Made in the Shade: Tips from the Experts

Margaret Roach at last weekend’s shade gardening workshop, above

LAST WEEKEND, along with a few dozen other garden nerds, I attended a half-day shade gardening workshop in Columbia County, and took 8 pages of notes.

We started at Margaret Roach’s lovely, hilly two-acre spread (she being the garden blogger I most admire, and author of a forthcoming dropout memoir about leaving the city for a more serene life in the sticks — I can relate). Our second stop was Loomis Creek, a nursery known for unusual offerings and stunning display borders. One of Loomis Creek’s owners, Bob Hyland, presented the second half of the workshop, and shared the news that the nursery will be closing for good Columbus Day weekend, when Bob and his partner de-camp for new adventures on the West Coast. Great bargains there in their final close-out; I came away with a car-full.

When asked why we were there, one woman spoke for many: “Because I don’t have any SUN!!!” Despite what I hoped when I first came to my Long Island cottage in May ’09 — south-facing backyard and all that — I have NO full sun anywhere on my half-acre. It varies from part to deep shade throughout, and I’ve been gravitating toward plants that don’t have to struggle. Also, almost all my gardening knowledge to date comes from books. I wanted to see how real gardeners actually handle plants (I may never plant a quart nursery pot again without tearing it into several pieces, as we watched Bob Hyland do with a  pot of ajuga).

Here’s some of what we learned last Saturday, beyond the basics (the basics being ‘plant in multiples of 3,5,7,9; in drifts or waves rather than rows…’):

• Shade plants grow slowly. That’s why they tend to be more expensive. It takes a nursery 2-3 years to nurture seedlings (hellebores, epimedium) along to salable size.
• When transplanting/dividing plants in fall, pre-soak the ground. I’d always just sprinkled perfunctorily, but Margaret recommended a few hours a day for a few days in advance. And wait for cool, overcast weather to do the deed, if possible.
• September is THE time to transplant and divide perennials (in Zone 5, anyway; here in Zone 7, we can probably go into October). October’s the month for planting new trees and shrubs.
• A lot of woodland (shade) plants have shallow root structures, so their roots freeze easily if you move them too late. They are adapted to live in small pockets of soil between tree roots. “Pocket planting of baby seedlings may be more effective,” said Margaret, than buying larger nursery specimens. “It’s nature way.” That requires patience, not my strong suit.
• Think “opportunistic” gardening on a shady property — that is, create gardens for beauty in March through May, before deciduous trees leaf out. Identify your seasonal opportunities and make the most of them.
• An easy kind of shade garden (well, it’s all relative) is creating a “skirt” around deciduous trees, with early bulbs and primulas, trilliums, Jeffersonia, and ‘dolls eyes’ aceta (cimicifuga) — none of which I’ve tried — especially near the house, where you can view them through a window in March and April.
• The best way to design: “Look out the window.” Especially in winter, that’ll be your most frequent vantage point.
• Group containers full of high-impact, long-lasting plants, such as ‘citronelle’ heuchera, hostas, begonias, and hakonechloa to welcome visitors into a shade garden.
• Spanish bluebells are “good for the back 40” – sweeps of ground cover visible from a distance.
• Note to self: get some petasites! They’re dramatic, huge-leafed, pre-historic-looking things.
• If you want to special-order annuals from a nursery for next year — if you need a large quantity or want something unusual — do it now.

The Aegopodium Avenger

LAST YEAR IT WAS WISTERIA VINE that was the bane of my gardening existence. The stuff was so out of control it had taken down a shed and killed trees by strangulation. Hired landscapers hacked down much of it; I pulled and cut many trash bags full; and in late fall, my daughter and I applied Round-Up to the cut ends of sprouting wisteria with surgical precision. Though we didn’t eradicate it completely, the situation is much improved.

This year it’s goutweed, or aegopodium podagraria, a super-invasive groundcover that, left to its own devices, would take over the entire backyard, that’s driving me crazy. I have huge sheets of it in several areas. I tackled one of them yesterday, on hands and knees, using a claw tool to pull up as much as I  could of the roots, feeling like a prisoner trying to dig his way out of jail with a teaspoon.

What makes goutweed so pernicious is that it spreads three ways. First, by underground rhizomes, or horizontally running roots a few inches under the surface. It also puts down taproots, like dandelion, and it seeds in late season, below.

It’s practically unkillable, according to contributors to the forum on Dave’s Garden, a very useful site for all things plant-related. “Aegopodium laughs at Round-Up,” one person wrote, and indeed, mine did (see the pitiful results of my spritzing, below).

Once I’ve removed all I can of the root (it can re-sprout from any tiny piece you may miss), I cover the bare soil with cardboard and old rugs, below (porous landscape fabric isn’t good enough, apparently). Soon I’ll put a thick layer of leaves or wood chips on top. And if anything dares to re-sprout, which I’m sure it will, I’ll hit it again with the more concentrated form of Round-Up. Sadly, when it comes to aegopodium, organic solutions just don’t cut it.

I’m pretty sure that both the wisteria and the goutweed were originally planted as ornamentals, perhaps thirty years ago — the goutweed possibly as the prettier, variegated bishop’s weed, which then reverted to all-green and ran amok during years of neglect.

Weed-killing is a nasty business, but it’s got to be done — if you want a garden, that is, and I do. Lucky I don’t have a day job.