One of the best tools that you have as gardeners to help us estimate 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.

By looking at the USDA zone info for Holtville it's possible to figure out when to plant alternaria.

Planting Calendar for Alternaria

Frost tolerance for alternaria:	Not tolerant of frost.
When to plant:	After the last frost when the weather gets warmer.

Alternaria require warm weather which tells us that you must wait until it warms up after all chance of frost has passed before you can plant them.

The earliest that you can plant alternaria in Holtville 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 couple of weeks earlier.

Last Frost Date

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

Just be sure to remember that USDA zone info for Holtville is not always accurate and the actual date of last frost changes from year to year. Half of the time in Holtville there is a last frost after January 31 so always be ready to cover your alternaria in the event of one of those late frosts.

USDA Zone Info for Holtville

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 Holtville

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