One of the best tools that you have as gardeners to help us estimate your gardening schedule is the USDA zone info. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

In Bismarck you can figure out when it's possible to plant tomatos by looking at the USDA zone info.

Planting Calendar for Tomatos

Frost tolerance for tomatos:	Not tolerant of frost.
When to plant:	After the last frost when the weather gets warmer.

Since tomatos are not cold tolerant you must wait until after the last frost before you can plant them.

The earliest that you can plant tomatos in Bismarck is May. However, you really should wait until June if you don't want to take any chances.

The last month that you can plant tomatos and expect a good harvest is probably August. You probably don't want to wait any later than that or else your tomatos may not have a chance to grow to maturity. If you are starting your tomatos indoors then you might be able to get away with starting them a little bit earlier.

Last Frost Date

On average the last frost when the weather gets warmer is on May 15 in Bismarck. You can expect an average low temperature of -30°F in the coldest months of winter.

Just be sure to remember that the actual date of last frost may not be accurate from year to year because it is based on the USDA zone info for Bismarck and it changes from year to year. Since half of the time in Bismarck last frost occurs after May 15 be ready to protect your tomatos in the event of one of those late frosts.

USDA Zone Info for Bismarck

Here is the info for USDA Zone 4a.

Average Date of Last Frost (spring)	May 15
Average Date of First Frost (fall)	September 15
Lowest Expected Low	-30°F
Highest Expected Low	-25°F

This means that on a really cold year, the coldest it will get is -30°F. On most years you should be prepared to experience lows near -25°F.

Plants to Grow in Bismarck

You may be interested in your other planting guides for Bismarck.