Use this planting calendar to find the best times of the year to grow fruits, vegetables, herbs, flowers, and other popular plants in Johnstown, CO, based on the USDA Hardiness Zone 5b.
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Johnstown, CO Frost Dates & Growing Season
Last Spring Frost Date for Johnstown, CO
The average last frost date in spring for Johnstown is May 8th. For gardeners planting sensitive crops like tomatoes, peppers, and basil, it is generally recommended to wait until May 22nd 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 Johnstown, CO
The average first frost date in fall for Johnstown is October 4th. 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 Johnstown, CO
Based on historical frost data, the estimated growing season length in Johnstown is approximately 149 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.
Johnstown, CO Planting Calendar
This weekly planting calendar displays the ideal windows for starting seeds, transplanting, and harvesting your plants.
Johnstown, CO Monthly Planting Recommendations
February
In February, recommended activities include starting Impatiens seeds indoors (from February 27th to March 13th), starting Geranium seeds indoors (from February 27th to March 13th), and starting Begonia seeds indoors (from February 27th to March 13th).
March
In March, recommended activities include starting Basil seeds indoors (from March 27th to April 10th), starting Thyme seeds indoors (from March 13th to March 27th), and starting Oregano seeds indoors (from March 13th to March 27th).
April
In April, recommended activities include direct sowing Milk Thistle (from April 24th to May 8th), direct sowing Calendula (from April 24th to May 8th), and direct sowing Crimson Clover (from April 10th to April 24th).
May
In May, recommended activities include direct sowing Zinnia (from May 15th to May 29th), direct sowing Cantaloupe (from May 15th to May 29th), and direct sowing Lemon Balm (from May 8th to May 22nd).