Morning Glories

Asked May 3, 2013, 9:12 AM EDT

I have 100 morning glory vines started in my basement and they have been inside for 7 weeks now. I need to get them in the ground. I started hardening them last week a couple hours a day and got up to 6 hours until the snow. All the 10 day forecasts show no frost and 40 degree nights after Sunday. Should I plant them Sunday?

Jefferson County Colorado flowers: annuals and herbaceous perennials

2 Responses

Morning Glories are not cold tolerant and should be planted after the last spring frost date. If you can continue to harden your plants off and wait until the weekend of May 10 then your chances of success will increase. As a rule of thumb the average last frost date for our area is after Mother’s Day. I’ve included a link regarding average frost date from the Planttalk Colorado pages ( that discusses further details as follows: 2018 - Last spring frosts The date of the last spring frost is important to home gardeners planning to set out frost-sensitive annuals, vegetables and even tropical container plants. Sometimes different frost dates are quoted for each area. This risk factor presents a choice for home gardeners. How much of a chance are you willing to take in placing a tender plant outdoors? For example, in Denver the last spring frost date at a 50 percent confidence level is May 2nd. This computes to a growing season of 157 days. If you want to be 80 percent confident frosts are past, it's May 12th. If you're not a risk taker and want to be 90 percent confident, wait until May 18th to plant. All dates are based on 47 years of data. The latest frost date in Denver was June 2nd in 1951. Please let us know if we can help any further.

Thank you. My lack of patience is getting the best of me, but I'll hold off until next weekend.