Use this planting calendar to find the best times of the year to grow fruits, vegetables, herbs, flowers, and other popular plants in Northglenn, CO, based on the USDA Hardiness Zone 5b.
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Northglenn, CO Frost Dates & Growing Season
Last Spring Frost Date for Northglenn, CO
The average last frost date in spring for Northglenn is May 7th. For gardeners planting sensitive crops like tomatoes, peppers, and basil, it is generally recommended to wait until May 21st 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 Northglenn, CO
The average first frost date in fall for Northglenn 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 Northglenn, CO
Based on historical frost data, the estimated growing season length in Northglenn is approximately 150 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.
Northglenn, CO Planting Calendar
This weekly planting calendar displays the ideal windows for starting seeds, transplanting, and harvesting your plants.
Northglenn, CO Monthly Planting Recommendations
February
In February, recommended activities include starting Onion seeds indoors (from February 26th to March 12th), starting Snapdragon seeds indoors (from February 26th to March 12th), and starting Pansy seeds indoors (from February 26th to March 12th).
March
In March, recommended activities include starting Cabbage seeds indoors (from March 12th to March 26th), starting Moonflower seeds indoors (from March 26th to April 9th), and starting Kale seeds indoors (from March 26th to April 9th).
April
In April, recommended activities include direct sowing Lentil (from April 23rd to May 7th), direct sowing Poppy (from April 9th to April 23rd), and direct sowing Alfalfa (from April 9th to April 23rd).
May
In May, recommended activities include direct sowing Anise (from May 14th to May 21st), direct sowing Lima Bean (from May 21st to June 4th), and direct sowing Butternut Squash (from May 14th to May 28th).