Anyone know when people start selling avocado scion wood?
Avocados go through periodic vegetative flush, root/fruit development, and flowering phases, but the exact timing of those varies a lot between cultivars and even in different climates (CA vs FL, e.g.) for the same cultivars. Scions can be taken any time
other than when flowering is about to begin or already underway, and even then it probably will be fine. Shortly after fruit set is probably the best time, but really any time small/immature vegetative buds are visible on the firm green wood. Sorry if that doesn't really answer the question, but I think the answer is probably "it depends on the type of avocado you want and where the seller is growing it."