Use this planting calendar to find the best times of the year to grow fruits, vegetables, herbs, flowers, and other popular plants in Hartsel, CO, based on the USDA Hardiness Zone 4a.
On this page:
Hartsel, CO Frost Dates & Growing Season
Last Spring Frost Date for Hartsel, CO
The average last frost date in spring for Hartsel is June 30th. For gardeners planting sensitive crops like tomatoes, peppers, and basil, it is generally recommended to wait until July 14th 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 Hartsel, CO
The average first frost date in fall for Hartsel is August 30th. 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 Hartsel, CO
Based on historical frost data, the estimated growing season length in Hartsel is approximately 61 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.
Hartsel, CO Planting Calendar
This weekly planting calendar displays the ideal windows for starting seeds, transplanting, and harvesting your plants.
Hartsel, CO Monthly Planting Recommendations
May
In May, recommended activities include direct sowing Pea (from May 19th to June 2nd), starting Coleus seeds indoors (from May 5th to May 19th), and starting Basil seeds indoors (from May 19th to June 2nd).
June
In June, recommended activities include direct sowing Radish (from June 2nd to June 16th), direct sowing Kale (from June 2nd to June 16th), and direct sowing Bok Choy (from June 2nd to June 16th).
July
In July, recommended activities include direct sowing Okra (from July 14th to July 28th), direct sowing Zucchini (from July 7th to July 21st), and direct sowing Cosmos (from July 7th to July 14th).