what planting zone is boise id

Understanding Boise, Idaho’s Planting Zone

Boise, Idaho, generally falls within USDA plant hardiness zone 6b and 7a. This means the average minimum winter temperature in Boise ranges from -5°F to 10°F, impacting which plants can survive the winter.

What is a Planting Zone?

Planting zones, often referred to as hardiness zones, are geographically defined areas that categorize regions based on their average annual minimum winter temperatures. The USDA (United States Department of Agriculture) developed a system of these zones, numbered from 1a (coldest) to 13b (warmest). Each zone represents a 10°F range. Knowing your planting zone helps you select plants that are most likely to thrive in your area, as they are adapted to withstand the typical winter cold.

Boise’s Specific Planting Zones: 6b and 7a

Boise, Idaho, is located in a transitional zone, with most of the city classified as either zone 6b or 7a. Zone 6b has an average minimum winter temperature of -5°F to 0°F, while zone 7a experiences temperatures between 0°F and 5°F. The specific zone within Boise can vary depending on elevation, microclimates, and proximity to the Boise River. Areas closer to the foothills might experience slightly colder temperatures, potentially pushing them towards the 6b range. Conversely, more sheltered areas within the valley may fall more firmly into the 7a category.

Why Knowing Your Planting Zone Matters

Choosing plants suitable for your zone is crucial for successful gardening. Plants that are not hardy enough for your zone may suffer frost damage, die back, or not survive the winter at all. Selecting plants rated for zone 6 or 7 (and sometimes even zone 5 with proper winter protection) increases the likelihood of them flourishing in Boise’s climate. Conversely, plants adapted to warmer zones (like zone 8 or higher) are unlikely to survive the winter in Boise without significant protection.

Factors Influencing Plant Survival in Boise

While planting zones are a valuable guide, other factors play a role in plant survival. These include:

• Microclimates: Even within a small area, variations in sunlight, wind exposure, and soil drainage can create microclimates that affect plant hardiness.
• Soil Type: Boise’s soil is typically alkaline and can be heavy clay in some areas. Amending the soil with organic matter improves drainage and nutrient availability.
• Water Availability: Boise’s arid climate requires regular watering, especially during the hot summer months.
• Sun Exposure: Different plants have different sun requirements. Choose plants that are suited to the amount of sunlight your garden receives.
• Snow Cover: Snow can actually insulate plants and protect them from extreme cold, making plants hardier than their zone might indicate.

Resources for Identifying Plants for Zone 6b and 7a

Many online resources, local nurseries, and gardening books provide information on plants suitable for zones 6b and 7a. Look for plants labeled as “hardy to zone 6” or “hardy to zone 7” to ensure they can withstand Boise’s winter temperatures. You can also explore USDA Plant Hardiness Zone Map from Wikipedia.

Frequently Asked Questions

What plants grow well in Boise, Idaho?

Many plants thrive in Boise, including lilacs, serviceberry, yarrow, coneflowers, and various types of ornamental grasses. Consider native plants for drought tolerance and adaptability.

How do I protect my plants during a hard freeze in Boise?

Cover sensitive plants with blankets or burlap, mulch around the base of plants to insulate the roots, and water thoroughly before a freeze to help prevent dehydration.

Can I grow vegetables in Boise?

Yes! Boise has a growing season long enough to support many vegetables. Popular choices include tomatoes, peppers, zucchini, beans, and lettuce. Start seeds indoors early to maximize the growing season.

Where can I find information about local gardening events in Boise?

Check with the Idaho Botanical Garden, local nurseries, and the University of Idaho Extension office for information on gardening workshops, plant sales, and other events.

Is Boise considered a desert climate?

Boise has a semi-arid climate, characterized by hot, dry summers and cold winters with relatively low precipitation.

Summary

Understanding Boise’s planting zones (6b and 7a) is essential for successful gardening. By selecting plants that are hardy to these zones and considering other environmental factors, you can create a thriving garden that enhances the beauty of your home and community.