt the plants.
Keep digging, mulching and amending the soil and it'll loosen up.

May,
There are some varieties that seldom bloom, even when in full sun. Mine are in full sun and bloom every year, however, I have a tiny patch planted in the shade of a Maple that seldom bloom. Full sun makes a difference on blooming with nearly all varieties.
Side note: The Colonials sent Sunchokes all over the world from the early 1600s on and today there are over 400 recognized varieties. A friend in Tasmania remembers her mother cooking them when she was a child. They'll nearly all handle zones 3 through 8 but there are some that take zone 2. Those are usually found in northern Canada and northern European countries.
I had one variety that grew 12'+ tall and spread way over 4' underground. They were a white/tan skinned smooth tuber like carrots in size and shape. They were, however so obnoxiously turnipy/herbal flavored that one tuber chunked into a large soup pot nearly overpowered the soup. I got rid of them. They do not all taste alike! I've collected mine locally in west-central PA, near the heart of their native range and where people have these tall, beautiful, yellow flowers in their yards and flower gardens that they don't have a clue what they've actually got.
It's best to find varieties that are known to grow well in your climate, but it's also OK to try any you can get your hands on. There are varieties that mature in just over 100 days and others that take over 150 days. I only have two types now and they mature three weeks apart. That gives us a tad bit more time in the fall to harvest. Some types spread tubers over 6' and others that spread only around 16" and clump in an easy to pull gob!
The early type seldom has flowers that last until first frost, but the second type lasts well after first frost and the flowers and leaves are hard frost hardy, barely wilting. I do not harvest based on frost but only when the tops die and fully dry, just like harvesting potatoes. Potatoes and Sunchokes can be very bitter if harvested too early.