Learning to Make the Best Use of Climate

PREFACE

For the reader's convenience this chapter is divided into four parts, representing the major climatic regions of the 48 adjoining states. Each part was written by an author within the region and familiar with its climatic variations. The regions are the Northwest, Northeast, Southwest, and Southeast.

Gardening generally requires a mild, sunny climate with adequate moisture. However, if you consider terrain features which favorably influence the immediate climate, you may be able to garden locally in a seemingly unlikely area for this activity. An attempt is made here to explain climate in the United States and its use to gardeners.

Temperature and rainfall are probably the two climatic features that gardeners first worry about. Sunshine, average cloud cover, and wind also are important. Adequate moisture is absolutely necessary, but if all other climatic features are suitable for gardening in an area, water may be supplied by some irrigation method. Thus, natural rainfall is not necessarily among the most critical points when looking for a gardening location.

A gardener needs to thoroughly understand the term "growing season." The true growing season is determined not by climate alone but by climate plus the climatic tolerance of a specific crop. The number of frost-free days does not really describe a growing season length because most vegetables and fruits have a certain amount of tolerance for a temperature of 32 F. Some species even have a temperature tolerance lower than the freezing point of water.

Soils are a reflection of climate because they develop and improve naturally as climate acts upon the parent material. Where climate is suitable for successful gardening, soils generally are acceptable.

Four large, general gardening climate regions exist in 48 adjoining States. Texas, with its great breadth and elevation variations, lies in 2 regions.

Climate is involved in crop quality. High temperature hastens ripening and reduces quality. Sugar content increases in maturing crops during sunny, cool, dry weather. Coloring is also increased under sunny, cool days and clear cool nights. Rapid ripening rates of sweet corn, under extremely hot weather, may reduce the harvest period to half the usual length. Extended warm, wet weather produces fruit that is soft, watery, has low sugar content, and needs special attention in storage and processing.

Climate influences disease and insect development. Warm, wet periods activate leaf blights, scab, bacterial disease, and fruit rots. Insect build-up occurs under hot, dry conditions. Cool-dry, and cool-moist periods will suppress disease and insect problems respectively.

Understanding the local climate, and learning to plan with the weather, are vital preliminaries to successful gardening.

IN THE NORTHWEST

by Earl M. Bates.

Earl M. Bates is Advisory Agricultural Meteorologist, National Weather Service, Corvallis, Oreg.

The Northwest region has widely varied terrain. Although much of the region is mountainous and lies as far north as 49 latitude, gardening can be profitable and pleasurable.

Two principal climate types are a marine climate west of the Cascade Mountains of Washington and Oregon and a continental climate east of the Cascades, through the northern Rocky Mountains and into the northern plains.

The marine climate is characterized by a mild, wet winter and only a moderately warm, dry summer. A considerable amount of summer cloudiness prevails, which reduces the sunshine.

This area has a long frost-free season, but spring is frequently too cool and wet for early planting. Therefore, the effective growing season is relatively short. Gardens are practical here, but the vegetables selected should generally be the "cool season" type. Peas, carrots and cole crops do well, but such species as corn and tomatoes are practical only in certain warmer valleys.

Crops grown in the area may be either those requiring much or little water because even though the summer is dry, gardeners can feel confident of enough irrigation water for all crops.

In the continental area from the Cascade Mountains eastward to the northern prairie States, climate varies considerably due to elevation.

In the mountain valleys from Washington and Oregon eastward through the Rockies, gardening is usually successful at elevations at or below 1,500 feet above sea level.

Across the northern prairie States gardening is done at even higher elevations because large amounts of sunshine and stirring of the air by the plains winds have a favorable influence on this spring climate. However, late frosts occur in the northernmost tier of States, and the frost-free season may be as little as 130 to 140 days in places.

East of the Rockies, gardens of the hardier vegetables can be grown. Such species as corn, tomatoes and melons require special care and only the experienced gardener is likely to have success.

From the Cascades eastward through the Rockies and into the northern plains, rainfall is generally less than adequate for a garden. Irrigation water seems to be no problem at today's population level and probably will not be for at least a few decades. Sunshine is abundant across this region and provides for fast growth.