Garden Notes: Platycodon

A prized plant for those more problematic spots in the shady garden.

Platycodon supplies a burst of blue to the garden. —Susan Safford

For a month generally known for clear skies and gentle seas, this seems a different July. It is the height of garden pathos to have those early July downpours just when floral magnificence is at its height.

Greenery is less affected by rain. What had been trusses of vibrant roses, heavily flowering hydrangeas and lavenders, container annuals (especially geraniums) fully hitting their stride: all splay or gray out, and many have gone down in piles of brown mush. The damage must be meticulously removed, demonstrating the Achilles heel of garden design that is heavily dependent upon floral display.

The adequate rain has given a semitropical lushness to Island highways and byways, and is good news for the trees in areas hard-hit by caterpillars. Vines and creepers, however, are making rapid growth; scout in hedges and fence lines for strangling plants that are relatively easy to remove while small, but which become major pests once well rooted and established.

Our freedoms: Noise

Over the Fourth there were parades, lovely patriotic bunting, and some inspiring words about our freedoms, all of which stem from the body politic. A seldom-mentioned freedom, freedom from noise, is also essential, and emerges from the health and sanity quarter.

Mechanisms of acute noise-induced stress reactions, as well as long-term increase of stress hormones in animals and humans under chronic noise exposure, have been studied and are well known, particularly pertaining to cardiovascular health. Many who garden do so to counter otherwise unavoidable stresses in life.

Carnival atmosphere or revitalizing one?

Our Island economy (mine certainly) depends on those who come here seeking calm and quiet, and to relax fully, in many cases, in their gardens.

For Martha’s Vineyard to retain its reputation as a sought-after retreat and vacation destination, we must pay greater attention to freedom from noise; and put mufflers on the daily noise assault of low-flying biplanes, mowers, blowers, sirens, and continuously idling or beeping diesel engines or construction equipment. These sources of noise raise everyone’s cortisol levels.

Geese guarding hens

The Essex Farm’s (Essex, NY) Week 28 “Farm Note” mentions the farm’s plans to use Toulouse geese to deter aerial predation of pastured poultry. Speaking of, ahem, freedom from noise: Anyone planning to use geese for this purpose should expect some. Some years ago Allen Healy gave us a pair of Brown Chinese geese, which seem to be protective of the free-range poultry flock here; the tradeoff is their loud honking.

These are wonderful animals, fascinating really. They are among the most regal, intelligent birds, able to recognize friend and foe, see in the dark and tell time, and are possessed of a strong pairing instinct. They clip the lawn, and their eggs are delicious.


Garden fashions come and go, sometimes pale and romantic, other times strongly colored and bold, but blue is sought-after in the garden, year in and year out. The glowing violet-blue of Platycodon grandiflorus is beckoning in Island gardens now.

Platycodon belongs in the Campanulaceae family, joining many other family members that draw us to them visually with their blues and violet-purples. Platycodon is an easy doer, with the caveat that it is not moved. The plant grows with a deep taproot (medicinally important in traditional Asian medicine), and prefers not to be transplanted, inhabiting a bed reliably for years if left alone.

Its ability to flower quite well in low light makes it a prized plant for those more problematic spots in the shady garden. In full sun the plants grow upright and sturdy, although helpfully stiffened by an early-season pinching. In shade expect horizontality, or staking.

There are several forms and colors of platycodon, a single species plant. Nothing quite matches the intensity of the blue forms, but the white of P. grandiflorus ‘Albus’ carries in the evening garden. P. grandiflorus may be had in white, shell pink, or blue flowers and stems growing to about 36 inches, with alternately placed, slight-toothed, oval leaves.

Other forms include blue ‘Komachi’ that remains in the “balloon” form, never completely opening; the more dwarf, heavily blooming strain ‘Mariesii,’ slightly shorter than P. grandiflorus, which self-sows; ‘Sentimental Blue,’ a dwarf form that seems to be short-lived compared to the type; and a double-flowered form, P. grandiflorus ‘Hakone.’

The ‘Mariesii’ plants pictured are heavily in bloom and have not yet been deadheaded, as the large, clearly visible seed capsules show. (Deadheading produces sticky white latex in this and many other members of the Campanulaceae that for some may be a skin irritant.) Collect the deadheaded seedpods and spread where you wish to have eventually — voilà! — a naturally occurring expanse of platycodon.

In the garden

A garden where we work has been plagued by losses of plants due to voles. The perennials have been gradually disappearing, winter and summer, and a number of oakleaf hydrangeas were lost over winter three years ago, their roots gnawed through at the crown level. The owner is very involved in the garden, and heard about peppermint oil’s use to repel house mice. Hoping voles have similar dislikes, we are going to try it.

Lush growth requires more frequent spray applications.

Now is time to sow vegetables for the fall/winter garden: carrots, bush beans, radicchio, peas, and fall/winter cole crops (cabbage, broccoli, broccolini, mizuna). Continue with Bt sprays on them to control caterpillars of white cabbage butterfly. Investigate neem and copper-based sprays for foliar and bacterial problems of cucurbits, tomatoes, and potatoes. Order seed garlic now for best selection.

Take cuttings now for plants of tender annuals you wish to propagate for 2018, such as geraniums (pelargoniums), nasturtiums, plumbago, and fuchsias.

Time to get Fair entries organized. The annual M.V. Agricultural Fair will be held Thursday, August 17, to Sunday, August 20, at the West Tisbury fairgrounds; entry forms are due by Monday, August 14.