The blazing blue Lithodora


I suspect quite a few islanders, heading into Oak Bluffs on New York Avenue, nearly ran off the road when the blazing blue plants trailing over the retaining wall came into view. For those who would like to know more about this over-the-top cobalt blue splash, the plant is Lithodora diffusa, in the family famous for other blues, the Boraginaceae.

Formerly not reliably hardy here and grown as a special, tender perennial (i. e. annual), lithodora in Island gardens now does much better with the milder, drier winters, provided its cultural requirements are met. If the requirement for perfect drainage can be fulfilled, lithodora is listed as hardy from zones 5-9.

Success with lithodora is contingent upon well drained, neutral to acidic soil, and preferably a warm, sunny aspect: it is a perfect rock garden subject. (National web sites recommending sun to partial shade for this plant do not apply for Island conditions.)

Damp, freezing conditions may cause blackening of the plants’ leaves. Creating good drainage for the plant would be an added insurance policy against this happening. Try planting with some pea stone in the bottom of the planting hole and mulching with a layer of it around the plant, for the foliage to cover as it grows and to prevent its contacting soil.

Should lithodora suffer damage, shear back the blackened portion. Shearing back may also be done in late June after the first flush of bloom to keep the plants at a low, mounding height.

There are a limited number of lithodora cultivars; plants available here are likely to be “Grace Ward” or “Heavenly Blue.” The difference between them is hard to tell. An all-white form is mentioned, “White Swan,” and Blooms of Bressingham has introduced a cultivar with a white central star, “White Star.”

Value of garden visits

Recent hours spent in Charles Cresson’s Swarthmore garden, Hedgeleigh Spring, were stimulating for me, as a gardener who does not leave the Island often, and as someone who sees too many of the usual plants and plant combinations, and not enough of the choicer ones. I see my own pedestrian work and not enough of the innovations and creative work of other gardeners.

Vignettes from Hedgeleigh Spring:

In-ground, hardy pomegranate faced down with Asphodeline lutea; arborized rhododendrons under-planted with epimediums; yellow pansies spiked with small red annual salvias, backed by Rosa moyesii ‘Geranium’ leaning over the nearby fence; Astilbe chinensis var. pumila as groundcover; the trio of brown/purple bearded iris with airy pink-flowered heuchera and sprawling lavender campanula in front. Whatever it is that catches one’s eye elsewhere influences one’s own potential for better gardening.

Tour: five stunning up-Island gardens

On Saturday, from 11 am to 4 pm, May 26th, three gardens in Chilmark and two in West Tisbury will be open, each uniquely designed and developed by their owners. All proceeds benefit the preservation efforts of The First Congregational Church of West Tisbury.

David Geiger’s landscaping expertise was recently featured in the Spring/Summer issue of MV Magazine, which has also featured “Nina Schneider’s Garden,” now owned and maintained by Holly and Jim Coyne of Virginia and West Tisbury.

Trudy Taylor presents an oceanside approach within the context of a natural environment and native plantings. Peter Norris is developing an extensive woodland setting with species rhododendrons, azaleas, ponds, and damp gardens planted with ferns and epimediums. Susan Leland has been creating, planting, and maintaining garden paths surrounding her home, with colorful trees, shrubs, bulbs, herbs, and perennials, for over 20 years. This will be her debut tour. Refreshments will be offered in a poolside setting. Tickets are $25 and are available in the church office, Heather Gardens, Vineyard Gardens, and Middletown Nursery. They make wonderful Mother’s Day or birthday gifts.

The craft of pruning

I have carefully saved the concise, mimeographed pruning hand-out by Louisa Hill Spotswood to refer to from time to time. Its advice continues to be succinct and useful, such as “Pull back hair”; “Use good sharp tools”; “Make cuts where you can see what you are doing.” It is astonishing how I need to be reminded to sharpen my tools!

Louisa’s paragraph “Intent” provides an outline of goals: “What are you aiming for?”

To repair damage.

Containment, to keep a plant from outgrowing its situation, or from interfering with another plant.

To reach the flowers (as with lilacs).

To encourage flower and/or fruit production.

To rejuvenate.

To bring order and elegance to a messy plant.

This week, the Rule of June 30 (to maximize the blooming of shrubs) is especially apt: “If it blooms before June 30th, prune right after flowering. If it blooms after June 30th, prune in winter or early spring.”

An easy to remember, handy rule for pruning large-flowered hybrid clematis (from the garden tip of the week, 4/4/12 Telegraph UK): “Any clematis that flowers between midsummer’s day [June 21] and September should be cut back hard now. Pruning instructions are always on the pot tags: so keep them in a safe place.” This advice is slightly late for 2012 but worth noting and scribbling down somewhere.

Cut back spring flowering shrubs, such as forsythia and fragrant viburnums. Doing it now, before next year’s flower buds form, prevents destroying them by later pruning. Take out up to one third of the old canes, right down to the ground, to preserve the plants’ typical habit, and avoid clipping the tops, unless you prefer the hedged look.


Homegrown has its last meeting at Agricultural Hall for the season on Sunday, May 20th, from 4 to 6 pm. The June meeting will be at a member’s garden, to be decided. Please plan to bring your surplus plants, cuttings, and seeds for sharing with the group.