One of the best tools that you have as gardeners to help us determine your gardening schedule is the USDA zone info. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

In Ypsilanti you can determine when to plant nierembergia by using the USDA zone info.

Planting Calendar for Nierembergia

Frost tolerance for nierembergia:	Not tolerant of frost.
When to plant:	After the last frost.

Since nierembergia are not cold tolerant it's important to wait until after all chance of frost has passed before you can plant them.

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

The last month that you can plant nierembergia and expect a good harvest is probably August. Any later than that and your nierembergia may not have a chance to really do well. If you are starting your nierembergia indoors then you might be able to get away with starting them a couple of weeks earlier.

Last Frost Date

In Ypsilanti the average date of last frost happens on April 15. You can expect an average low temperature of -10°F in the coldest months of winter.

Always keep in mind that USDA zone info for Ypsilanti may not be accurate from year to year and the actual date of last frost will vary from year to year. Half of the time in Ypsilanti you get a frost after April 15 so just be sure to be ready to protect your nierembergia in the event of a surprise late frost.

USDA Zone Info for Ypsilanti

Here is the info for USDA Zone 6a.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	-10°F
Highest Expected Low	-5°F

This means that on a really cold year, the coldest it will get is -10°F. On most years you should be prepared to experience lows near -5°F.

Plants to Grow in Ypsilanti

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