Larry Sagers Horticultural Specialist Utah State University Extension Service Thanksgiving Point Office © All Rights Reserved
This is my first year as a gardener and I'm wondering when the last average frost day is in Salt Lake.
As I've never planted anything but house plants at this elevation and I am renting an apartment, we're going to plant all annuals this year to experiment until we have a home with a yard.
I have been working off a June 1st plan to plant everything outside and am starting my seeds indoors accordingly. I'm just wondering if June 1st is too late. Should I plan on putting everything in pots outside in the middle of May?
I've looked and looked, and though the frost date changes year to year, I can't find a generalization in any online almanac or gardening book.
Thanks, Mollee, the budding green thumb
The easiest way to get information on specific microclimates in our area is to log onto http://climate.usu.edu/utahclim/freeze/
On that site you will find the freezing temperature table which follows gives dates for the last spring and first fall freezes (32 F or lower) at each station with sufficient minimum temperature data for calculations to be performed.
The period for which records were available is shown in the table in the second column from the right. Three spring dates are given the average date of the last spring freeze and the earliest and latest dates on which the last spring freeze has occurred during the period of record. Similar dates are given for the first fall freeze.
The table also gives values for freeze free season. Values include average length of freeze free season for each station and the shortest and longest freeze free season during the period of record.
Frost free seasons are not necessarily suitable for growing your warm season crops. A good example is the 2001 growing season when temperatures dropped to near freezing in many locations. Even though the tomatoes and other warm season crops may not have frozen, they were severely stunted by the cold temperatures.
In general, sometime during the first two weeks of May is suitable for setting out plants.