How To Grow Tomatoes and Peppers Successfully in Wyoming

Growers don’t need a greenhouse to grow vegetables successfully in Wyoming, but a few tricks will help get great yields.

On average tomatoes and peppers should be yielding 10 pounds per plant. Getting this kind of production takes a couple of easy tricks.

Growing season
and seed starting

It helps to know how long the average growing season is for the area where one is growing. The growing season technically starts after the last frost and lasts until the first frost. 

Most of Wyoming will have around 112 days during the growing season, with some areas in the Mountain West seeing only a short 50 days. Each year’s growing season will vary, but growers should plan on an average of 90 days.

Starting from seed opens up new opportunities for the vegetable varieties growers can buy at the store. 

A seed packet will have a days to harvest or maturity number listed, which should be well below 90 days – sweet corn should be around 70 days – for Wyoming. 

Tomato seeds are fast to germinate – about four to five days – whereas peppers can take 14 days or more. Add 14 to 21 days for the plant to get to transplant size of four to six true leaves. 

At transplant size, growers should start to harden the plant by taking it outside on nice days, then back into the house at night until they can plant outside for the growing season. 

There are varieties of tomatoes that do much better in Wyoming. These will have a harvest number of 70 days or less and are typically around eight ounces. 

While many love beefsteak tomatoes, they need an exceptionally long growing season which doesn’t fit Wyoming conditions. Growers should skip this variety.

Watering and
fertilizing tricks

The best and most efficient way to water a garden is with a soaker hose or drip tape. Keep the water on the ground and not up in the air. 

Another must-have tool for successful gardening is a water timer. Vegetables are not drought tolerant and must be watered consistently every day or every other day to produce, so a timer is a garden’s best friend. 

Tomatoes, peppers, eggplant, green beans and watermelon all love very warm soil, around 85 degrees Fahrenheit. This is hard to achieve in Wyoming, but not impossible with the help of black plastic laid over garden soil and irrigation infrastructure placed under the black plastic. This also creates a weed-free, water-wise garden.

The fertilizer used in a garden is very important. The first number on a box of fertilizer is the nitrogen content. 

For a vegetable garden and tomatoes, it should be 10 percent or less. Excess nitrogen will cause huge growth and attract insects, especially aphids. If nitrogen is high, growers should reduce fertilizer and hose off the bad bugs. 

Never use insecticides in a garden, they will kill pollinators, which are a grower’s best friends since they kill unwanted bugs. 

When amending the soil for a vegetable garden, avoid using manures. Manures can be contaminated with weed seeds; have excess salt, which makes manure “hot” and harbor a host of unknown bacteria and parasites.  

Catherine Wissner is the University of Wyoming Laramie County Extension horticulturist. She can be reached at cwissner@uwyo.edu or 307-633-4480.