SUCCESSFUL GARDENING IN THE NORTH 
CENTRAL REGION 
W. T. COWPERTHWAITE 
Landscape Architect 
Interpreting the Climate and Selecting the Plant Material that Fits 
—Some Surprising Revelations About Temperatures and Rainfall 
PSPBjjllT WAS no fault of the climate 
that f a 'I ure followed the early 
Wj attempts at gardening in this 
ItflOSs region. The older inhabitants 
of the North Central States easily re¬ 
member the time when the outlook on 
both ornamental and economic horti¬ 
culture appeared hopeless. The pio¬ 
neers had tried to follow such accepted 
standards and plants as they had known 
in their homes in East and South, had 
met only failure, and it came generally 
to be thought that nothing very worth 
while would ever be done here. 
Now, happily, we have the proof that 
this North Central section (from Des 
Moines, Iowa, north to Canada and from 
Lake Michigan westward to the Mis¬ 
souri) is really well-adapted to gardening if suitable plant varie¬ 
ties are used with proper cultural methods. 
To meet the Northwest conditions a new horticulture had to 
be developed slowly and through experiment, for there were no 
beaten paths to follow. Success came, however, when gradually 
such varieties as the Patten Greening and Wealthy Apples, the 
Beta Grape, the Latham Raspberry, the Hansen Plums, the 
Zumbra Cherries and other dependable hardy strains of plants 
were developed. These are now bringing great profit and 
enjoyment to Northern planters. 
In the ornamentals the situation was somewhat different, 
for it did not prove necessary to develop new varieties, but 
rather to select, from the older known sorts, those that would 
withstand the climatic conditions. It took years, however, to 
test out these and to determine which sorts were and which were 
not suited. Actual trial alone could solve the problem. 
Climatic Conditions of Violent Variability 
T HERE are certain conditions peculiar to this area, making 
it different from other sections of the country, which may 
be considered as controlling factors. Temperature variation is 
not the whole explanation although that is probably the main 
single element. Visitors from New England always express 
surprise on missing some familiar home plant, saying that it 
gets just as cold in their locality; and references to the United 
States Government Weather Bureau records bear out their 
statement. The mean average annual temperature of St. 
Paul, Minnesota, is 44 0 , while that of Portland, Maine, a point 
practically at the same latitude, ^45.4°. St. Paul has a mean 
average annual rainfall of 27.94 inches as against a rainfall 
of 42.51 inches for Portland. With about the same average 
temperature, the Eastern city appears to have the advantage 
of 15 inches more rainfall per year which is an amount that in 
itself equals the entire year’s rainfall in parts of the Dakotas. 
A comparison of the St. Paul weather reports with those 
from points in other sections will show even greater divergences. 
New York City has a mean average annual rainfall of 44.63 
inches, which is more than one and one-half times that of St. Paul! 
The average annual temperature of New York City is 51.7 0 . 
Going South we find Philadelphia has a slightly warmer tem¬ 
perature of 53.6°, with an average annual rainfall of 41.17 
inches. In St. Louis the temperature is 
averaged for the year at 55.8°, with 
37.20 inches of rainfall, which is con¬ 
siderably less than that along the At¬ 
lantic Coast. These figures, while only 
superficial indices, suggest some of the 
reasons why certain plants do well in 
one locality but not in another. 
The great annual range of tempera¬ 
ture in the North Central States is 
another significant factor. During our 
short hot spells in August, the mercury 
may occasionally register ioo°; and 
there are times in mid-winter when it 
may fall to 30° or 35 0 below zero. These 
temperature changes are often quite 
sudden and are especially noticeable in 
the spring when there are many days of 
alternate thawing and freezing. The winter’s frost enters the 
ground very deeply and in early spring we frequently have 
warm sunshine and balmy breezes which thaw out the surface 
and encourage the leaf and blossom buds to break while the 
plant’s roots are still frozen solid. When a day or two of these 
untimely warmer temperatures is followed by a severe freeze, 
any premature budding is blasted. 
Many plants that blossom early do not take favorably to 
these rapid temperature changes and either grow very poorly, 
or perish. I his freezing and thawing action is naturally a 
very severe strain on shallow-rooted perennials for the “heav¬ 
ing” breaks root connections and may lift out the small plants 
bodily. Unfortunately, and strangely contrary to the ideas of 
our Southern neighbors, we do not always have a heavy pro¬ 
tecting blanket of snow throughout the winter. When the 
snowfall is abundant and lasting, the winter loss, especially of 
the small plants, is greatly lessened. 
General Types of Native Vegetation 
T HE character and disposition of native vegetation in this 
North Central region gives the planter a general basis on 
which to build in making up his planting lists. Roughly, this 
section can be divided into three fairly distinct belts, beginning 
at the north along Lake Superior and going south: (1) the 
Evergreen Forests; (2) the Deciduous Forests; (3) the Prairies. 
Each belt has its characteristic plants, only a few of which seem 
equally at home in all three areas. 
Region No. 1. The northern region, extending south to ap¬ 
proximately half-way between Duluth and St. Paul (about lat¬ 
itude 46), is largely given over to evergreen growth. The 
section is continuous with a like character of plant life in 
Ontario to the north and Northern Wisconsin and upper Michi¬ 
gan on the east. The outstanding trees are the three native 
Pines known as the Jack, White, and Red or Norway. White 
Spruce and Balsam Fir crown the hills and uplands; while 
Black Spruce, Tamarack, and Arborvitae fringe the swamps. 
The deciduous trees are either minor or only temporary factors 
in the vegetation of this region. The quite characteristic shrub 
growth is of Thimbleberry (Rubus parviflorus), Mountain 
Maple, Sweet Fern, Dwarf Birch, High-bush Cranberry, and 
several sorts of Honeysuckle. Here there are also several of 
The region specifically dealt with in this article is in¬ 
dicated by the stippled area above and includes 
six states—Wisconsin, Minnesota, Iowa, Nebraska, 
and the two Dakotas. Many of Mr. Cowperthwaite’s 
conclusions have, of course, a wider applicability 
