Plant Hardiness, Climate & Soil Conditions in the US States

It is important to understand in detail the climatic conditions and soil conditions in your region to be able to get the best results in your garden

Plant Hardiness Zones

Plant Hardiness Zones (PHZ) in the United States are determined by the average minimum winter temperature in a given location.

The map is divided into 10-degree F zones, with Zone 1 being the coldest and Zone 11 being the warmest. 

For example, Zone 5 has an average minimum winter temperature of -20 to -10 degrees F, while Zone 9 has an average minimum winter temperature of 20 to 30 degrees F.

The PHZ map is used by gardeners and growers to select plants that are likely to survive the winter in a given location.

It is also used by farmers and agriculturalists to choose crops that will be hardy enough to withstand the cold temperatures in their area.

In general, plants that are native to North America are more likely to be hardy in all parts of the country than plants that are native to other parts of the world.

This is because North American plants have evolved over thousands of years to deal with the continent’s wide range of climates and weather conditions.

There are some exceptions to this rule, however.

For example, cacti and succulents from desert regions are not typically hardy in areas with cold winters.

Likewise, tropical plants from rainforests will not usually survive in temperate zones with freezing temperatures.

When choosing plants for your garden or farm, it is important to consider the plant’s natural habitat and decide if it is likely to be able to adapt to the climate where you live.

If you’re not sure about a particular plant’s hardiness, it’s always best to err on the side of caution and choose a different species that is known to be more tolerant of colder temperatures.

Here is more information on the Zones –

Soil Types and Importance

Soil is the thin layer of material that covers the Earth’s surface.

It is composed of rock, minerals, organic matter, water, and air. Soil provides a medium for plant growth, filters water, stores nutrients, and supports wildlife.

The United States is a big country with many different types of landscapes and climates.

This means that there are also many different types of soils.

The composition of soils varies depending on the parent material it came from, the climate, the amount of organic matter in the soil, and how long it has been forming.

Soils are constantly changing, but very slowly. There are three main types of soils in the United States: sand, silt, and clay.

The proportions of these particles determine whether a soil is classified as sandy, silty, or clayey. A fourth type of soil, loam, is a mix of all three particle sizes. 

The percentages of sand, silt, and clay in soils across the United States vary widely.

In general, sandy soils are found in drier areas with low rainfall, while clayey soils are found in wetter areas with high rainfall. Silty soils are somewhere in between.

Soil composition is important for farmers and gardeners because it affects how well plants can grow in a particular area.

Different plants have different needs in terms of the amount of water and nutrients they require from the soil.

Knowing the composition of your soil can help you choose plants that are more likely to thrive.

If you’re interested in learning more about the soil in your area, there are many resources available online and at your local library.

The United States Department of Agriculture (USDA) Natural Resources Conservation Service (NRCS) has a Soil Survey that you can use to find out more about the soils in your area.

Soil Orders in the USA

There are 12 soil orders in the United States:

Entisols, Inceptisols, Alfisols, Spodosols, Andisols, Oxisols, Ultisols, Mollisols, Histosols, Aridisols, Gelisols, and Vertisols. Each soil order has different characteristics that make it unique.

Entisols are young soils that have not yet developed horizons (layers). They are found in areas of recent geological activity such as volcanoes or glaciers.

Inceptisols are also young soils that have weakly developed horizons. They are found in humid forested areas where organic matter has begun to accumulate.

Alfisol is an older soil with well-developed horizons. They are found in temperate forested areas and have a high clay content.

Spodosols have very little organic matter and are found in cold Forested areas such as Scandinavia and Canada.

Andisols have high concentrations of volcanic materials and are found in tropical regions near active volcanoes.

Oxisols have very little organic matter and high iron content. They are found in hot dry climates such as deserts.

Ultisols have low fertility due to the leaching of nutrients from the horizon layers. They are commonly found in the Southeastern United States.

Mollisols have a high organic matter content and are some of the most productive agricultural soils in the world. They are found in temperate grassland regions such as the Great Plains of the United States.

Histosols were once classified as mucks or peats but have since been re-classified due to their unique characteristics. They are made up mostly of decomposed plant material and can be found in wetland areas such as bogs and swamps.

Aridisols have little or no organic matter and develop hard crusts when dry. They are common in desert regions where rainfall is low, and evaporation is high.

Gelisols have permafrost within two meters of the surface limiting plant growth. They are found in Arctic tundra regions where temperatures remain below freezing for extended periods of time.

Vertisols shape when wet but crack when dry due to their high clay content. They occur naturally in flood plains but can also be created by irrigation.

Soil types differ based on their location, climate, parent material, age, and biota.

Knowing the soil type is important for predicting how an area will respond to disturbance, what kind of plants will grow there, and what sort of management practices need to be used to maintain productivity.

Here is a detailed video based on soil surveys –

Plant Hardiness Map, Climate & Soil Conditions for the Various US States

Here are quick guides on soil, hardiness zones, and climatic conditions for various US states –