Anna - lovely order! I do love Brushwood's clematises and Omoshiro is my obvious favorite: now I have three of them but have the feeling I may need more. You make Arabella too tempting!
Betsy - you might want to try adding about 4" of manure at the base, then top it with 4" of the long pine needles or pine mulch and water it well. Clematises thrive on compost so use it, in addition to the manure, if you have it.