It's Tomato Time!


Despite the dreary weather this past week, we’re still on our way to the best parts of summer - when tomatoes, melons, cucumbers, and squash are abundant! These plants are all warm season crops. “Warm season” mean that these plants’ seeds won’t germinate in cold soils, and they have a low tolerance for frosts. Believe it or not, we are now past Missoula’s Frost Free Date of May 19th, which means it’s time to plant these crops.

Missoula’s Frost Free Date is the 30 year average of when Missoula’s last recorded frost of the spring occurred. The data is collected at the Missoula International Airport by the National Climatic Data Center.

(For a more extensive list of warm season crops, check out this blog by Emily, though keep in mind you can plant these now.)


Keep in mind May 19th is an average. There is about a 30% chance we will have another frost after this date, so although it’s a good date to have marked in your calendar, you should still keep an eye on the weather report for overnight lows. Here are some things you can do to help protect your warm season crops from freezing temperatures. This was written for the fall, but applies to spring frosts too.

US Hardiness Zones

If that sounds like too much work and you’d rather just wait until after the frost, that is fine too. Many people play it safe and plant their tomatoes after Memorial Day. Be careful though—the later you wait to plant, the longer it’ll take to get tomatoes. Make sure you put your starts in the ground, so that they have time to produce well ahead of the average First Frost in Missoula, which is September 27th. Check to make sure your tomatoes will ripen in time by checking the days to maturity of your tomato variety. Garden Fundamentals elaborates on that here.

Want more info on how to care for the tomatoes you’ve planted? Sign up for our Tomato Workshop Thursday, July 18th. In the meantime, check out this blog post for more tips.

Happy Gardening Everyone!