Use this planting calendar to find the best times of the year to grow fruits, vegetables, herbs, flowers, and other popular plants in Niwot, CO, based on the USDA Hardiness Zone 5b.
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Niwot, CO Frost Dates & Growing Season
Last Spring Frost Date for Niwot, CO
The average last frost date in spring for Niwot 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 Niwot, CO
The average first frost date in fall for Niwot 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 Niwot, CO
Based on historical frost data, the estimated growing season length in Niwot 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.
Niwot, CO Planting Calendar
This weekly planting calendar displays the ideal windows for starting seeds, transplanting, and harvesting your plants.
Niwot, CO Monthly Planting Recommendations
February
In February, recommended activities include starting French Lavender seeds indoors (from February 27th to March 13th), starting Snapdragon seeds indoors (from February 27th to March 13th), and starting Impatiens seeds indoors (from February 27th to March 13th).
March
In March, recommended activities include starting Broccoli seeds indoors (from March 13th to March 27th), starting Stevia seeds indoors (from March 13th to March 27th), and starting Statice seeds indoors (from March 13th to March 27th).
April
In April, recommended activities include direct sowing Poppy (from April 10th to April 24th), direct sowing California Poppy (from April 10th to April 24th), and starting Cantaloupe seeds indoors (from April 10th to April 24th).
May
In May, recommended activities include direct sowing Lima Bean (from May 22nd to June 5th), direct sowing Anise (from May 15th to May 22nd), and direct sowing Sunflower (from May 15th to May 29th).