USDA Plant Hardiness Zones
Hood County is Zone 8b
(Average low is 15°-20° F)
Average First Frost Date: Nov 11th
Average Last Frost Date: March 20th
Average Frost Days per year: 20-30
The USDA plant hardiness zones are based on the average annual extreme minimum temperature. This map was updated with changing weather patterns in 2023 and many areas were moved to a warmer zone. Hood County is currently listed as Zone 8b, with an average minimum of 15-20 degrees. However, in 2021, Hood county experienced a deep freeze which resulted in temperatures below 10 degrees Fahrenheit.
USDA Zones are based on the average winter low temperatures and are no guarantee that plants will survive any given winter. Knowing the zone you live in will serve as a general guide for planting perennial plants. Past weather conditions cannot predict the future, and as Hood County is right on the line between 8b and 8a, it is always better to err on the side of caution and look for plants that will be hardy to zones 8a or even 7b. There are other factors such as sun, shade, wind and moisture that will also greatly affect the hardiness of a plant.
For more detailed information about Plant Hardiness Zone Map and examples on how apply the PHZM when planting, consult a publication developed for the 2012 version of the PHZM:
Widrlechner, M.P., C. Daly, M. Keller, and K. Kaplan. 2012. Horticultural Applications of a Newly Revised USDA Plant Hardiness Zone Map. HortTechnology, 22: 6-19.
Hood County Chill Hours: 650-950
Many fruit trees need cold weather for good production of fruit. The cold weather requirement of dormant buds to grow, flower and develop properly is commonly referred to as the chilling requirement. Chill hours as shown in the map to the right are calculated by tracking the number of hours between 45° and 32° from Oct 1 – Feb 28/29th. Purchasing fruit trees that require around 800 chill hours will generally be the most successful in Hood County.
