Question
I planted jackmanii last season, but am now realizing that I know very little (next to nothing) about caring, pruning, etc for these gorgeous vines! Can you please just give me the general info? Things such as pruning (when,how) fertilizing, and any other pertinent information? If 齩u can help, my clematis, my grandma, and especially myself will be forever grateful.

Thanks a million,
EricG

Answer
Jackmanii is one of my all-time favorite Clematis; I have one growing up our lamp-post/address marker in front of our house!  Great choice.  In terms of overall care, clematis live by the rule of "cool feet/warm head."  What that means is that they like their roots to remain cool and moist (not waterlogged) and they want their "tops" to get plenty of sun.  I typically plant perennials around the perimeter of the clematis roots (not crowding it, of course), so when the perennials leaf out in spring, they'll shade the clematis' root ball and lower growth.  Now, pruning is key.  Jackmanii belong to what's called "Group 3" of the Clematis family; this group likes to be pruned in late winter/early spring, generally around the time the forsythia blooms and/or when you or your neighbors fertilize your roses. (I'm not sure what Zone you're in, but that seems to be a good rule of thumb...)  Prune back hard, to about 6" off the ground, making sure that you leave several leaf "nodes" from which the vine will branch and grow.  Once the vine gets to be about 18" tall, it will need staking or support on whatever type of structure you're using, whether it's a trellis, tree, post, old car, your in-laws, whatever.  At the end of the season, I tie the vine up and just tuck in down behind the structure.  I know some gardeners who prune it back in November with no ill effects, but so far I haven't been that gutsy.   One way to enjoy the blossoms is to clip one or two off right at the blossom's base, and float it in a pretty shallow glass bowl with some floating tea candles.  Makes a lovely centerpiece for a spring/early summer dinner.  Good luck with your Jackmanii, and enjoy the show!