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.

By checking out the USDA zone info for Sioux City you will be able to figure out when to plant primroses.

Planting Calendar for Primroses

Frost tolerance for primroses:	Very tolerant of frost.
When to plant:	Up to 7 weeks before last frost.

Primroses do well in a bit of cold which means that you can plant them a lot earlier in the year than other frost tender plants.

The earliest that you can plant primroses in Sioux City is February. However, you really should wait until March if you don't want to take any chances.

The last month that you can plant primroses and expect a good harvest is probably September. Any later than that and your primroses may not have a chance to really do well. Starting your primroses indoors is a great way to get them started a few weeks earlier.

Last Frost Date

The average date of last frost is April 15 in Sioux City. It might get as low as -20°F during the coldest months of winter.

It's important to remember that the actual date of last frost is just an average because it is based on the USDA zone info for Sioux City and it changes from year to year. Since half of the time in Sioux City there is a last frost after April 15 be ready to cover your primroses if you have one of those late frosts.

USDA Zone Info for Sioux City

Here is the info for USDA Zone 5a.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	-20°F
Highest Expected Low	-15°F

This means that on a really cold year, the coldest it will get is -20°F. On most years you should be prepared to experience lows near -15°F.

Plants to Grow in Sioux City

You may be interested in your other planting guides for Sioux City.