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.

You should be able to determine when it's the best time to plant helianthemum by reviewing the USDA zone info for Placerville.

Planting Calendar for Helianthemum

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

You can plant helianthemum a bit earlier in the year because they are one of those plants that can tolerate a little bit of cold weather.

The earliest that you can plant helianthemum in Placerville 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 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 February 15 in Placerville. It might get as low as 20°F during the coldest months of winter.

Since the USDA zone info for Placerville is just an average the actual date of last frost changes from year to year. Half of the time in Placerville it frosts late in the year after February 15 so make sure that you are ready to protect your helianthemum if you have a surprise late frost.

USDA Zone Info for Placerville

Here is the info for USDA Zone 9a.

Average Date of Last Frost (spring)	February 15
Average Date of First Frost (fall)	December 15
Lowest Expected Low	20°F
Highest Expected Low	25°F

This means that on a really cold year, the coldest it will get is 20°F. On most years you should be prepared to experience lows near 25°F.

Plants to Grow in Placerville

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