Ask an Expert // When to Plant? That is the Question

When to Plant.jpg

Even if it is too early to plant, it’s never too early to start planning your garden. Learn from USU Extension gardening expert Taun Beddes when you can safely plant your vegetable garden.


One day it is sunny and warm, and the next day it is raining and cold. Or in northern Utah, it could even be snowing.

Determining when to plant a garden can be especially confusing in Utah’s unpredictable, varied climate where last-frost dates can vary by many days within just a few miles. Many experienced gardeners have planted and later lost their plants to frost.

As you determine when you should plant, consider the geographic characteristics of where you live. When a yard is located in a populated area or on a mountain bench, it usually has a longer growing season. Other areas located at slightly lower elevations where cold air drains and cannot escape have a shorter season. This is why local commercial orchards are generally located on benches. Additionally, urban and suburban areas are slightly warmer than surrounding areas due to the urban heat effect. Heat from buildings and warmth generated by sunlight reflected from roads and other surfaces increases temperatures and delays frost. It can be helpful to chat with a local farmer or experienced gardener in your area to determine what works for him or her regarding when to plant.

In addition to frost information, it is important to take into account the needs of the plants. Vegetables planted locally fall into four basic categories: hardy, semi-hardy, tender and very tender. Depending on which category a plant belongs to, planting dates vary from early spring until early summer. Consider the following:

  • Hardy vegetables, including asparagus, broccoli, cabbage, onions, peas and spinach, can be planted as soon as the soil is workable in early spring. This usually ranges between 45 and 60 days before the average last frost. These same vegetables can be safely planted until the average last frost date.
  • Semi-hardy plants, such as beets, carrots, lettuce and potatoes, can be planted one to two weeks after the hardy group. These can be planted until the average last-frost date.
  • Tender vegetables, such as celery, cucumbers, corn and most beans, should be planted on the average last-frost date.
  • Very tender plants, such as squash, beans, melons, tomatoes, eggplants and peppers, should not be planted until at least a week after the average last frost. Even if frost does not occur before this time, these plants will not grow well and are more susceptible to disease until warmer weather.

If you have lost plants to frost, you are not alone, and all you can do is try again.

Average Frost Dates for Various Utah Locations (Note that these dates are averages and can vary from year to year.)
        Frost Dates
City Last First Frost-Free Days
Alpine May 20 September 30 136
Blanding May 13 October 12 153
Cedar City May 10 October 5 148
Delta May 17 September 28 134
Farmington May 5 October 10 158
Fillmore May 16 October 4 140
Huntsville June 11 September 9  89
Kanab May 7 October 20 166
Lake Town June 15 September 10  87
Logan May 14 September 25 135
Morgan June 6 September 11 98
Moroni June 1 September 18 109
Ogden May 1 October 24 176
Park City June 9 September 1  92
Price May 12 October 7 148
Roosevelt May 18 September 25 130
Spanish Fork May 1 October 13 165
St. George April 6 October 28 205
Tooele May 7 October 14 159
Tremonton May 3 October 10 160

This article was written by Taun Beddes, Utah State University Extension horticulturist, 801-851-8460, taun.beddes@usu.edu




Ask an Expert // Three Tips for Tree Planting

Tree Planting Tips.jpgTrees are an integral part of landscaping, and it’s important to know the basics of starting them out right so they will flourish for many years to come. Here are answers to three frequently asked questions about tree planting.


When is the best time of year to plant?

Trees are best planted when they are still dormant with tight, unopened buds in the early to mid-spring after the soil has thawed. Cool temperatures and good soil moisture in the spring help trees get established. Fall planting also works well for many species, though watering is critical if the fall is dry. Summer planting of balled-and-burlapped and container plants can be successful, though hot temperatures, dry conditions and non-dormant trees make good care especially important and survival less sure. Bare-root trees should only be planted in spring while still dormant.

Which type of tree is best?

Landscape trees and shrubs can be obtained in four basic types: balled and burlapped, container/potted, bare root and tree spaded. Each type has advantages and disadvantages, and none is ideal for all situations. Bare-root trees have the most naturally formed root system and are less expensive, but they are not commonly available from nurseries. Balled and burlapped trees work well because they have been grown for several years in soil and are more likely to have a well-distributed root ball than potted trees. Potted or containerized trees are most likely to develop root system problems such as girdling roots and buried root collars. Spaded trees grow well but are not always available.

How large does the root ball need to be?

All four types need to have an adequate root system. A good rule of thumb is that the root system, root ball or container diameter or spread should be 10 to 12 inches for every inch of stem caliper (diameter at ground-line just above any basal swell). Therefore, a 3-inch caliper tree should have a 30 to 36-inch-wide root ball as a minimum. Root ball depth is not as critical as width, but should be deeper for larger trees.

For further information on planting trees and general tree information, visit forestry.usu.edu.


This article was written by Mike Kuhns, Utah State University Extension forestry specialist, 435-797-4056, mike.kuhns@usu.edu




Best Vegetables for the Wastach Front

best vegetables to plant in utah

Whether or not you have a green thumb, tips for gardening made easier are always helpful. With the planting season here, you may be wondering if there is a better variety of cucumber, tomato, lettuce or even peas that works better in the Wasatch Front area. Or maybe you didn’t even realize that some varieties do better in different areas.

Did you know there are five types of pumpkin and broccoli that do best?

And what type of sweet corn likes this area?

Thanks to a survey done last year, all this information has been put together for you! You can view and download the easy-to-read chart with all the varieties listed and even some information on seed suppliers.

Haven’t planted yet? It’s not too late.  Check out our “When to Plant” guide posted earlier this year. Be sure to pin it so you can reference it next year and be ahead of the game!

When to start planting garden in Utah livewellutah.org

Don’t live in Northern utah? Check out Dixie Gardener for gardening information for the Southern part of Utah.

We hope these resources make it easier to be successful with your garden this year!