Gurneys and Johnny's have them.

I recommend Debruyn seeds. Best price you will find with good quality and service. You will love Purple passion. Produces thick but very tender spears.

Debruyn seed - asparagus

ETA: They are located in Michigan and they ship at the proper planting time for your area which is sometime in late April for zone 5b probably.

Thanks!

much of michigan has ground freeze .. and frankly it doesnt matter when you want them.. if the ground is frozen ... you get them when they can be properly dug ..

in the alternative.. a larger operation.. would have dug them in fall.. and stored them in basically refrigerated warehouse .. for shipping in spring.... it just depends on how large an operation the seller is ..

it seems to me.. many of the listed vendors above.. are actually all one company.. someone bought them all up a while back.. of i dreamed that.. im not sure anymore .. maybe gardens alive or something like that.. anyone ha e more current info???

ken

Johnny's has Purple Passion but you have to buy 25 at least ... https://www.johnnyseeds.com/vegetables/asparagus/purple-passion-f1-asparagus-crowns-2225.html

Urban Farmer has them in groups of 10 ... https://www.ufseeds.com/product/purple-passion-f1-asparagus-roots/ASPPR.html

Debruyn has the best deal by far, worth serious consideration

I'm not sure who owns who, a lot of these older companies have been taken over by a few companies, which are very hit or miss with roots, bulbs, woody stems. You might get lucky, but they will charge you even if they do not have proper stock of what they list. Also prices can vary wildly with some companies depending on which "sale" code they give you.

Pinetree has purple asparagus. They're in Maine...

https://www.superseeds.com/collections/asparagus

Fedcoseeds.com has Purple Passion Asparagus crowns. They're also in Maine.