The USDA Zone info is a great tool for gardeners to help us estimate 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.

A common way of figuring out when it's possible to plant helianthemum is to refer to the USDA zone info for San Dimas.

Planting Calendar for Helianthemum

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

Since helianthemum do well in moderate cold you can plant them a little bit earlier in the year than more sensitive plants.

The earliest that you can plant helianthemum in San Dimas 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. If you wait any later than that and your helianthemum may not have a chance to grow to maturity. Starting your helianthemum indoors is a great way to get them started a little bit earlier.

Last Frost Date

The average date of last frost is January 31 in San Dimas. It might get as low as 30°F during the coldest months of winter.

Always keep in mind that USDA zone info for San Dimas is just an average and the actual date of last frost changes from year to year. Since half of the time in San Dimas you get a frost after January 31 be ready to protect your helianthemum in the event of one of those late frosts.

USDA Zone Info for San Dimas

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 Dimas

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