An orchard of stone fruits thrives in the Maine foothills

THE orchard lies on a gentle slope among the foothills of the White Mountains, which push over from New Hampshire into this region of Maine. On this clear, early fall afternoon, the outlook is as beautiful as any you will find in a state that has more than its share of scenic beauty. Even so, it is the orchard and its owner, Roland E. Decoteau, that command our complete attention on this occasion. Orchards are commonplace in Maine -- apple, pear, and blueberries for the most part. But this one is different. By Maine's standards the fruits Mr. Decoteau grows are exotic -- peaches, plums, apricots, cherries, and others. According to conventional wisdom, many of the stone fruits, as they are called, are not expected to survive, let alone do well, this far north. Yet the trees on this 11/2 acres of southwest-facing hillside are thriving, including a Santa Rosa plum, normally successful only in a temp erate climate zone.

Word of Decoteau's success this far north has spread as far as the Soviet Union. Fruit tree specialists from around the United States stop by, often unexpectedly, and the orchard is now an official test site of both the New York State Fruit Testing Cooperative and Canada's Western Ontario Fruit Testing Association. Decoteau's name is now included on the germ plasm inventory of the US Department of Agriculture, and it was here, Decoteau presumes, that Soviet fruit specialists came across his name. In any

event, a letter arrived from the USSR not long ago requesting scion wood -- cuttings used in grafting.

Decoteau's career was spent largely as an auditor for the Internal Revenue Service, followed by 10 years as a high school history teacher. He had always gardened and grown some fruit in his yard here, but it never entered his head that he would ever become a grower of any consequence or the focus of so much attention. What changed it all was a trip with his wife, Ruth, to California's Sacramento Valley in the mid-1960s. That's when he picked and ate apricots fresh from the tree for the first time and at e, as he recalls, ``more apricot pie than my wife thought was good for me.''

On returning to Paris Hill, as his neighborhood is known, Decoteau planted his first apricot. Now he has 35 varieties in his orchard, including Tilton, a variety bred to withstand the heat of the San Joaquin Valley in California, yet which also withstands the cold of this Maine hillside. He also began including the other stone fruits in his orchard. Many are experimental, numbered but as yet unnamed, and will remain that way until they prove themselves in nationwide trials. One is a cross between a plum

and a cherry, and another, he says, is a plum-apricot cross.

The Santa Rosa is one of this world's more flavor-filled and aromatic plums. It is native to the warmer regions of Japan and thrives in Australia, South Africa, and southern California. It isn't recommended for home gardens in the United States much farther north than Maryland. Yet here it is in Maine, and doing very well. The one fruit I was given to try was not quite so richly flavored as those from a tree in warmer climes, but it was a sweet, good-tasting plum just the same.

How does Decoteau succeed in a region where few such trees are expected to survive? To start with, his orchard has a set of conditons that make it milder than average for the region. He also takes a couple of steps -- white-painted tree trunks and a sod cover -- to improve the advantages that come with the topography.

Since the Decoteau orchard slopes toward the southwest (directly south is best of all), like a solar house it absorbs more of the sun's heat over the year than does a flat site and vastly more than a site that slopes toward the north. This means that the soil warms up earlier in the spring and cools down more slowly in the fall. The same slope also protects the trees to some degree from the intense cold of north winds during winter.

Most important of all, however, is the good air drainage a sloping site such as his provides. On a winter night heavy cold air, like water, drains into the valleys, where it forms ``lakes'' of cold. Not for nothing does the first frost form in the valleys and the first deep freeze take place there, too. Only after these lower valley regions fill up with cold air do really cold temperatures start working back up the hill.

Cold damage in an orchard is not just the arrival of cold temperatures but the frequency of these arrivals and the length of their stay. Obviously a hillside such as Decoteau's is less frequently affected by the bitter cold.

Major damage to fruit trees can also occur when the winter sun strikes the exposed south-facing side of the trunks. The dark bark absorbs a considerable amount of heat, compared with the shaded parts of the tree. In winter this temperature differential can cause the warmer side to expand and rupture, eventually killing the tree.

There is a simple measure to prevent this type of damage: Paint the tree trunk with white latex (not oil-based) paint. The white surface reflects away enough of the incoming radiant heat to prevent this uneven expansion and consequent rupturing of the bark.

Decoteau keeps his orchard under sod, the grass growing right up to the base of the trunks. He does this for ease of maintenance (``I simply mow the orchard every couple of weeks,'' he says), but he believes it may contribute to his orchard's winter health as well by providing a mass of organic matter (roots and surface debris) which cushions soil temperatures and prevents the freeze-thaw cycle that causes frost heaves and damage to tree root systems.

Having a thick sod cover, however, requires another tactic each spring when the trees are fed a 10-10-10 fertilizer. The grass competes with the trees for soil nutrients, and simply broadcasting the fertilizer would give the grass a field day. It would absorb most of the nutrients before they got to the tree roots. So Decoteau punches holes in the earth near the drip line of the tree and fills these with the fertilizer. This gets the nutrients down to the roots. Job's tree spikes (rigid plugs of fertili zer that are hammered into the soil) also work well in sod, he says.

The point Decoteau stresses to those who visit his orchard is this: Not everyone can simply start growing stone fruits in Maine or other northern climes. But a good many people do enjoy favorable microclimates, perhaps without knowing it. Even the south-facing wall of a house or garage can provide the right climate for one or two trees. Better still is an L-shaped or V-shaped house with the hook side facing the sun.

I know of at least one Vermont gardener who built himself a special ``fruit house'' -- a light shed with an all-glass front that faced the sun. It was by no means a greenhouse that stayed above freezing, but it did moderate the temperatures enough for half a dozen peach and plum trees to produce all the fruit the gardener's family and a few close friends could eat.