The Garden in May: Selective Weeding of Garden Volunteers

Some of the garden’s most striking scenes are the result of selective weeding of volunteers, plants that show up each year with little effort on the gardener’s part. Such self-sowing annuals and biennials will become permanent residents of your garden, but only if you get them started by scattering their seed. Examples include Shirley poppies (Papaver rhoeas), mullein (Verbascum thapsus), calendulas (Calendula sp.), pansies (Viola sp.), nasturtiums (Tropaeolum majus), and meadow hawkweed (Hieracium caespitosum).

Shirley Poppies

Self-sown Shirley poppies favor the vegetable garden with their translucent petals and unique seed pods.

Self-sown Shirley poppies favor the vegetable garden with their translucent petals and unique seed pods.

Several autumns ago Marjorie scattered a handful of tiny Shirley poppy seeds, a gift from the garden of a friend, in a small corner of a perennial bed. The seeds germinated the following spring and the resulting plants grew to three feet in height, slender stems clad with blue-green leaves. In July, each stem was topped with a blossom, a single row of pink petals with the texture of crinkled tissue paper.

These first plants scattered their own seed and the following spring there were poppy seedlings growing throughout the garden, easy to recognize by their unique foliage. Most were weeded out, a few allowed to grow and blossom.

A honeybee coming in for a landing.

A honeybee coming in for a landing.

These poppies have been with us every summer since, growing among the strawberries, winding through the branches of blueberry shrubs, circling the compost bin. And there are still poppies in the corner of the perennial bed.

Throughout the summer day, these few poppies are among the first plants to catch the eye as you stroll through the garden. I have been in the garden at first light to watch the poppies greet the day, to see them swaying with the slightest breeze, the low-angled light casting stamen-shadows inside curved petals. At dusk the flowers glow, reluctant to give up the last rays of sunlight.

We do not know the variety name of these Shirley poppies – or corn poppies – which move about the garden from year to year. They are descendants of the wild red corn poppies immortalized in Canadian John McRae’s poem written during World War I: “In Flanders’ Fields the poppies blow, between the crosses row on row”. They were named in honor of the vicar of the parish of Shirley in England, the Reverend William Wilks, who discovered a variant of the local field poppy with a narrow white border around the petals. With careful selection and hybridization over many years, he obtained a strain of poppies ranging in color from white and pale lilac to pink and red. Further selection has given rise to semi-double and double forms, as well as flowers with a ring of contrasting color around the edge, a picotee form.

Shirley poppies are the only flowers in Marjorie’s Garden that attract honeybees. This may be because the poppies appear in their relative abundance as a field of pollen-bearing flowers, always the preference for foraging honeybees, or perhaps it is the size of each flower, large enough to accommodate several workers at once. Luckily for a gardener afflicted with an allergy to their venom, the honeybees are too preoccupied with their work to feel threatened, even when I brush against a flower.

Mullein

A mullein plant is a woolly mammoth with stout spikes of yellow flowers that open sequentially, bottom to top.

A mullein plant is a woolly mammoth with stout spikes of yellow flowers that open sequentially, bottom to top.

We don’t know the origin of the mullein in Marjorie’s garden, but each May we begin culling out most of the volunteer seedlings. Only a few are allowed to continue growing vegetatively through their first summer, waiting to flower until the following year. Such is the nature of biennials.

Unlike the slender poppy, a mullein plant in its second summer is a six-feet-tall woolly mammoth. Densely hairy frost-green leaves clasp the lower two-thirds of the main stem, those nearest the ground more than a foot in length. The upper third of the stem develops into a stout spike of one-inch yellow flowers that open sequentially, bottom to top.

Although a single mullein plant can produce over 150,000 seeds, only a few will germinate and even fewer will make it to the second year. Mullein seedlings are not strong competitors, thriving only in the margins of the garden and along the bed edges. In a typical summer we have a few flowering plants on the edge of the strawberry beds where they stand in strong contrast to the creeping berry plants, and a few selected first-year plants scattered around the vegetable and small fruit beds. Their flowers bring native bees and other pollinators to the garden; their late-summer seed heads will bring goldfinches. On summer mornings the large felted leaves covered with dew are an arresting sight.

Calendula

Solitary bees forage for nectar on the calendulas in Marjorie's Garden.

Solitary bees forage for nectar on the calendulas in Marjorie’s Garden.

This self-sowing annual grows in drifts and patches throughout our vegetable garden, its orange and yellow flowers serving as magnets for native bees. Every few years, when the seedling populations seem sparse, we scatter a few fresh seeds along bed edges, but in most years there are more than enough volunteers popping up everywhere. Calendulas are easy to transplant if you need them somewhere else in the garden.

Violas (pansies)

We always grow pansies in pots on the porch railings. Despite efforts to keep them

Violas became naturalized in Marjorie's Garden from seeds produced on potted plants.

Violas became naturalized in Marjorie’s Garden from seeds produced on potted plants.

floriferous by snipping off fading blooms, a few seed pods ripen on these plants, the seeds winding up in the beds beneath the porch. Each May, new seedlings appear in these beds beneath the spreading arms of elderberry shrubs, and, as the season progresses, these self-sown pansies bloom in colors totally unlike their parents. Volunteer pansies also populate the vegetable garden, introduced from the compost pile.

Nasturtiums

One year I placed pots of nasturtium among the vegetables to create a moveable feast for bumblebees. The

A volunteer nasturtium in the onion patch.

A volunteer nasturtium in the onion patch.

following year, nasturtium seedling were popping up in beds where the pots had rested, evidence that their seeds can survive the winter. Yet there are years when there are no self-sown nasturtiums and we have to start with pots again. Perhaps winter survival of seeds is dependent on depth of snow cover.

Meadow Hawkweed

I selectively weed meadow hawkweed, leaving some to flower on the fringes of the garden, even though I know it to be a non-native invasive weed in pastures of the western U.S. I didn’t plant the hawkweeds

Yellow-flowering meadow hawkweed volunteers make perfect companions for nearby catmint.

Yellow-flowering meadow hawkweed volunteers make perfect companions for nearby catmint.

in Marjorie’s Garden, they were there before there was a garden. I manage them in the same manner that I manage their cousins, the dandelions. And for the same reason: native bees forage them.

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About Reeser Manley

I was born in Laramie Wyoming but moved to the southeast at an early age. I was educated through my B.S. in Biology in the Columbus, Georgia area, then crossed the Chattahoochee River to earn my M.S. in Botany at Auburn University. For the next ten years, I worked as Horticultural Manager for the George W. Park Seed Co. in Greenwood, S.C. At 40 years of age, I decided to return to graduate school and in 1994, I earned a Ph.D. in Horticultural Science from Washington State University, Pullman, Washington. Fast forward through 10 years at university (7 at UMaine, Orono) and you find me teaching high school science in Eastport, Maine, the edge of the world, and writing a weekly garden column for the Bangor Daily News. My new book, The New England Gardener's Year, a Month-by-Month Guide for Maine, New Hampshire, Vermont, Massachusetts, Rhode Island, Connecticut, and Upstate New York”, will be published later this year by Cadent Publishing. You can learn more about the book by visiting its Facebook page: http://www.facebook.com/pages/The-New-England-Gardeners-Year/187285218055676.)