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

The USDA zone info for Santa Clara can be reviewed to determine when it's a good idea to plant helianthemum.

Planting Calendar for Helianthemum

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

Since helianthemum are moderately cold tolerant you can plant them a little bit earlier in the year than more sensitive plants.

The earliest that you can plant helianthemum in Santa Clara 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 helianthemum and expect a good harvest is probably September. You probably don't want to wait any later than that or else your helianthemum may not have a chance to really do well. Starting your helianthemum indoors is a great way to get them started a couple of weeks earlier.

Last Frost Date

On average the last frost is on March 15 in Santa Clara. In the coldest months of winter you can expect an average low temperature of 10°F.

Since the USDA zone info for Santa Clara is not always accurate the actual date of last frost is different every year. Since half of the time in Santa Clara you get surprised by a frost after March 15 be ready to cover your helianthemum in the event of a late frost.

USDA Zone Info for Santa Clara

Here is the info for USDA Zone 8a.

Average Date of Last Frost (spring)	March 15
Average Date of First Frost (fall)	November 15
Lowest Expected Low	10°F
Highest Expected Low	15°F

This means that on a really cold year, the coldest it will get is 10°F. On most years you should be prepared to experience lows near 15°F.

Plants to Grow in Santa Clara

You may be interested in your other planting guides for Santa Clara.