Garden Notes: Think long-term

Gardening can lead to better environmental habits.


Spring, beginning officially with the Vernal Equinox, March 20, is when outdoor activities resume. With that very much in mind, what better time to focus concern on our surroundings?

Growing awareness 

Growers and gardeners tend to have good environmental habits, and yet, ironically, our sector (the so-called Green Industry) is heavily intertwined with plastics use. Everyone recognizes plastics’ advantages, but they also extract a heavy toll on environment and health wherever they are manufactured, used, or dumped. (

Thoughtful Island gardeners and Green Industry are urged to re-use, recycle, and dispose of plastics with care and intention.

Our surroundings

I have never seen so much trash and litter along Island roadsides. What is happening? We are becoming like the mainland.

Also like the mainland: We are losing our night sky. Massachusetts and its towns have bylaws regulating light pollution. Here, they seem to be casually enforced. Why?

“The increased and widespread use of artificial light at night is not only impairing our view of the universe, it is adversely affecting our environment, our safety, our energy consumption, and our health.” (The International Dark-Sky Association,

Longer-term thinking

For many, gardening is a threshold activity, one that leads to eye-opening experiences in the natural world and the earth we live upon. For others, based upon the well-stocked pesticide and herbicide aisles, gardening remains stuck in “kill-and-control.”

This year, with storms, heat and drought on minds more than ever, we can give our environment top billing along with our own health and gardens, and rethink some old-fashioned gardening “rules.” Eco-gardening really is a thing!

If we want to increase environmental awareness in our activities and practice eco-gardening, then much of what we did as gardeners was counterproductive.

A small example: cleaning the woods, à la suburbia, makes life a struggle for wildlife. The rotten white oak stump (pictured) is peppered with holes made by woodpeckers hunting insects. The drilling speeds decomposition of the wood, to become humus on the woodland floor. Dead and fallen trees provide valuable habitat for wildlife we love, such as owls, tree nesting birds, and bats.

Tree canopy

While development pressure is busily reducing the Island’s tree canopy, other places, which have lost it, are working hard to replace and restore it. In Portugal on March 21, World Tree or Forest Day is celebrated by — you guessed it — planting trees, especially to remediate areas devitalized by mining and other activities.

A unique, traditional Portuguese agroforestry system, known as Montado, based on several beautiful oak species, is used in management of the understory, ranging from forest systems (cork in cork oak systems) to agrosilvopastoral systems (cork, sweet acorns, animal and/or crop production together). Also, about 4,1400 hectares of low-density stands of economically important sweet chestnut (Castanea sativa) exist, called “Soutos e castinçais.” To learn more, link to

A similar system is Bocage, described on Wikipedia as “a terrain of mixed woodland and pasture characteristic of parts of Northern France, Southern England, Ireland, the Netherlands, and Northern Germany, in regions where pastoral farming is the dominant land use.”

Rhododendrons on basic soils?

An article by nurseryman David Rankin in the January issue of The Garden, “Why Grow Rhodos?” was interesting. His thesis: that ericaceous and acid-loving plants, such as rhododendrons, camellias, and hydrangeas may be successfully grown on basic soils, despite evidence and conventional wisdom that thus grown plants invariably suffer from chlorosis and poor growth.

It is assumed that our hydrangeas reliably flower blue and that Island soils are acidic; likewise, that rhododendrons invariably flourish in them. (This, it turns out, is not always the case, as evidenced by numerous plaintive queries for advice to blue-up hydrangea flowers.)

However, the acidic soil rule has now been tentatively contradicted. Observation and experiments have shown that unhealthy cultivated plants suffer from manganese deficiency, while foliage of healthy plants contains much more, up to 50 times more. The hypothesis is that, in wild populations on limestone soils, leaves from healthy plants drop to form mulch that acts as a slow release fertilizer. “Once a healthy population is established, it becomes largely self-sustaining, recycling its manganese.”

To test that these plants would flourish, the experimenters first added chelated manganese to foliar sprays. They eventually decided fertilizing with ferrous sulphate and manganese sulphate was cheaper and sufficient to maintain plants. “Fallen leaves should never be removed, but left to decay under the plants.” Those interested might try this themselves.

Garden connoisseurs

The better informed gardeners are, the better stocked our Island garden centers become. If gardeners do not know them, plants will not sell; only a few of the choice plants are stocked, if there is low interest.

Polly Hill described her frustration that there was such a limited choice here (“every year, the same twenty-five ‘tried & true’ plants!”), when she first started Island gardening and planting. She had to start propagating herself — not a bad idea — to acquire the wide and diverse array of plants she suspected would grow well.

When you encounter a plant you like, note the botanical and cultivar name, so you can research it. Visit public gardens. Read plant tags. Read gardening books. Check online resources. Knowledgeable gardeners make great garden center customers.

In the garden

Set up functional composting systems. Cut down last year’s perennial debris, if left for wildlife. Prune back Group 2 clematis, leaving two sets of strong buds on stems; cut Clematis paniculata to bases. Prune roses: remove discolored stems and prune to outward facing buds. Prune rose of Sharon and PeeGee hydrangeas if desired, but leave Hydrangea macrophylla for now. Correct snow and ice damage.

Check undersides of seedlings for whitefly and spider mite. Insecticidal soap controls them. Re-seal half-full seed packets and store cool, dry, and dark. Cutworms turn up in early spring when soil is cultivated.


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