One of the first steps you take when you are estimating your gardening schedule is find your USDA Zone info. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

The best time to plant helianthemum in San Diego can be determined by referring to the USDA zone info.

Planting Calendar for Helianthemum

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

Helianthemum do ok in a little bit of cold which means that you can plant them just a bit earlier in the year than other plants that might not handle the cold.

The earliest that you can plant helianthemum in San Diego 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 helianthemum and expect a good harvest is probably October. Any later than that and your helianthemum may not have a chance to really do well. You can get started a couple of weeks earlier by starting your helianthemum indoors.

Last Frost Date

In San Diego the average date of last frost happens on January 31. You should expect an average low temperature of 35°F in the coldest months of winter.

It's important to remember that USDA zone info for San Diego is just an average and the actual date of last frost will vary from year to year. Half of the time in San Diego it frosts late in the year after January 31 so make sure that you are ready to protect your helianthemum in the event of one of those late frosts.

USDA Zone Info for San Diego

Here is the info for USDA Zone 10b.

Average Date of Last Frost (spring)	January 31
Average Date of First Frost (fall)	December 15
Lowest Expected Low	35°F
Highest Expected Low	40°F

This means that on a really cold year, the coldest it will get is 35°F. On most years you should be prepared to experience lows near 40°F.

Plants to Grow in San Diego

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