For future reference you can just tack these additional questions on to your previous posts and it bumps them right back up to the top. No need to start a new one each time. That way all of your questions and the answers given are tied together and we don't have to search out the previous questions or rehash previously given info. As to the mix, only soil-less potting mixes are recommended for containers no matter what you are growing in them. No regular garden soil, no Miracle Grow brand Garden Soil only MG Potting Mix, no potting soil and no regular top soil. All of those compact far too much, do not drain effectively in containers, and cause root root. You'll also find any number of recommendations for potting mixes over on the Container gardening forum here. As to eventually planting them in straight clay soil? I can't help you with that as I don't have clay. Can only say that from all I have read, those that have to deal with heavy clay soil don't seem to find it good for growing much of anything. The Soil Forum here has many discussions on how to amend clay soils so that they can be used for planting so you might want to do some reading over on that forum too. Dave PS: I am curious as to why you want to shade these since chokes are full sun lovers?

I've had good luck vernalizing young Imperial Star artichoke plants in the refrigerator in past years. I think it's more reliable than leaving it up to Mother Nature, at least in Michigan's variable (wierd!) climate. I do it when they have about 6 leaves and are about 4 inches tall. If all went well, I got them sown on time (early March), germination was prompt, etc., it should now be early/mid May. I let them get a little on the dry side but not wilted, since moisture is the enemy in this operation. I like to dust the foliage of each plant with a little Gold Bond type medicated body powder -- the zinc oxide and plant essential oils are fungicidal -- be sure to get some down into the crown of the plant. Then, I wrap each transplant individually (note, no pot on these, I grow them in cell trays and just pull them from the cells) in a paper towel or napkin, and pack them into a big ziplock bag. Then, seal it up. This goes in the bottom of the fridge for 10-14 days. During this time, they will turn somewhat yellow, they will curve up in response to gravity, and when they come out, will look kind of sad. But, as long as they are kept reasonably dry, they won't rot and dry. It is a GOOD IDEA to pull them out every few days and inspect, so that you don't have a nasty surprise of rotten plants at the end of this process. If rot does start, pull off the damaged leaves, dust with more Gold Bond, and repack in fresh, dry paper towels. You could probably save some of the little packs of silica gel from clothing, shoes, electronics to throw into the ziplock to help control the moisture during this vernalization. After the 10 days minimum, pull them out, repot them into about 4 inch pots, water them well, and stick them in the shade for 24 hours to recover. Then, I put them in the greenhouse and really baby them for a few weeks. At this point, it's probably mid June, about Flag Day, and they need to go into really rich, well-drained, well prepared ground or very large containers (the rope-handled utility tubs are a great size and are relatively cheap and durable as planters). They like a lot of fertilizer and water (but not soggy soil, or they'll rot). You should start seeing blossom initiation in mid/late July or early August, and will get artichokes into October. This has worked for me in the past. Hope this helps.

What variety is it? If they weren't exposed to chilling temperatures sufficiently in spring, it's possible they are confused and will not produce this year. The varieties for home production should be chilled in spring by exposure to temps. below 50 degrees for 10 days or so, to trick them into thinking they've gone through a winter.

My artichokes did the same thing!! but after a long time (so long, I had actually forgotten about them) I noticed that they look like they are trying to come back with a few leaves popping up now, they were very very slow to grow from seed and didn't seem to grow much at all for a very long time. I will be interested in others opinions on this too. I had a similiar thing happen with onions grown from seed. I guess it's very possible that because they are so small that they can get cooked from the heat?