Use this planting calendar to find the best times of the year to grow fruits, vegetables, herbs, flowers, and other popular plants in Alpine, CO, based on the USDA Hardiness Zone 4a.
On this page:
Alpine, CO Frost Dates & Growing Season
Last Spring Frost Date for Alpine, CO
The average last frost date in spring for Alpine is May 30th. For gardeners planting sensitive crops like tomatoes, peppers, and basil, it is generally recommended to wait until June 13th 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 Alpine, CO
The average first frost date in fall for Alpine is September 5th. 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 Alpine, CO
Based on historical frost data, the estimated growing season length in Alpine is approximately 98 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.
Alpine, CO Planting Calendar
This weekly planting calendar displays the ideal windows for starting seeds, transplanting, and harvesting your plants.
Alpine, CO Monthly Planting Recommendations
March
In March, recommended activities include starting Pansy seeds indoors (from March 21st to April 4th), starting Petunia seeds indoors (from March 21st to April 4th), and starting Snapdragon seeds indoors (from March 21st to April 4th).
April
In April, recommended activities include starting Marigold seeds indoors (from April 18th to May 2nd), starting Broccoli seeds indoors (from April 4th to April 18th), and starting Basil seeds indoors (from April 18th to May 2nd).
May
In May, recommended activities include direct sowing Chervil (from May 2nd to May 16th), direct sowing Fenugreek (from May 30th to June 13th), and direct sowing Cilantro (from May 16th to June 13th).
June
In June, recommended activities include direct sowing Cosmos (from June 6th to June 13th), direct sowing Lima Bean (from June 13th to June 27th), and direct sowing Cantaloupe (from June 6th to June 20th).