The USDA Zone info is a great tool for gardeners to help us figure out your gardening schedule. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

You should be able to figure out when it's a good idea to plant osteospermum by looking at the USDA zone info for Holtville.

Planting Calendar for Osteospermum

Frost tolerance for osteospermum:	Tolerant of some frost.
When to plant:	Up to 5 weeks before last frost.

Osteospermum do well in moderate cold which tells us that you can plant them earlier than more sensitive plants.

The earliest that you can plant osteospermum in Holtville is January. However, you really should wait until February if you don't want to take any chances.

The last month that you can plant osteospermum and expect a good harvest is probably October. If you wait any later than that and your osteospermum may not have a chance to fully mature. If you are starting your osteospermum indoors then you might be able to get away with starting them a few weeks earlier.

Last Frost Date

In Holtville 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 Holtville is not always accurate the actual date of last frost changes from year to year. Half of the time in Holtville it frosts late in the year after January 31 so always be ready to protect your osteospermum if you have a late frost.

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.