Garden Notes

Camellia sinensis
This white-flowered camellia is the tea plant, Camellia sinensis. Photos by Susan Safford

Cleaning up after Noel

By Abigail Higgins - November 8, 2007

The Nov. 3 gale ruffled quite a few feathers but gave us, thankfully, around three inches of rainfall in return. It caused cancellation of the Martha's Vineyard Agricultural Society's Barnraisers' Ball, which is re-scheduled for tomorrow night from 7:30 to 10 pm.

The debris that rained down is the kind of perfect stuff for adding to compost piles: green and brown leaves mixed with lots of small twigs. It is not going anywhere; all that is needed is the time to rake it up. Seasonal fall tasks, in addition to raking, are liming lawns, fertilizing (with low number organics) beds or individual trees and shrubs, and laying mulch.

When it comes to raking up debris like that caused by the recent blow and making mulch from it, in an ideal world I should like to have something like the following: the biodegradable jute leaf sack, a clever item, shown in issue 130 of "Gardens Illustrated." (Of course, they are expensive and not available around here.) The bags are constructed of jute thread in a very open mesh weave. Fallen leaves are stuffed in tightly and left in some out of the way spot for a year. After that, they become leaf mulch and if the leaves were oak, it is acidic leaf mulch. Take that, you invasive earthworms!

What? I know, I have emphasized to all who read Garden Notes that earthworms are our allies, that they make our lives easier by doing a large part of our work by turning, enriching, and aerating the garden soils we have to work with. (This is all true, by the way.) But an interesting tidbit relative to mulching is contained in the November Avant Gardener on the subject of earthworms: "Woods Not For Worms."

pink-flowered camellia
'Winter's Interlude,' a pink-flowered camellia, blooms in November and December.
Apparently there can be such a thing as a plague of earthworms - yes, invasive species earthworms - and that in forest ecosystems, or acid-loving shrub borders, they can be harmful. In field soils earthworms process organic matter to nourish plants and condition soils; but in woodland soil it is mainly fungi that perform the same function, albeit more slowly, and that is how trees have adapted.

The Avant Gardener: "About a dozen years ago, ecologists studying certain problems in forests in the Northeast traced these problems to the presence and proliferation of some non-native earthworms. The European night crawler, Lumbricus terrestris and an Asian species, Amynthas hawayanus, were decomposing the forest duff...five times as fast as fungi do the job.

"Their activities were releasing nutrients too rapidly and also making the soil too alkaline, causing severe injury to trees, shrubs and perennial plants and killing their seedlings. Rapid duff decomposition was resulting in a bare forest floor or in invasions of weeds such as garlic mustard....

"The USDA regards all earthworms as beneficial, so it is not legal to control them with pesticides. Minimizing applications of non-acid compost and mulches can help, and a promising method being tested maintains worm-discouraging acid conditions with a mix of sulfur pellets and oak leaves mulch."

Camellias for fall bloom

Camellias require acid soil and delight in lots of organic matter. Why should Island gardeners consider camellias? If they consider camellias at all, it is probably as a result of encountering spectacular mature spring-bloomers grown by the late Polly Hill at what is now the Polly Hill Arboretum. Great strides have been made in the hybridizing programs that allow us, in 2007, to plant hardy fall- and spring-bloomers on Martha's Vineyard. Add to that the change in climate, and Island gardeners have enticing reasons to consider camellias.

Camellias, in the family Theaceae, number about 200 species. Of these the most familiar horticulturally is the showy Japanese camellia, C. japonica; but the most familiar of all is the one that we tea drinkers encounter daily, C. sinensis, the tea plant. According to volume 1 of The Botanical Garden, by Roger Phillips and Martyn Rix (Firefly Books, Ontario, 2002, 2 vols.) the family Theaceae is close to the Aquifoliaceae (hollies) and Styracaceae (styrax, etc.) and occurs by streams and rocky hillsides from the eastern Himalayas to Japan and Malaysia.

Camellias have been cultivated for over 1000 years, first for oil from their seeds, later for tea and ornament. In the United States camellias have been thought of primarily as plants for Southern gardens. Exciting developments occurred when the hybridizing work of Dr. William Ackerman of the National Arboretum in crossing the hardier C. oleifera with various C. japonica and C. sasanqua cultivars yielded results. These fall-blooming camellias, mostly with the prefix 'Winter's', are generally smaller-flowered and less showy than their spring-blooming counterparts, but the result is a collection that is hardy up to zone 6 and extends the blooming season of our fall gardens.

Because it already contains hellebores, oakleaf hydrangeas, corylopsis, Cornus alternifolia, ferns and parrotia, the new shade planting at my house requires plenty of acidic mulch. When I received as a present a small potted camellia from the Raulston Arboretum in North Carolina, I had not dwelt much on camellias. But now climate change has become a looming reality and, well - hullo! - I acquired two more fall-blooming ones at an end-of-season sale.

The one pictured with white flowers is the tea plant, Camellia sinensis. It has small white fragrant flowers and for tea purposes is usually grown in hedge-like rows, the tips ("PG Tips" etc.) being carefully pinched off as they grow. In "Manual of Woody Landscape Plants," Michael Dirr cites this plant as one of the great, unsung camellia gems of our hardiness zone and says, "It is distinguishably hardier than [C. japonica and C. sasanqua] and makes a fine 4- to 6-foot high and wide evergreen shrub especially adapted to shady environments.... The plant is not particular about soil or exposure and will perform quite well in full sun." The plant pictured began to bloom in late October and is still covered with flower buds.

The pink-flowered camellia is 'Winter's Interlude,' (zone 6b) an Ackerman hybrid (C. oleifera x C. sp. 'Pink Tea') which produces 3-inch pink anemone-form flowers in November/December and becomes 8 feet tall by 4 1/2 feet wide after 13 years. I have been warned to protect the camellias against deer. I plan to write more about cold-hardy camellias and their culture in a future column.