When to Plant Tomatoes and Peppers in Denver

When to Plant Tomatoes and Peppers in Denver

May 29, 2019 4 By dzordani

When is it safe to plant tomato and pepper plants in the Denver area?

It happens every year… columns of display racks crammed full of vibrant, green, tomato and pepper starts show up in the big box stores just begging to be planted in that vacant bed. A string of seventy degree days, no more than ten days into April, affirms to customers that spring has officially arrived in Denver. Happy couples peruse the various tomato and pepper varieties searching for their perennial favorites; Jalapeno, Beefsteak, Sun Gold. Some gardeners even have foresight enough to whip out their Iphone and scroll through the extended forecast. Not a freezing temperature in sight. Green light means go!

An excited couple carefully select their plants; two Beefsteaks, three Jalapenos, and happily hand over twenty-five dollars to the big-box, twenty-something, cashier. They race home, head immediately to the backyard, and plant their newest acquisitions in the sunniest spot in their garden. Two weeks later and the plants are looking fantastic; perky, acclimated, happy. Congratulations, you have officially got an early jump on the gardening season…

5280 heirlooms when to plant your tomato and pepper plants
Carefully trenched and mulched tomato plants

… Until a bomb cyclone, packing fifty mile an hour winds and freezing temperatures, drops a foot of branch busting snow on the metro area. Welcome to spring time in the Mile High City!

May 21, 2019… yes, really

What can you do, Denver’s weather is, well, unpredictable. The real question isn’t “what can you do?” but, “when should you do it?”

The unofficial planting date for tender annuals along Denver’s Front Range is Mother’s Day (usually between May 7th and May 12th). If you’ve lived in Denver for any length of time, then you know, the above image could be a shot taken from Mother’s Day or later (May 21, 2019 for example).

The best time to plant your heirloom tomato and pepper plants in the Denver area is…

When night time temperatures hover around the 50 degree mark. Anything below mid 40s and your tomato and pepper starts will just sit in the ground in suspended animation. Why risk it? Consider planting your peppers and tomatoes closer to Memorial Day. If the temperatures are right they will take off, easily catching up to plants put in the ground weeks before. Waiting a few weeks can make all the difference. For recommended heirloom tomato planting read my post on trenching your tomatoes.