Use this planting calendar to find the best times of the year to grow fruits, vegetables, herbs, flowers, and other popular plants in Union, WA, based on the USDA Hardiness Zone 8b.
On this page:
Union, WA Frost Dates & Growing Season
Last Spring Frost Date for Union, WA
The average last frost date in spring for Union is May 5th. For gardeners planting sensitive crops like tomatoes, peppers, and basil, it is generally recommended to wait until May 19th before moving plants outdoors. Waiting these extra few weeks significantly reduces the risk of a late freeze damaging young transplants.
First Fall Frost Date for Union, WA
The average first frost date in fall for Union is October 20th. This date marks the approximate end of the growing season for tender plants. Gardeners should plan to harvest frost-sensitive vegetables or provide heavy protection (such as row covers) before this date to avoid crop loss.
Growing Season Length in Union, WA
Based on historical frost data, the estimated growing season length in Union is approximately 168 days. This duration determines which vegetable varieties have enough time to reach maturity before the winter cold sets in. Short-season varieties are recommended for crops that require a longer warm period.
Please note: These dates are climatological averages. Actual weather conditions vary by year. Always check the local 10-day forecast before planting.
Union, WA Planting Calendar
This weekly planting calendar displays the ideal windows for starting seeds, transplanting, and harvesting your plants.
Union, WA Monthly Planting Recommendations
February
In February, recommended activities include starting Leek seeds indoors (from February 24th to March 10th), starting Lavender seeds indoors (from February 24th to March 10th), and starting Snapdragon seeds indoors (from February 24th to March 10th).
March
In March, recommended activities include starting Coleus seeds indoors (from March 10th to March 24th), starting Tomatillo seeds indoors (from March 10th to March 24th), and starting Cabbage seeds indoors (from March 10th to March 24th).
April
In April, recommended activities include direct sowing Lentil (from April 21st to May 5th), direct sowing Mustard (from April 7th to April 21st), and direct sowing Alyssum (from April 21st to May 5th).
May
In May, recommended activities include direct sowing Jute (from May 19th to June 2nd), direct sowing Cosmos (from May 12th to May 19th), and direct sowing Sesame (from May 19th to June 2nd).