One of the first steps you take when you are determining your gardening schedule is find your 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.

You can estimate when it's a good idea to plant zinnia in Rosemount by referring to the USDA zone info.

Planting Calendar for Zinnia

Frost tolerance for zinnia:	Not tolerant of frost.
When to plant:	After the last frost has passed.

It's not a good idea to plant zinnia until after the last frost because they require warm weather.

The earliest that you can plant zinnia in Rosemount 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 zinnia and expect a good harvest is probably August. If you wait any later than that and your zinnia may not have a chance to fully mature. If you are starting your zinnia indoors then you might be able to get away with starting them a couple of weeks earlier.

Last Frost Date

In Rosemount the average date of last frost happens on May 15. You should expect an average low temperature of -25°F in the coldest months of winter.

Remember that the actual date of last frost is just an average because it is based on the USDA zone info for Rosemount and it changes from year to year. Half of the time in Rosemount it frosts late in the year after May 15 so always be ready to cover your zinnia if you have one of those late frosts.

USDA Zone Info for Rosemount

Here is the info for USDA Zone 4b.

Average Date of Last Frost (spring)	May 15
Average Date of First Frost (fall)	September 15
Lowest Expected Low	-25°F
Highest Expected Low	-20°F

This means that on a really cold year, the coldest it will get is -25°F. On most years you should be prepared to experience lows near -20°F.

Plants to Grow in Rosemount

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