My first attempt with cardoon was a semi failure. I grew it successfully but the dang stuff wasn't edible. Too bitter. Yuk.
Ok, Hawaii isn't the ideal location for it. At least my place isn't. I'm told that I'm too warm at night. Others have told me that cardoon should have decreasing light when harvested, that meaning, November/December. Yet others have said that it needs to be blanched. There's nothing I can do about the warm night temps, but I can change my planting time so that the crop matures in late fall/ early winter. And I can blanch it.
Above is a photo of the first blanching experiment. One of the community gardeners wrapped cardboard around the harvestable central parts, hoping to keep most of the sunlight out. We will try leaving it on for a month to month & a half before trying a harvest again. In the meantime the plants will be fertilized and kept moist so that they keep growing.
In a couple of weeks I'll give you an update after we sample the next harvest.