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.

A way of making a decision about when you can plant nierembergia is to check out the USDA zone info for La Mesa.

Planting Calendar for Nierembergia

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

Nierembergia are not cold tolerant which tells us that you need to wait until it warms up after the last frost has passed before you can plant them.

The earliest that you can plant nierembergia in La Mesa 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 nierembergia and expect a good harvest is probably September. You probably don't want to wait any later than that or else your nierembergia may not have a chance to grow to maturity. Starting your nierembergia indoors is a great way to get them started a couple of weeks earlier.

Last Frost Date

The average date of last frost is January 31 in La Mesa. In the coldest months of winter you can expect an average low temperature of 30°F.

Since the USDA zone info for La Mesa is not always accurate the actual date of last frost is different every year. Since half of the time in La Mesa you get a frost after January 31 be ready to cover your nierembergia if you have a surprise late frost.

USDA Zone Info for La Mesa

Here is the info for USDA Zone 10a.

Average Date of Last Frost (spring)	January 31
Average Date of First Frost (fall)	December 15
Lowest Expected Low	30°F
Highest Expected Low	35°F

This means that on a really cold year, the coldest it will get is 30°F. On most years you should be prepared to experience lows near 35°F.

Plants to Grow in La Mesa

You may be interested in your other planting guides for La Mesa.