When to plant tomatoes in Iowa?

Tomatoes are considered easy-to-grow fruits and are easy to maintain as long as they are planted in good soil. However, zones dictate the time of planting and the yield.

For instance, if you are in Iowa, you must understand that you fall under zone 5. You, therefore, will only get a high tomato yield if the time of planting was properly matched with the right season-between the first frost date and the last one.

So that’s it. You have done the proper timing. All that remains is to understand the consequences of taking the tomato seedling outdoors at the wrong time. Additionally, it is critical to time seeds indoor seed sowing and understands how the two tomato varieties behave. Below, we will look at that.

Quick Answer:

In general, the right time to plant tomatoes in Iowa is during the late spring months, precisely starting from May 10th through June. However, in Southern Iowa, planting can start as early as March 3rd. And the last date for Iowa tomato growing is June 18th.

When is the right time to grow tomatoes in Iowa?

When to plant tomatoes in Iowa

According to USDA zones, Iowa falls under zone 5. The growing of tomatoes in this region depends on the first frost date and the last frost date of zone 5. In this regard, growing tomatoes in Iowa will be properly timed if done in the late spring. That is starting from May to June 18th, 2018.

Tomato growth needs to be timed appropriately in Iowa because they can’t survive frost or temperatures falling below 49 degrees Fahrenheit. If you plant them too early, they will die. On the other hand, when planted too late, their fruition will be cut off by the first frost in the fall. Therefore, you have to strictly analyze the weather in Iowa, especially in the spring season. In particular, you will need to observe when the last frost appears.

If there hasn’t been any frost for 14 days, you are good to plant your tomatoes outdoors in Iowa. Again, Mother Nature may have some cool tricks! That is, the last frost comes out late or appears earlier. So, before taking your tomatoes outdoors, ensure that you have timed the weather accordingly.

When is the right time to plant tomato seeds in Iowa?

Whether the tomato you are about to grow is indeterminate or determinate, you are guaranteed that it may take about 45–55 days for the seedlings to come out. You are advised to grow them indoors and transplant them outdoors when the time is right.

Usually, the specific time to start them indoors will depend on the last average frost date. You then have to deduct approximately 55 to 60 days from it. You might also want to consider paying attention to the Iowa weather report.

Further, the proper technique for getting your tomatoes outside is introducing them outdoors for an hour while rooted in pots. Then you should increase the number of days they spend outside. Do so with a few numbers, but you can transfer the rest of the seedlings if they put up well.

How should tomatoes be planted in Iowa?

When to plant tomatoes in Iowa

Tomatoes thrive on soils that are deep, loamy, and well-drained. They grow best in mildly acidic conditions with pH ranging from 6.0 to 6.8, although they may also thrive in slightly alkaline conditions. For the highest harvests, tomatoes require a minimum of 6 hours of total exposure to the sun every day.

Determinate tomato varieties like “Celebrity” and “Patio Hybrid” may be planted in big 3- to 5-gallon pots for people who don’t have access to a yard.

Tomato spacing is determined by the cultivar’s growth pattern and the garden layout. Staked indeterminate varieties can be placed at 1.5 to 2-foot intervals inside a row. Tomatoes in wire cages should be spaced 2-3 feet apart.

Tomatoes allowed to spread should be separated by 3-4 feet away from each other. The distance between rows should be about 4.5 feet. You should grow determinate tomatoes in lines 4 feet apart from each other, with 1.5 to 2 feet between each tomato.

What does “determinate” or “indeterminate” tomato mean?

The terms pertain to the development habits of tomatoes. They are known to be tiny and compact. The plants grow to a particular height, then stop growing, bloom, and produce fruits briefly. The time frame for a determinate tomato is usually after a month and a half. An indeterminate tomato will keep growing, flowering, and bearing fruit up to the first frost.

As a result, harvesting from indeterminate varieties typically takes about three months. Harvests are often higher than with determinate kinds, although they mature slowly. They are huge, spreading plants that thrive well in mesh cages or staked gardens.


Growing tomatoes in Iowa is like growing them in any other region under zone 5. All you need to do is time the first frost and the last frost dates, start the seeds indoors earlier, and you are good to go.

Related article: Common Tomato Pruning Mistakes and How to Avoid Them