When to Plant Tomatoes in Utah? (Best Time)

Written by

William Golder


Dorian Goodwin

when to plant tomatoes in utah

Utah has a short growing season with about 170 frost-free days in a year, making it essential to know when to plant tomatoes in Utah before cultivating them.

After all, these crops do not develop well under frost or extreme heat, and to ensure a successful harvest, growers should start them around April 15 to June 15, with April being the best month for indoor planting, while May and June serve as the ideal time for outdoor gardening.

We’ve listed some rules below to help you narrow down your planting dates.

Best Time to Plant Tomatoes in Utah


It’s best to start your tomato garden under warm, spring weather, ideally two weeks after the last frost.

However, you can direct-sow seeds outside two weeks prior to the end of winter freeze and use row covers or black plastic to keep the plants warm. This method is preferable if you’re too impatient to wait.

Other rules for growing tomatoes in Utah are: 

  1. Start seeds indoors in a biodegradable pot six to eight weeks before the final frost. When the freezing period ends and the seedling has at least five true leaves, move the tomatoes outside.
  2. Make sure your seeds and transplants are mature and harvested before the first frost. Tomatoes grow best under daytime temperatures of 75 to 85℉ and will incur tissue damage and even death if exposed to a harsh winter freeze, however short.

Hence, give your crops sufficient time to grow (around 60 to 100 days, depending on the variety), and collect them when they’re ready.

Given that Utah usually has its final frost in May and June, these months would make for the best tomato growing time within the state. We’ve also listed the last and first frosts for some regions in Utah below for quick reference.

Location Last frost First frost
Alpine May 12 October 5
Delta May 23 September 24
Harrisville April 28 October 17
Hyde Park May 15 September 27
Millcreek May 1 October 12
Springville May 2 October 12

Planting Time Based on Hardiness Zones

Credit: ufseeds.com

Since Utah spans hardiness zones 4 to 9, we have the estimated ideal planting dates below.

Hardiness region Average final frost Plant outside Sow seeds indoors
4 April 24 May 8 February 28
5 April 7 April 21 February 11
6 April 1 April 15 February 5
7 March 22 April 5 January 26
8 March 13 March 27 January 17
9 February 6 February 20 December 12

Tips for Successful Tomatoes Cultivation in Utah

1. Select the right tomato varieties


Tomatoes are classifiable into two types: determinate and indeterminate.

Determinate tomatoes are suitable for gardeners with little space, while indeterminate varieties will require trellising due to their more significant heights (four feet vs. up to twenty feet, in comparison).

Though you can grow both in Utah, determinate varieties are the better choice because they fruit all at once, a huge advantage when considering Utah’s short planting season.

The best tomatoes to grow in the state are:

  1. Celebrity, Longkeeper, Oregon Spring, Roma, and Royal Chico tomatoes for determinate and semi-determinate fruits
  2. DX 52-12, Early Cascade, and Sweet 100 for indeterminate varieties
  3. Plus Pole King and Presto for hybrid tomatoes

2. Give tomatoes the proper soil conditions and space to grow


Aside from following the recommended Utah planting calendar, it’s essential to give tomatoes full sun and well-drained, sandy soil with an inch of compost every 100 square feet.

For growers who are using containers, select pots six inches deep and fill them with a sterile planting mix. The potted tomatoes should receive fourteen hours of fluorescent light per day and be hardened off for at least three days before transplanting.

We recommend sowing seeds ½ inch deep into the soil and in rows that are three feet apart. Regarding spacing between plants, 18 to 24 inches will do.

Remember to give tomatoes one to two inches of water per week and install wooden stakes if you have an indeterminate variety. In this case, the stakes should be pushed 1.5 feet into the soil and tied to the plants with cloth.


After determining when to plant tomatoes in Utah, you can start ordering transplants to grow at home. Two or three seedlings should be enough for one person to consume, or you can plant more tomatoes for your entire family. The choice is up to you!

In any case, do not bury the leaves of your crops when putting them into the soil, and make sure to select upright transplants without flowers as well. These steps will increase your chances of success so that you have tomatoes to harvest before July comes.

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