Gardeners need to be aware of the last average spring frost date for their particular area. Cold temperatures will kill frost-sensitive plants. If you want to plant early, try pansies. They can take the cold and frost. See Plant Talk 1030 for information on how to grow pansies.
People in the Denver metropolitan area normally use Mother’s Day as a guide for when to plant. However, Denver had its last spring freeze on April 5 in 1977 and on June 8 in 2007. The average over the last ten years is May 5.
Last Frost Dates
Check your local forecast before planting frost-sensitive annuals and vegetables. If the forecast looks good for the next ten days starting the end of April or first of May, you should be safe to plant. There will be no guarantees but that is a place to start.
For more information, see the following
Colorado State University Extension fact sheet(s).