GUIDE TO SERENDIPITY
TAKING EDITORIAL CONTROL

An old wicker chair woven with Geranium psilostemon ‘Ann Folkard’ rises through a spring haze of bronze fennel (Foeniculum vulgare ‘Purpureum’) and forget-me-not (Myosotis sylvatica).

It can be hard to get used to letting the wind blow and the garden grow. When self-sowers, which have little regard for group-picture rules, plant themselves where they’re likely to thrive, you might find a 4-foot-tall flowering tobacco growing in the front row with the impatiens or at the very edge of a walkway. But that doesn’t mean it has to stay there. Even in loosely designed naturalistic gardens we will want to preserve certain views and keep paths open and welcoming. Gardeners can encourage rowdy creativity while still taking disciplinary action when and wherever necessary. We are in charge. Move seedlings where you wish while they’re young, and pluck out mature plants that have grown in the way: easy come, easy go. We might also allow a few to stand out here and there in unexpected places for the sake of spontaneous and uncontrived informality.

Seedlings that come up in the garden give us a unique opportunity to make design decisions after seeing what works and what doesn’t. We are released from the pre-planting obligation of visualizing all of the variables that make placement a puzzle (such as where they will receive the light, water, and soil fertility they require, and look their best in combination with other plants) because as volunteers, they plant themselves. I let some of them grow long enough to see if I approve. If a plant doesn’t contribute to the beauty of a view, or if it has happened to land where the chance of a healthy maturity is low, I move or remove it.

In the meantime, before decisions need to be made, it’s worth letting thickly sown carpets of seedlings function as weed-defying groundcovers. Bronze fennel (Foeniculum vulgare ‘Purpureum’) and forget-me-not (Myosotis sylvatica) each create a fog-like layer in May that may be encouraged to float through beds before the fennel lifts skyward and the forget-me-not goes to seed. Allow deep burgundy shiso (Perilla frutescens var. crispa) seedlings to roll a red carpet under the roses or alongside sage in the herb garden. Cut the seedlings back as they grow to prolong the illusion, or pluck them out, leaving some standing in strategic spots for next year. Biennial seedlings like common teasel (Dipsacus fullonum) which won’t flower until its second season, may function as a groundcover for the entire first season. As the garden fills in and makes their barrier less necessary, remove any plants whose flowers won’t be required for next year’s design.

ABOVE LEFT Common teasel (Dipsacus fullonum) seedlings may be left as a weed barrier until you’re ready to plant something else in their spot. They’ll send up flowers the following year. ABOVE RIGHT After editing, only a few teasel are left to bloom this year.

Here it must be acknowledged that most gardeners are sentimental plant lovers who find it almost impossible to throw anything healthy and attractive on the compost heap—even when facing more than we and the pollinators could possibly want. But when it comes to weeds, we’re coldhearted killers. Whenever I have trouble letting go, I remind myself that weeds and self-sowers have a lot in common when they are in the wrong place. Rather than letting unwanted plants spoil your opinion of any species that’s perfectly lovely in small doses, choose to be the best editor your garden has ever had. If you’re ever unsure whether a volunteer should stay or go, stand back, close one eye, and hold your thumb out over the plant in limbo like an artist critiquing a composition. If you liked the view better with it, it stays. If not, out it comes.

The soft-hearted option of transplanting seedlings instead of composting them is available when they are still young. Use your imagination to predict where you won’t want them to grow and then exercise your creative muscles by designing them into different beds or combinations instead. Or donate some to friends and plant sales. The smaller they are, even if they’re taprooted or resentful of disturbance, the more likely they will be to survive the move and thrive in their new digs.

To transplant whole patches of seedlings, slide a trowel or spade deeply underneath, capturing plenty of soil with the roots and taking care to keep their root systems as intact as possible. Then pot them up to give away or replant immediately. After relocation, keep seedlings watered while they become established as if you had paid top dollar at the nursery. Thin them if necessary once they have taken hold, either by cutting some off at the ground or by pulling some out (if you can do so without unearthing the whole bunch).

Besides transplanting, another excellent way to get a self-sower established in a different part of the garden is to collect and scatter its seeds, or lay a ripening seedhead down on a new patch of ground, and cross your fingers for its debut in that spot next year.

Laying the groundwork for seeds

Mulching the garden suppresses weeds, conserves moisture, and insulates root systems over the winter. Certain types of mulch also add organic matter to the soil. But when we garden with volunteers (which requires a leap of faith that seeds will, in fact, germinate), success often hinges on providing a good patch of soil for them to land on—that means go easy on the mulch.

An alternative to mulching heavily for weed suppression and moisture conservation, is to grow more plants. A chock-a-block garden and an attentive gardener will be much prettier and do a better job than any mulch in keeping weeds from taking over. Also, the more plants you have shading the bare bits (provided it’s not a maple tree or willow) the more moisture retentive the soil will be.

But the happy medium in any garden, intensively planted or not, is a fine-textured mulch that covers the soil without smothering it. A condo-dwelling friend once lamented that forget-me-not refused to take hold in her foundation bed, which was buried at the condo board’s insistence under 2 inches of bark mulch. Most seeds have a hard time finding traction in that stuff and it is toxic to some seedlings. But I’ve seen plenty of volunteers wend their way up through shredded leaves, pine needles, buckwheat hulls, and pea stone. Seeds just have to be able to locate some soil under the mulch and see a little light too.

Sweet William catchfly (Silene armeria) on the move; unplanted from where it wasn’t wanted, on its way to where it’s needed.

Fall is a good time to apply mulch and/or compost to suppress weeds that would otherwise sprout during a warm spell, add organic matter to the soil, and provide insulation to protect shallow-rooted plants from frost heaving. Biennial seedlings will have already germinated, so make sure you don’t carpet over them. Annual seeds will be fine tucked under a light layer of mulch for the winter and will find their own way out come spring. If you use a heavy mulch as a protective winter blanket, pull it off the beds in the spring to allow the soil to warm (insulation slows heat transfer in both directions) and give your favorite volunteers a chance to germinate.

Help conserve soil moisture during the summer by spreading another light layer of mulch over exposed soil in early summer after the self-sowers have emerged and you have finished planting. Resist the urge to disturb the soil around your favorite volunteers and, as insurance, save some of their seeds to start yourself.

Forget-me-not (Myosotis sylvatica) seedlings germinate through buckwheat hull mulch, which is lightweight and elegant—but expensive.