Use this planting calendar to find the best times of the year to grow fruits, vegetables, herbs, flowers, and other popular plants in Seattle, WA, based on the USDA Hardiness Zone 9a.
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Seattle, WA Frost Dates & Growing Season
Last Spring Frost Date for Seattle, WA
The average last frost date in spring for Seattle is March 20th. For gardeners planting sensitive crops like tomatoes, peppers, and basil, it is generally recommended to wait until April 3rd 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 Seattle, WA
The average first frost date in fall for Seattle is November 15th. 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 Seattle, WA
Based on historical frost data, the estimated growing season length in Seattle is approximately 240 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.
Seattle, WA Planting Calendar
This weekly planting calendar displays the ideal windows for starting seeds, transplanting, and harvesting your plants.
Seattle, WA Monthly Planting Recommendations
January
In January, recommended activities include starting Petunia seeds indoors (from January 9th to January 23rd), starting Aubergine seeds indoors (from January 23rd to February 6th), and starting French Lavender seeds indoors (from January 9th to January 23rd).
February
In February, recommended activities include starting Marigold seeds indoors (from February 6th to February 20th), direct sowing Alfalfa (from February 20th to March 6th), and direct sowing Sorrel (from February 20th to March 6th).
March
In March, recommended activities include direct sowing Lentil (from March 6th to March 20th), direct sowing Alyssum (from March 6th to March 20th), and direct sowing Dill (from March 6th to March 20th).
April
In April, recommended activities include direct sowing Lima Bean (from April 3rd to April 17th), direct sowing Jute (from April 3rd to April 17th), and direct sowing Corn (from April 3rd to April 10th).