Before planting it is a good idea to find your USDA Zone info to estimate your garden schedule. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

You will be able to figure out when it's a good idea to plant nierembergia by checking out the USDA zone info for Longmont.

Planting Calendar for Nierembergia

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

Nierembergia do not do well in cold weather which means that you need to wait until it warms up after the last frost before you can plant them.

The earliest that you can plant nierembergia in Longmont 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. You probably don't want to wait any later than that or else your nierembergia may not have a chance to grow to maturity. You can get started a little bit earlier by starting your nierembergia indoors.

Last Frost Date

On average the last frost has passed is on April 15 in Longmont. In the coldest months of winter you should expect an average low temperature of -15°F.

Since the USDA zone info for Longmont is just an average the actual date of last frost is different every year. Half of the time in Longmont it frosts late in the year after April 15 so just be sure to be ready to cover your nierembergia in the event of a surprise late frost.

USDA Zone Info for Longmont

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 Longmont

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