One of the best tools that you have as gardeners to help us determine your gardening schedule is the 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 USDA zone info for San Luis can be looked at to determine when it's the best time to plant alternaria.

Planting Calendar for Alternaria

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

It's a bad idea to plant alternaria until after all chance of frost has passed because they do not do well in cold weather.

The earliest that you can plant alternaria in San Luis 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 alternaria and expect a good harvest is probably September. You probably don't want to wait any later than that or else your alternaria may not have a chance to fully mature. If you are starting your alternaria indoors then you might be able to get away with starting them a little bit earlier.

Last Frost Date

In San Luis the average date of last frost happens on January 31. It might get as low as 30°F during the coldest months of winter.

Since the USDA zone info for San Luis may not be accurate from year to year the actual date of last frost will vary from year to year. Since half of the time in San Luis you get surprised by a frost after January 31 be ready to cover your alternaria if you have a surprise late frost.

USDA Zone Info for San Luis

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 San Luis

You may be interested in your other planting guides for San Luis.