Starting in Style
Talking Plants Tips for Planting Clematis
We begin. The following are non-negotiable if you want to grow great clematis:
- Good to great drainage.
- Amended planting hole.
- New plants cut back by half.
- Cool root run.
- Know your zone.
Good to Great Drainage
No doubt you already know if you've got it (if not, dig a hole, fill it with water, see how fast the water seeps down. If it just sits there, don't even think of clematis). If it's merely adequate, you can put a couple inches of quarter-minus gravel at the base of the planting hole, plus amend the soil with grit or more gravel. If you have clay soil, don't use sand. Sand + Clay = Brick! If your drainage is just fine, thank you, don't do a thing.
Amended Planting Hole
Trusting your soil's already light (or been lightened), remove it from the planting hole (which you've dug as deep as the pot and at least three times as wide). Throw it in a big pot and mix it with garden compost (Maurice Horn suggests a 50-50 mix). Doesn't matter what kind of garden compost -- your own, store-bought, rotted manure, worm castings -- just be sure it's not potting soil compost. They're easy to confuse.
New Plants Cut Back By Half
This is the truly gruesome part. And here's the reason you do this: to divert energy away from the top growth and force it back into the roots, and create a stronger, healthier, more luscious and ultimately, more vigorous plant. You've only got to do this for the first two years if yours is a large-flowered hybrid; make that only one year if you're planting the more exuberant, small-flowered species (like my Clematis alpina 'Willy'). Special dispensation: If you've bought a plant already in flower, enjoy the blooms in the pot. Then once they're finished, get out those clippers, cut above the leaf node, and plant it.
Cool Root Run
You hear the old adage, ad nauseam: head in sun, feet in shade. It's all true. The ground around your clematis needs to be nice and cool. The easiest way to do that is to put the plant in shade, and help the vine scramble up to the sun. Another option is to plant within the shade of another plant; my 'Willy' is on the north side of the crape myrtle he will soon climb. You can also tuck your clematis in with a blanket of small, non-invasive perennials. The point is, don't let the base of your clematis bake in the sun.
Clematis are what we call "heavy feeders." The large-flowered hybrids are particularly piggy.
Maurice Horn recommends either a once-every-three month application of a granular, slow-release fertilizer ("a hailstorm's worth"), or monthly application of over-the-counter tomato food (it's slightly higher in potash), spring through summer/early fall. Don't fertilize after September, as the clematis needs to harden off for winter. The small-flowered hybrids are less maintenance, plenty happy with just one spring feed (or an annual topdressing of composted manure; no clematis would turn that down).
Know Your Zone
While a number of clematis are incredibly cold-hardy (and grow well in Alaska), those same plants -- however much you crave them -- will be wretched in the Southeast. No use knocking your head against the wall with clematis types that are fundamentally ill-adapted to your climate and your soil. That may mean doing a little research before plopping down $18 or more on an irresistibly flowered vine (just because it's offered by a nursery, particularly if that nursery is an all-purpose big box store, doesn't guarantee it's right for where you live). If you're really into it, find out whom that clematis's Daddy is (i.e., the species that are in its parentage), to determine where it's native and what it enjoys. And if you're hardiness Z5 or below, be sure you plant the crown of your clematis at least 2" below ground.
And for those of you who've made it this far, here's your...
Believe it or not, you can actually bury your clematis up to its lowest leaf node -- even if there's a foot of vine before the first leaf! Your reward: a bigger beefier plant that will undoubtedly have more than one stem, which is the final, ultimate, hidden key to the perfect clematis vine.
Listening to audio requires the RealAudio
Copyright © 2003 National Public Radio, Washington, D.C.