One of the first steps you take when you are figuring out 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.

The earliest that you can plant nierembergia in Three Rivers should be determined by looking at the USDA zone info.

Planting Calendar for Nierembergia

Frost tolerance for nierembergia:	Not tolerant of frost.
When to plant:	After all chance of frost has passed.

Since nierembergia do not do well in cold weather you need to wait until after the last frost has passed before you can plant them.

The earliest that you can plant nierembergia in Three Rivers 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. If you wait 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 Three Rivers the average date of last frost happens on April 15. You can expect an average low temperature of -15°F in the coldest months of winter.

Keep in mind that USDA zone info for Three Rivers may not be accurate from year to year and the actual date of last frost changes from year to year. Half of the time in Three Rivers last frost occurs after April 15 so always be ready to cover your nierembergia in the event of a late frost.

USDA Zone Info for Three Rivers

Here is the info for USDA Zone 5b.

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

This means that on a really cold year, the coldest it will get is -15°F. On most years you should be prepared to experience lows near -10°F.

Plants to Grow in Three Rivers

You may be interested in your other planting guides for Three Rivers.